TY - JOUR A1 - Pangerl, Jonas A1 - Müller, Max A1 - Rück, Thomas A1 - Weigl, Stefan A1 - Bierl, Rudolf T1 - Characterizing a sensitive compact mid-infrared photoacoustic sensor for methane, ethane and acetylene detection considering changing ambient parameters and bulk composition (N2, O2 and H2O) JF - Sensors and Actuators B: Chemical N2 - We present a sensitive and compact interband cascade laser (ICL) based photoacoustic setup for the detection of gaseous hydrocarbons and discuss its applicability towards trace gas analysis. We investigated the performance of the sensor for trace concentrations of methane, ethane and acetylene diluted in nitrogen. The excitation of methane and ethane was accomplished using one tunable diode laser, covering a range from 3360 to 3372 nm, which was replaced by a separate ICL at 3025 nm for acetylene detection. The influence of ambient parameters such as temperature, flow rate and pressure as well as potential cross-sensitivities towards O2 and H2O have been examined in terms of methane and acetylene detection. A series of simulations proved several of these influences to be attributed to relaxation effects. With a 3σ limit of detection (LoD) of 6.8 parts per billion (ppbV) in case of methane, 2.3 ppbV regarding ethane and 3.6 ppbV in terms of acetylene, the sensor demonstrates a great potential for applications in the field of trace gas analysis. KW - Acetylene KW - Cross-sensitivities KW - Ethane KW - Interband cascade laser KW - Methane KW - Photoacoustic spectroscopy KW - Relaxation effects Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-25868 N1 - Corresponding author: Jonas Pangerl VL - 352,1 SP - 1 EP - 12 PB - Elsevier ER - TY - JOUR A1 - Müller, Max A1 - Rück, Thomas A1 - Jobst, Simon A1 - Pangerl, Jonas A1 - Weigl, Stefan A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - An Algorithmic Approach to Compute the Effect of Non-Radiative Relaxation Processes in Photoacoustic Spectroscopy JF - Photoacoustics N2 - Successful transfer of photoacoustic gas sensors from laboratory to real-life applications requires knowledge about potential cross-sensitivities towards environmental and gas matrix changes. Multi-dimensional calibration in case of cross-sensitivities can become very complex or even unfeasible. To address this challenge, we present a novel algorithm to compute the collision based non-radiative efficiency and phase lag of energy relaxation on a molecular level (CoNRad) for photoacoustic signal calculation. This algorithmic approach allows to calculate the entire elaxation cascade of arbitrarily complex systems, yielding a theoretical photoacoustic signal. In this work the influence of varying bulk compositions, i.e. nitrogen (N2), oxygen (O2) and water (H2O) on the photoacoustic signal during methane (CH4) detection is demonstrated. The applicability of the algorithm to other photoacoustic setups is shown exemplary by applying it to the relaxational system investigated in [1]. Hayden et al. examined the effect of water on photoacoustic carbon monoxide (CO) detection. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-39935 N1 - Corresponding author: Max Müller VL - 26 PB - Elsevier ER - TY - CHAP A1 - Melekhov, Evgeny A1 - Abb, Valerius A1 - Lechner, Alfred A1 - Kammler, Martin ED - Ivanov, Artem ED - Bicker, Marc ED - Patzelt, Peter T1 - Development of a glass-fiber-based spectrometer for the determination of drug residues in groundwater T2 - Tagungsband 2. Symposium Elektronik und Systemintegration ESI 2020 "Intelligente Systeme und ihre Komponenten: Forschung und industrielle Anwendung" N2 - Within the scope of this project, a portable measuring device has been developed which enables a cost-effective analysis of organic substances from ppm to sub-ppm range, such as drug residues in groundwater. The measurement is carried out by means of a surface-enhanced Raman scattering effect (SERS effect) and an exchangeable sensor head. The sensor head used is a nanostructured optical glass fiber glued into a fiber cannula. The tip of the fiber has been processed to act as a SERS cell. The fiber cannula is connected to a freely movable patch cable by using an adapter. Para-thiocresol is used to characterize the SERS cells. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2174 SN - 978-3-9818439-4-1 SP - 101 EP - 109 ER - TY - CHAP A1 - Scherer, Leo A1 - Vitzthumecker, Thomas A1 - Bierl, Rudolf ED - Uhl, Christian ED - Walter, Michael ED - Stiehl, Annika T1 - Capacitive PCB sensor for the detection of insects in intelligent traps T2 - Applied Research Conference 2022 Conference Proceedings: 4th July 2022, University of Applied Sciences Ansbach (Onsite Conference) N2 - Reliable and fast detection of pest in the food processing and pharmaceutical industry is crucial to ensure hygienically safe, pure and healthy products. This is why intelligent traps, that are able to detect insects automatically are needed. For this, a capacitive PCB sensor is developed and tested, which could be a simplistic, low power solution to the problem. This includes design, footprint generation and simulation as well as testing different types of capacitve sensing against noise immunity and sensitivity to Blattella germanica, the German cockroach. It is shown that a single specimen can very well and reliably be detected by the developed sensor. KW - PCB layout generation KW - insect monitoring KW - pest detection KW - Capacitive sensing Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-55837 SP - 519 EP - 523 PB - Hochschule Ansbach CY - Ansbach ER - TY - JOUR A1 - Serbun, Pavel A1 - Bornmann, Benjamin A1 - Navitski, Aliaksandr A1 - Müller, Günter A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Stable field emission of single B-doped Si tips and linear current scaling of uniform tip arrays for integrated vacuum microelectronic devices JF - Journal of Vacuum Science & Technology B Nanotechnology and Microelectronics N2 - Advanced Si-based semiconductor technology is most suitable to fabricate uniform nanostructures as integrated field emitter arrays for novel vacuum electronic devices. In order to improve the field emission homogeneity and stability of p-type silicon tip arrays for pulsed sensor applications, the authors have systematically studied the influence of the fabrication parameters on the tip shape and on the specific operating conditions. Based on detailed design calculations of the field enhancement, they have fabricated two series of hexagonal arrays of B-doped Si-tips in a triangular arrangement. The first (second) type contains three (four) patches with different number of tips (1, 91, 547 and 1, 19, 1027, 4447 for the first and second type, respectively) of about 1 (2.5) μm height, ∼20 (20) nm apex radius, and 20 (10) μm pitch. The field emission properties of both individual tips and complete arrays were investigated with a field emission scanning microscope at a pressure of 10−9 mbar. The current plateau of these tips typically occurs at about 10 (3) nA and around 65 (25) V/μm field level. In this carrier saturation range, single tips provide the highest current stability (<5%) and optical current switching ratio (∼2.5). Fairly homogeneous emission of the tip arrays leads to an undershooting of the expected linear scaling of the mean plateau current as well as to a much improved current stability (<1%). Y1 - 2013 U6 - https://doi.org/10.1116/1.4765088 VL - 31 IS - 2 PB - AIP Publishing ER - TY - GEN A1 - Melekhov, Evgeny A1 - Abb, Valerius A1 - Weidauer, Tobias A1 - Kammler, Martin A1 - Lechner, Alfred T1 - Tunable Nanopillars as Surface Enhanced Raman Scattering (SERS) Active Structure for Optical Quartz Glass Fiber T2 - SMSI 2021 - Sensors and Instrumentation N2 - In this work, a simple cost effective method to create tunable self-assembled three-dimensional nanostructure array-like nanoantennas on a tip of an optical quartz glass fiber is described. The structures are prepared using lithography-less dry etching. Gold nanoparticles are used as an etching mask using a thin metal-film thermal dewetting technique. The structures are applied as sensor for label-free analysis of organic substances in ppb range, such as drug residues in groundwater. The measurements are carried out by means of a Surface-enhanced Raman scattering (SERS) effect, an exchangeable sensor head, and a portable Raman device. This method allows in situ applications. Parathiocresol is used as a model substance to characterize the SERS cells. For metallization, gold and silver are compared. Reproducible SERS enhancement factors up to 10 7 are evaluated. Y1 - 2021 SN - 978-3-9819376-4-0 U6 - https://doi.org/10.5162/SMSI2021/B8.2 SP - 153 EP - 154 PB - AMA Association for Sensors and Measurement ER - TY - CHAP A1 - Khaled, W. A1 - Bruhns, Otto T. A1 - Reichling, S. A1 - Böse, Holger A1 - Baumann, Michael A1 - Monkman, Gareth J. A1 - Egersdörfer, Stefan A1 - Meier, Alexander A1 - Klein, Dagmar A1 - Freimuth, Herbert A1 - Ermert, Helmut T1 - A haptic sensor-actuator-system based on ultrasound elastography and electrorheological fluids for virtual reality applications in medicine T2 - CARS 2003 : computer assisted radiology and surgery ; proceedings of the 17th International Congress and Exhibition London, June 25 - 28, 2003 N2 - Mechanical properties of biological tissue represent important diagnostic information and are of histological relevance (hard lesions, "nodes" in organs: tumors; calcifications in vessels: arteriosclerosis). The problem is, that such information is usually obtained by digital palpation only, which is limited with respect to sensitivity. It requires intuitive assessment and does not allow quantitative documentation. A suitable sensor is required for quantitative detection of mechanical tissue properties. On the other hand, there is also some need for a realistic mechanical display of those tissue properties. Suitable actuator arrays with high spatial resolution and real-time capabilities are required operating in a haptic sensor actuator system with different applications. The sensor system uses real time ultrasonic elastography whereas the tactile actuator is based on electrorheological fluids. Due to their small size the actuator array elements have to be manufactured by micro-mechanical production methods. In order to supply the actuator elements with individual high voltages a sophisticated switching and control concept have been designed. This haptic system has the potential of inducing real time substantial forces, using a compact lightweight mechanism which can be applied to numerous areas including intraoperative navigation, telemedicine, teaching, space and telecommunication. Y1 - 2003 SP - 1354 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Becker, Tatiana I. A1 - Raikher, Yuriy L. A1 - Stolbov, Oleg V. A1 - Böhm, Valter A1 - Zimmermann, Klaus T1 - Magnetoactive elastomers for magnetically tunable vibrating sensor systems JF - Physical Sciences Reviews N2 - Magnetoactive elastomers (MAEs) are a special type of smart materials consisting of an elastic matrix with embedded microsized particles that are made of ferromagnetic materials with high or low coercivity. Due to their composition, such elastomers possess unique magnetic field-dependent material properties. The present paper compiles the results of investigations on MAEs towards an approach of their potential application as vibrating sensor elements with adaptable sensitivity. Starting with the model-based and experimental studies of the free vibrational behavior displayed by cantilevers made of MAEs, it is shown that the first bending eigenfrequency of the cantilevers depends strongly on the strength of an applied uniform magnetic field. The investigations of the forced vibration response of MAE beams subjected to in-plane kinematic excitation confirm the possibility of active magnetic control of the amplitude-frequency characteristics. With change of the uniform field strength, the MAE beam reveals different steady-state responses for the same excitation, and the resonance may occur at various ranges of the excitation frequency. Nonlinear dependencies of the amplification ratio on the excitation frequency are obtained for different magnitudes of the applied field. Furthermore, it is shown that the steady-state vibrations of MAE beams can be detected based on the magnetic field distortion. The field difference, which is measured simultaneously on the sides of a vibrating MAE beam, provides a signal with the same frequency as the excitation and an amplitude proportional to the amplitude of resulting vibrations. The presented prototype of the MAE-based vibrating unit with the field-controlled “configuration” can be implemented for realization of acceleration sensor systems with adaptable sensitivity. The ongoing research on MAEs is oriented to the use of other geometrical forms along with beams, e.g. two-dimensional structures such as membranes. KW - adaptable sensor unit KW - amplification ratio KW - bending vibration KW - eigenfrequency KW - Magnetic field control KW - magnetoactive elastomer Y1 - 2020 U6 - https://doi.org/10.1515/psr-2019-0125 SN - 2365-659X VL - 7 IS - 10 SP - 1 EP - 28 PB - de Gruyter ER - TY - GEN A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. T1 - Spectroscopic Analysis of Magneto-Active Polymers (MAP) - Poster T2 - DFG-Tagung, Benediktbeuern, September 2017 Y1 - 2017 ER - TY - GEN A1 - Heinrich, Tobias A1 - Ketterl, Hermann T1 - AI to quantify biological diversity T2 - LANDSUPPORT Final Conference and the Save Our Soils Workshop, 27 -28 APRIL 2022, Portici, Italy N2 - The primary consumers of plant exudates – in exact fungi and bacteria, are representative for the soil succession level from bare soil, which is bacterial dominant to old growth forest constitute by fungal dominance. In a specified level of soil succession, a special kind of plant family benefits on the Fungal to Bacteria Ratio. The ability to determine this ratio in situ without complex chemical applications is part of the project Electronical Laboratory for Intelligent Soil Examination (ELISE). Several mechanical and optical tests on soil samples are covered within this Project. To analyze the fungal to bacteria ratio, samples are prepared automatically – in a defined and reproductive procedure – to generate slides for shadowing microscopy. The samples are observed by a camera, which is attached to a transmitted light microscope. The automatic analysis, done with computer vision algorithms, aims to quantify bacterial and fungal biomass in the actual sample view. Moreover, the algorithm can classify organisms according to their color and shape. To get a processable picture, several images from different focal levels must be taken through the sample thickness. Parts of each image, are in focus at the actual layer, are merged to a whole depth of field picture, by focus stacking. This produced picture is used to classify, locate and quantify – in first step filamentous organisms e.g. fungal by image sematic segmentation. The result represents an image sized mask, which indicates the class of fungi with class equivalate values at the pixel positions – covered by the organism. This information is used to calculate the fungal mass per gram soil. To quantify the bacterial biomass two approaches are implemented. For low density of bacterial existence, the individual bacteria is counted for a part of the field of view by an image detection algorithm to be extrapolate afterwards to the mass per gram soil. For high density of bacterial occurrence, specified regions of interest with only bacteria present are chosen. An image classification which has been pretrained by pictures of bacterial density patterns – previously determent by making the sample countable due to preforming sample dilutions, is done. The second option for high density bacterial count is, to automatically preform dilutions until the image detection is confidently countable. To ensure a usable confidence score a statistical approach of many fields of view is taken. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-50080 UR - https://www.landsupport.eu/wp-content/uploads/2022/04/210422-abstract-poster-v2.pdf ER - TY - GEN A1 - Ketterl, Hermann A1 - Heinrich, Tobias T1 - Vivid tool for comprehensive biological soil analysis T2 - LANDSUPPORT Final Conference and the Save Our Soils Workshop, 27 -28 APRIL 2022, Portici, Italy N2 - The sample preparation for shadowing microscopy, to examinate biological soil properties, is time consuming, manual work. The outcome depends on subjective skills of the operator, furthermore the results are mostly not quantitative. The database on biological soil properties is mostly not sufficient for an integrated modelling on an multidisciplinary scale. This project combines three progressive approaches to develop a tool that is easy to use and gives in situ results that can be used for many purposes. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-50078 UR - https://www.landsupport.eu/wp-content/uploads/2022/04/210422-abstract-poster-v2.pdf ER - TY - GEN A1 - van der Weerd, Bastiaan A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - A Conductivity Probe for Determination of the Carbon Dioxide Tension at the Oxygenator Exhaust Outlet during Extracorporeal Membrane Oxygenation (ECMO) T2 - Proceedings of the 9th ISC Modern Analytical Chemistry 2013, Prag Y1 - 2013 UR - https://www.gdch.de/fileadmin/downloads/Veranstaltungen/Tagungen/2014_Tagungen/analytica/poster_abstracts/sens03_vanderweerd_5860.pdf ER - TY - GEN A1 - Rück, Thomas A1 - Hofmann, Matthias A1 - Bierl, Rudolf T1 - Development of a miniaturized photoacoustic multigas sensing system for trace gas measurement T2 - 17th International Conference on Photoacoustic and Photothermal Phenomena, Oct. 20-24, 2013, Suzhou China Y1 - 2013 UR - https://www.gdch.de/fileadmin/downloads/Veranstaltungen/Tagungen/2014_Tagungen/analytica/poster_abstracts/sens05_rueck_5925.pdf ER - TY - GEN A1 - Rück, Thomas A1 - Matysik, Frank-Michael A1 - Bierl, Rudolf T1 - Development of a miniaturized photoacoustic multigas sensing system for trace gas measurement T2 - analytica conference 2014, 1. bis 4. April, München Y1 - 2014 UR - https://www.gdch.de/fileadmin/downloads/Veranstaltungen/Tagungen/2014_Tagungen/analytica/poster_abstracts/sens05_rueck_5925.pdf ER - TY - GEN A1 - Rück, Thomas A1 - Matysik, Frank-Michael A1 - Bierl, Rudolf T1 - Comparison of acoustic detectors for use in miniaturized photoacoustic devices designed for nitrogen dioxide trace gas measurement T2 - ANAKON, 23.-26.3.2015, Graz Y1 - 2015 ER - TY - JOUR A1 - Pangerl, Jonas A1 - Sukul, Pritam A1 - Rück, Thomas A1 - Fuchs, Patricia A1 - Weigl, Stefan A1 - Miekisch, Wolfram A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - An inexpensive UV-LED photoacoustic based real-time sensor-system detecting exhaled trace-acetone JF - Photoacoustics N2 - n this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) – providing clinically relevant information about the human health. This is achieved via the development of a CO2-triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis. The new sensor system provided a 3σ detection limit of 8.3 ppbV and an NNEA of 1.4E-9 Wcm 1Hz 0.5. In terms of the performed breath analysis measurements, 12 out of 13 fell within the error margin of the photoacoustic measurement system, demonstrating the reliability of the measurements in the field. KW - Photoacoustic spectroscopy KW - Real-time mass-spectrometry KW - Breath analysis KW - Acetone KW - UV-LED Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-71279 SN - 2213-5979 N1 - Corresponding author der OTH Regensburg: Jonas Pangerl VL - 38 PB - Elsevier ER - TY - JOUR A1 - Escher, Lukas A1 - Rück, Thomas A1 - Jobst, Simon A1 - Pangerl, Jonas A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - Photodissociation-Driven Photoacoustic Spectroscopy with UV-LEDs for Ozone Detection JF - Photoacoustics N2 - This study presents the development and evaluation of a UV-LED based photoacoustic (PA) measurement system for ozone (O3) detection to demonstrate its potential for low-cost and accurate sensing while for the first time addressing the importance of photodissociation for PA signal generation for O3 in the UV range. With a detection limit of 7.9 ppbV, the system exhibits a significant advancement over state-of-the-art UV-PA O3 detection and is on par with laser-based setups. Following a novel discussion of the PA signal arising from photodissociation and its products, cross-sensitivity effects due to environmental factors such as temperature and gas composition were systematically analyzed. A digital twin driven compensation for these influences was implemented and evaluated. Despite the challenges associated with modeling the effects of H2O and CO2, the PA system shows considerable potential, though further studies in real world applications must be conducted. KW - Photoacoustic spectroscopy KW - UV-LED KW - Ozone KW - Photodissociation KW - Cross-sensitivity Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-80076 SN - 2213-5979 N1 - Corresponding author der OTH Regensburg: Lukas Escher VL - 43 PB - Elsevier BV ER - TY - JOUR A1 - Hausler, Peter A1 - Holzner, Lukas A1 - Ehrnsperger, Matthias A1 - Bierl, Rudolf T1 - Evaluation of the creep strength of samples produced by fused deposition modeling JF - Open Engineering N2 - Data sheets for 3D printing materials typically include softening temperature, impact strength, tensile strength, and stiffness. However, creep strength, an important parameter for components used over an extended period, is usually not included. Nevertheless, this parameter is of significant importance for components that are used over an extended period of time.This study compares the long-term creep behavior of a selection of materials that are commonly used in fused deposition modeling 3D printing. The materials under investigation are acrylonitrile butadiene styrene, acrylonitrile styrene acrylate, polylactic acid, and polycarbonate. In addition, the influence of fiber reinforcements on these materials is also examined. A simple, reproducible test procedure is proposed for users to determine and compare creep resistance of materials. This enables developers to select materials suitable for their own requirements on creep resistance and allows 3D-printing users to compare different materials. Results suggest that fiber reinforcement generally improves creep stability in 3D-printing materials, with GreenTEC Pro Carbon and add:north PC Blend HT LCF showing the most promise in this study. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-79760 N1 - Corresponding author der OTH Regensburg: Peter Hausler VL - 14 IS - 1 PB - de Gruyter ER - TY - JOUR A1 - Schels, Andreas A1 - Edler, Simon A1 - Herdl, Florian A1 - Hansch, Walter A1 - Bachmann, Michael A1 - Ritter, Daniela A1 - Dudeck, Markus A1 - Duesberg, Felix A1 - Meyer, Manuel A1 - Pahlke, Andreas A1 - Hausladen, Matthias A1 - Buchner, Philipp A1 - Schreiner, Rupert T1 - In situ quantitative field emission imaging using a low-cost CMOS imaging sensor JF - Journal of Vacuum Science & Technology B N2 - Spatially resolved field emission measurements represent an important factor in further development of existing field emitter concepts. In this work, we present a novel approach that allows quantitative analysis of individual emission spots from integral current-voltage measurements using a low-cost and commercially available CMOS camera. By combining different exposure times to extrapolate oversaturated and underexposed pixels, a near congruence of integral current and image brightness is shown. The extrapolation also allows parallel investigation of all individual tips participating in the total current with currents ranging from a few nanoampere to one microampere per tip. The sensitivity, which is determined by the integral brightness-to-current ratio, remains unchanged within the measurement accuracy even after ten full measurement cycles. Using a point detection algorithm, the proportional current load of each individual tip of the field emitter array is analyzed and compared at different times during the initial measurement cycle. Together with the extracted I-V curves of single emission spots from the integral measurement, the results indicate the effect of premature burnout of particularly sharp tips during conditioning of the emitter. KW - ARRAYS KW - ELECTRON-EMISSION KW - EMITTERS KW - FakANK Y1 - 2022 U6 - https://doi.org/10.1116/6.0001551 VL - 40 IS - 1 PB - AIP Publishing ER - TY - JOUR A1 - Engelhardt, Lucas A1 - Melzner, Maximilian A1 - Havelkova, Linda A1 - Fiala, Pavel A1 - Christen, Patrik A1 - Dendorfer, Sebastian A1 - Simon, Ulrich T1 - A new musculoskeletal AnyBodyTM detailed hand model JF - Computer Methods in Biomechanics and Biomedical Engineering N2 - Musculoskeletal research questions regarding the prevention or rehabilitation of the hand can be addressed using inverse dynamics simulations when experiments are not possible. To date, no complete human hand model implemented in a holistic human body model has been fully developed. The aim of this work was to develop, implement, and validate a fully detailed hand model using the AnyBody Modelling System (AMS) (AnyBody, Aalborg, Denmark). To achieve this, a consistent multiple cadaver dataset, including all extrinsic and intrinsic muscles, served as a basis. Various obstacle methods were implemented to obtain with the correct alignment of the muscle paths together with the full range of motion of the fingers. These included tori, cylinders, and spherical ellipsoids. The origin points of the lumbrical muscles within the tendon of the flexor digitorum profundus added a unique feature to the model. Furthermore, the possibility of an entire patient-specific scaling based on the hand length and width were implemented in the model. For model validation, experimental datasets from the literature were used, which included the comparison of numerically calculated moment arms of the wrist, thumb, and index finger muscles. In general, the results displayed good comparability of the model and experimental data. However, the extrinsic muscles showed higher accordance than the intrinsic ones. Nevertheless, the results showed, that the proposed developed inverse dynamics hand model offers opportunities in a broad field of applications, where the muscles and joint forces of the forearm play a crucial role. KW - Musculoskeletal KW - hand KW - AnyBody KW - inverse dynamics KW - moment arm Y1 - 2020 U6 - https://doi.org/10.1080/10255842.2020.1851367 VL - 24 IS - 7 SP - 777 EP - 787 PB - Taylor & Francis ER - TY - CHAP A1 - Tschurtschenthaler, Karl A1 - Krenkel, Lars A1 - Schreiner, Rupert T1 - Mechano-optical micro pillar sensor for biofluidmechanic wall shear stress measurements T2 - 25th Congress of the European Society of Biomechanics (ESB), July 7-10, 2019, Vienna, Austria Y1 - 2019 UR - https://esbiomech.org/conference/archive/2019vienna/Contribution_608.pdf ER - TY - CHAP A1 - Weber, Karsten ED - Kerkelmann, Friederike ED - Lewandowski, Dirk T1 - Alternative Benutzerschnittstellen als Möglichkeit der Kompensation sensorischer Handicaps T2 - Barrierefreie Informationssysteme: Zugänglichkeit für Menschen mit Behinderung in Theorie und Praxis Y1 - 2015 U6 - https://doi.org/10.1515/9783110337297-004 SP - 49 EP - 70 PB - de Gruyter CY - Berlin ER - TY - CHAP A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Stable and low noise field emission from single p-type Si-tips T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - Single gated p-type Si-tips with two different tip radii were fabricated. An emission current of 2.40 μA was measured for the sharp-edged tip at a voltage of 170 V. In contrast, a stable and reproducible emission behavior was observed with an increased tip radius resulting in a pronounced saturation region between 90 V and 150 V, but merely an emission current of 0.55 μA at 150 V. More remarkable is the stable emission behavior with fluctuation of ± 4 % during a measurement period of 30 minutes. The integral emission current in a homogeneous tip array (16 emitters) showed nearly the same I-V characteristics compared to the single tip and is therefore, most dominated by only a stable single tip in the array. KW - field emission KW - p-type Si-tips KW - gate-electrode KW - emission stability KW - low current fluctuations Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520018 PB - IEEE ER - TY - CHAP A1 - Lindner, Matthias A1 - Berndt, Dominik A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Field emission assisted micro plasma discharges at vacuum and atmospheric pressures T2 - 31st International Vacuum Nanoelectronics Conference (IVNC), 2018, Kyoto, Japan N2 - Spatially confined non-equilibrium plasmas at vacuum and atmospheric pressure in the dimensions from a few microns to one millimeter are a promising approach to the generation and maintenance of stable glow discharges. The realization of these micro-discharges or micro-plasmas enable more accurate investigations in the field of micro plasma research. We report on field emission assisted micro plasmas excited by an alternating current with frequencies up to 1 kHz. Due to the field enhancement caused by an array of Si nano-tip structures the ignition voltage of stable plasma discharges can be reduced by 30%. Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520181 ER - TY - CHAP A1 - Berndt, Dominik A1 - Lindner, Matthias A1 - Tschurtschenthaler, Karl A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Miniaturized Plasma Actuator Flow Measurements by MEMS-Based Thermal Conductivity Sensors T2 - MDPI Proceedings of Eurosensors 2018, 9-12 September, Graz N2 - The gasflow created by a minaturized dielectric barrier discharge (DBD) plasma actuator is measured by a MEMS-based thermal conductivity gas sensor giving an indication of flow velocity and flow direction. The possiblity of several sensors in a small area gives a far better accuracy of local flow phenomena compared to conventional sensors. This is important for a better understanding of plasma- induced flow characteristics. KW - thermal conductivity sensors; plasma actuators; surface hotfilms; sensors for aerospace Y1 - 2018 U6 - https://doi.org/10.3390/proceedings2130939 VL - Vol.13 IS - 2 ER - TY - CHAP A1 - Steindl, Michael A1 - Mottok, Jürgen A1 - Meier, Hans A1 - Schiller, Frank A1 - Früchtl, M. T1 - Safeguarded Processing of Sensor Data T2 - IT-SecurityArea (IT-SA 2009) vom 13.-15. Oktober 2009, Nürnberg N2 - The spectrum of software tasks no longer includes only rare function controlling tasks for sensor actuator chains in reactive embedded systems. However, more and more responsible challenges like safety-critical scenarios are tackled. Therefore sensor data have to be safeguarded by several mechanism. An obvious and widely used approach is the use of two redundant hardware controllers, but this comes along with an additional cost, space and energy factor. Another way to fulfill certain safety properties is to implement a second diverse software channel in a single micro-controller architecture according the Safely Embedded Software (SES) approach. However, a lack of performance occurs by implementing this diverse channel for complex computations e.g. floating-point operations. This paper gives an approach for transferring the SES into a coprocessor and to migrate SES to a flexible and powerful FPGA architecture. KW - Safety embedded software KW - FPGA KW - Diverse instructions KW - Safety code weaving Y1 - 2009 UR - https://hal.archives-ouvertes.fr/hal-02268737 ER - TY - CHAP A1 - Steindl, Michael A1 - Mottok, Jürgen A1 - Meier, Hans A1 - Schiller, Frank A1 - Früchtl, M. T1 - Safeguarded Processing of Sensor Data T2 - 5th Embedded Real Time Software and Systems Conference (ERTS2 2010), May 2010, Toulouse, France Y1 - 2010 ER - TY - CHAP A1 - Edler, Simon A1 - Hansch, Walter A1 - Prommesberger, Christian A1 - Schreiner, Rupert T1 - Influence of adsorbates on the performance of a field emitter array in a high voltage triode setup T2 - International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan N2 - The influence of residual gas pressure on the characteristics of black-Silicon field emitter arrays in a high voltage triode setup is investigated. I-Vcharacteristics at different pressure levels show a decrease of emission current with rising pressure. This can be explained by an increase of the work function and charging of the emitter surface due to adsorbates. The initial characteristics can be restored by heating the FEA up to 110 °C during electron emission. This regeneration procedure enables an extension of the lifetime from about 20 h to 440 h at a residual gas pressure of 10 -5 mbar. KW - semiconductor field emission KW - field emitter array KW - silicon tips KW - emission current stability Y1 - 2018 U6 - https://doi.org/10.1109/IVNC.2018.8520214 PB - IEEE ER - TY - CHAP A1 - Käsbauer, Johannes A1 - Schmailzl, Anton A1 - Prehm, Jens A1 - Loose, Tobias A1 - Hierl, Stefan T1 - Simulation of Quasi-Simultaneous Laser Transmission Welding of Plastics BT - Optimization of Material Parameters in Broad Temperature Range T2 - Procedia CIRP N2 - Thermo-mechanical simulation offers great opportunities to optimize welding processes of plastics. For realistic simulation, the temperature dependent mechanical properties need to be implemented from ambient temperature to temperatures above the flow temperature. Standard test methods are insufficient for characterization in the entire temperature range because close to the flow temperature the material is too soft for tensile tests and too stiff for rheometry. Therefore, an optimization strategy is developed, that determines unknown material parameters by testing in welding simulations. The unknown parameters are iteratively adjusted to minimize the mismatch between computed and measured set-paths. Thus, important process characteristics are calculated realistically, enabling the computer aided assessment of the weld quality. KW - plastics welding KW - simulation KW - material modelling KW - optimization KW - parameterization KW - Kunststoffschweißen KW - Thermomechanische Eigenschaft KW - Simulation Y1 - 2020 U6 - https://doi.org/10.1016/j.procir.2020.09.136 VL - 94 SP - 737 EP - 741 PB - Elsevier ER - TY - JOUR A1 - Weigl, Stefan A1 - Feldmeier, Florian A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - Photoacoustic detection of acetone in N2 and synthetic air using a high power UV LED JF - Sensors Actuators B Chemical N2 - The performance of a photoacoustic trace gas sensor for the detection of acetone in N2 and synthetic air is reported. The sensor system utilises an amplitude modulated UV LED. The light source has an emission maximum at 278 nm and a maximum CW output power of 300 mW according to the datasheet. Three different collimating and focusing approaches have been investigated to guide the highly divergent LED light into the acoustic resonator of the photoacoustic measurement cell. A 3D printed aluminium cell was designed to optimize light coupling by simultaneously minimizing the photoacoustic background signal generation. Hence, the diameter of the resonator was set to a comparable large diameter of 10 mm and the inner walls of the resonator were mirror polished. The additive manufacturing procedure allowed for integration of a spirally formed gas channel, enabling gas heating prior to detection. The sensor performance was investigated by measuring acetone in N2 and synthetic air at different concentrations. The UV LED current was set to 86 % of the maximum value according to the datasheet of the light source in order to increase the lifetime and thermal stability. An Allan-Werle deviation analysis validates a stable sensor performance. The limit of detection (LoD) was determined at a 3σ noise level with a 10 s lock-in amplifier time constant by sampling data points over 20 s with a data acquisition rate of 5 Hz. LoDs of 80.8 ppbV and 19.6 ppbV were obtained for acetone in N2 and synthetic air, respectively. KW - Acetone detection KW - Photoacoustic spectroscopy KW - High power UV LED KW - UV LED collimation system KW - Acetone breath analysis Y1 - 2020 U6 - https://doi.org/10.1016/j.snb.2020.128109 N1 - Corresponding author at: Sensorik-Applikationszentrum (SappZ) der Ostbayerischen Technischen Hochschule Regensburg VL - 316 IS - August SP - 1 EP - 11 PB - Elsevier ER - TY - JOUR A1 - Berndt, Dominik A1 - Muggli, Josef A1 - Wittwer, Franz A1 - Langer, Christoph A1 - Heinrich, Stephan A1 - Knittel, Thorsten A1 - Schreiner, Rupert T1 - MEMS-based thermal conductivity sensor for hydrogen gas detection in automotive applications JF - Sensors and Actuators A: Physical N2 - Accurate detection of hydrogen gas in vehicle interiors is very important for the future of a fuel cell car. Since this type of gas is highly volatile and flammable, the measurement methods have to be very reliable and precise due to safety reasons. In this paper a thermal conductivity sensor for hydrogen gas detection is presented, exhibiting a lower detection limit of 2000 ppm hydrogen in laboratory air. The sensor element is realized by micro-fabrication techniques on silicon wafers. The heated filament is exposed by a selective wet etching process creating a micro-hotplate on a thin membrane. In order to minimize power consumption, the sensor is operated in pulsed mode. Hydrogen gas detection was carried out using a synthetic gas testbench. Measurements of hydrogen contents ranging from 0% to 4% with an increment of 0.5% were successfully performed for ambient gas temperatures between -15°C and 84°C. Including humidity, high moisture contents have the greatest influence on thermal conductivity. This was predicted in theoretical investigations and confirmed in experiments. For evaluation, both the change in resistance ΔR as well as the time constant τ were taken as sensor output. For both quantities, the previously established theoretical relationship with thermal conductivity could be confirmed. Y1 - 2020 U6 - https://doi.org/10.1016/j.sna.2019.111670 VL - 305 IS - April PB - Elsevier ER - TY - JOUR A1 - Weigl, Stefan A1 - Wittmann, Elisabeth A1 - Rück, Thomas A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - Effects of ambient parameters and cross-sensitivities from O2, CO2 and H2O on the photoacoustic detection of acetone in the UV region JF - Sensors Actuators B Chemical N2 - We present a sensitive UV LED photoacoustic setup for the detection of gaseous acetone and discuss its applicability towards breath analysis. We investigated the performance of the sensor for low acetone concentrations down to 0.1 parts per million (ppmV). The influences of temperature, flow, pressure, optical power and LED duty cycle on the measured signal have been examined. To gain a better understanding of the different effects on the photoacoustic signal, correlation analysis was applied and feature importance was determined using a large measured dataset. Furthermore, the cross-sensitivities towards O2, CO2 and H2O have been studied extensively. Finally, the sensor’s performance to detect acetone between 0.1–1 ppmV within gas mixtures simulating breath exhale conditions has been investigated, too. With a limit of detection (LoD) of 12.5 parts per billion (ppbV) (3σ) measured under typical breath exhale gas mixture conditions, the sensor demonstrated a high potential for the application of acetone detection in human breath analysis. KW - Acetone detection KW - Photoacoustic spectroscopy KW - High power UV LED KW - Cross-sensitivities KW - Acetone breath analysis Y1 - 2021 U6 - https://doi.org/10.1016/j.snb.2020.129001 SN - 0925-4005 N1 - Corresponding authors: Stefan Weigl, Elisabeth Wittmann, Thomas Rück, Rudolf Bierl, Frank-Michael Matysik N1 - Corrigendum to “Effects of ambient parameters and cross-sensitivities from O2, CO2 and H2O on the photoacoustic detection of acetone in the UV region” [Sens. Actuators B: Chem. 328 (February 2021) (2020) 129001]; https://doi.org/10.1016/j.snb.2020.129392 IS - 328 PB - Elsevier ER - TY - CHAP A1 - Schubert, Martin J. W. A1 - Seign, Stefan A1 - Dai, Q. A1 - Hinterseer, Sebastian A1 - Pielmeier, F. A1 - Pietsch, Alexander A1 - Seebauer, C. A1 - Weiß, Josef A1 - Yu, C. A1 - Zenger, Stefan T1 - Capacitive Sensor Technology for Soil Moisture Monitoring Networks T2 - 24th IEEE International Conference on Electronics, Circuits and Systems (ICECS), 5-8 Dec. 2017, Batumi, Georgia N2 - A sensor technology for tracking soil-moisture in agricultural fields is presented. A linear measurement method was developed to satisfy the need for cheap sensors with wide range of capacitance change such as factor 30. A combined wired and wireless network transmits data to a server. Various battery aspects are compared with respect to use in agriculture. Y1 - 2017 U6 - https://doi.org/10.1109/ICECS.2017.8292018 SP - 190 EP - 193 ER - TY - CHAP A1 - Schubert, Martin J. W. T1 - System Contemplations for Precision Irrigation in Agriculture T2 - AIP Conference Proceedings N2 - This communication contemplates political, biological and technical aspects for efficient and profitable irrigation in sustainable agriculture. A standard for irrigation components is proposed. The need for many, and three-dimensionally distributed, soil measurement points is explained, thus enabling the control of humidity in selected layers of earth. Combined wireless and wired data transmission is proposed. Energy harvesting and storage together with mechanical sensor construction are discussed. Y1 - 2017 SN - 9780735414969 U6 - https://doi.org/10.1063/1.4979393 VL - 1828 IS - 1 ER - TY - CHAP A1 - Lee, Wai-Kong A1 - Schubert, Martin J. W. A1 - Ho, Stanley Jian-Qin T1 - Multi-source energy harvesting and storage for floating wireless-sensor-network nodes T2 - 2016 IEEE Industrial Electronics and Applications Conference (IEACon 2016), 20.-22. Nov. 2016, Kota Kinabalu, Malaysia Y1 - 2016 SN - 9781509009268 ER - TY - PAT A1 - Schubert, Martin J. W. A1 - Seign, Stefan T1 - Arrangement for Measuring Capacitance Y1 - 2016 ER - TY - JOUR A1 - Weber, Karsten T1 - Die Macht der Maschinenmoral JF - Schweizer Monat Y1 - 2020 UR - https://schweizermonat.ch/die-macht-der-maschinenmoral/# IS - 1077 - Juni ER - TY - JOUR A1 - Gerhards, Helene A1 - Weber, Karsten A1 - Bittner, Uta A1 - Fangerau, Heiner T1 - Machine Learning Healthcare Applications (ML-HCAs) Are No Stand-Alone Systems but Part of an Ecosystem – A Broader Ethical and Health Technology Assessment Approach is Needed JF - The American Journal of Bioethics - AJOB Y1 - 2020 U6 - https://doi.org/10.1080/15265161.2020.1820104 VL - 20 IS - 11 SP - 46 EP - 48 ER - TY - JOUR A1 - Stadler, Dominik A1 - Hofmann, Matthias J. A1 - Motschmann, Hubert A1 - Shamonin (Chamonine), Mikhail T1 - Automotived system for measuring the surface dilational modulus of liquid-air interfaces JF - Measurement Science and Technology N2 - The surface dilational modulus is a crucial parameter for describing the rheological properties of aqueous surfactant solutions. These properties are important for many technological processes. The present paper describes a fully automated instrument based on the oscillating bubble technique. It works in the frequency range from 1 Hz to 500 Hz, where surfactant exchange dynamics governs the relaxation process. The originality of instrument design is the consistent combination of modern measurement technologies with advanced imaging and signal processing algorithms. Key steps on the way to reliable and precise measurements are the excitation of harmonic oscillation of the bubble, phase sensitive evaluation of the pressure response, adjustment and maintenance of the bubble shape to half sphere geometry for compensation of thermal drifts, contour tracing of the bubbles video images, removal of noise and artefacts within the image for improving the reliability of the measurement, and, in particular, a complex trigger scheme for the measurement of the oscillation amplitude, which may vary with frequency as a result of resonances. The corresponding automation and programming tasks are described in detail. Various programming strategies, such as the use of MATLAB® software and native C++ code are discussed. An advance in the measurement technique is demonstrated by a fully automated measurement. The instrument has the potential to mature into a standard technique in the fields of colloid and interface chemistry and provides a significant extension of the frequency range to established competing techniques and state-of-the-art devices based on the same measurement principle. KW - automated measurements KW - DILATATIONAL PROPERTIES KW - dilational modulus KW - graphical user interfaces KW - image processing KW - MEDIUM FREQUENCY-RANGE KW - OSCILLATING BUBBLE TECHNIQUE KW - RHEOLOGY KW - signal processing KW - STABILITY KW - surface rheology KW - TENSIOMETRY Y1 - 2016 U6 - https://doi.org/10.1088/0957-0233/27/6/065301 VL - 27 IS - 6 PB - IOP Science ER - TY - CHAP A1 - Silberbauer, Theodor A1 - Lindner, Matthias A1 - Schreiner, Rupert T1 - Charakterisierung der dielektrischen Barrierenentladung von Mikroplasmaaktuatoren in Abhängigkeit der Substratdicke T2 - Intelligente Systeme und ihre Komponenten: Forschung und industrielle Anwendung : Fachbeiträge 2. Symposium Elektronik und Systemintegration ESI 2020 Y1 - 2020 UR - https://nbn-resolving.org/urn:nbn:de:bvb:860-opus4-2130 N1 - Die Fachtagung, geplant für den 01. April 2020 an der Hochschule Landshut, wurde aufgrund der Corona-Pandemie abgesagt, die eingereichten Fachbeiträge im Tagungsband 2. Symposium Elektronik und Systemintegration ESI 2020: "Intelligente Systeme und ihre Komponenten: Forschung und industrielle Anwendung" veröffentlicht. Hrsg.: Artem Ivanov, Marc Bicker und Peter Patzelt. Hochschule Landshut, 2020, ISBN 978-3-9818439-4-1. SP - 64 EP - 72 CY - Landshut ER - TY - JOUR A1 - Krysztof, Michał A1 - Miera, Paweł A1 - Urbański, Paweł A1 - Grzebyk, Tomasz A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Integrated silicon electron source for high vacuum microelectromechanical system devices JF - Journal of Vacuum Science & Technology B N2 - The article presents the process of developing a silicon electron source designed for high-vacuum microelectromechanical system (HV MEMS) devices, i.e., MEMS electron microscope and MEMS x-ray source. Technological constraints and issues of such an electron source are explained. The transition from emitters made of carbon nanotubes to emitters made of pure silicon is described. Overall, the final electron source consists of a silicon tip emitter and a silicon gate electrode integrated on the same glass substrate. The source generates an electron beam without any carbon nanotube coverage. It generates a high and stable electron current and works after the final bonding process of an HV MEMS device. KW - Materials Chemistry KW - Electrical and Electronic Engineering KW - Surfaces, Coatings and Films KW - Process Chemistry and Technology KW - Instrumentation KW - Electronic, Optical and Magnetic Materials Y1 - 2024 U6 - https://doi.org/10.1116/6.0003385 SN - 2166-2746 VL - 42 IS - 2 PB - AIP Publishing ER - TY - JOUR A1 - Schreiner, Rupert A1 - Naegele, Peter A1 - Körbl, M. A1 - Groning, A. A1 - Gentner, Jean-Louis A1 - Schweizer, Heinz C. T1 - Monolithically integrated tunable laterally coupled distributed-feedback lasers JF - Photonics Technology Letters N2 - A new method for fabrication of tunable InGaAsP-InP single-mode lasers without epitaxial overgrowth is reported. These devices show the advantage of a considerably simplified fabrication process compared to conventional tunable laser types. The lasers comprise an active Bragg reflector integrated with an uncorrugated separately pumped gain region. By adjusting the current through the Bragg reflector, the wavelength can be tuned between 1590.8 and 1595.2 nm. KW - Tunable circuits and devices KW - Optical coupling KW - Laser tuning KW - Etching KW - Pump lasers KW - Laser feedback KW - Optical device fabrication KW - Distributed feedback devices KW - Gratings KW - Fiber lasers Y1 - 2001 U6 - https://doi.org/10.1109/68.969880 VL - 13 IS - 12 SP - 1277 EP - 1279 PB - IEEE ER - TY - INPR A1 - Pangerl, Jonas A1 - Sukul, Pritam A1 - Rück, Thomas A1 - Fuchs, Patricia A1 - Weigl, Stefan A1 - Miekisch, Wolfram A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - An Inexpensive Uv-Led Photoacoustic Based Real-Time Sensor-System Detecting Exhaled Trace-Acetone N2 - In this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) – providing clinically relevant information about the human health. This is achieved via the development of a CO2-triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis. The new sensor system provided a 3σ detection limit of 6.4 ppbV and an NNEA of 1.1E-9 Wcm-1Hz-0.5. In terms of the performed breath analysis measurements, 12 out of 13 fell within the error margin of the photoacoustic measurement system, demonstrating the reliability of the measurements in the field. KW - photoacoustic spectroscopy KW - real-time mass-spectrometry KW - breath analysis KW - acetone KW - UV-LED Y1 - 2024 U6 - https://doi.org/10.2139/ssrn.4724198 N1 - Der Aufsatz wurde peer-reviewed unter folgender DOI veröffentlicht: https://doi.org/10.1016/j.pacs.2024.100604 PB - Elsevier ER - TY - CHAP A1 - Buchner, Philipp A1 - Kaiser, Alexander A1 - Hausladen, Matthias A1 - Bartl, Mathias A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Silicon Nanowire Field Emitters with Integrated Extraction Gates Using Benzocyclobutene as an Insulator T2 - 37th International Vacuum Nanoelectronics Conference (IVNC), 15-19 July 2024, Brno, Czech Republic N2 - We are continuously improving the performance of our field emission electron sources. In this work a geometrically optimized design of electron sources with silicon nanowire field emitters on pillars was fabricated. This new design increased the packing density of the emitters by using a hexagonal arrangement of the pillars and a pillar spacing of 40 µm. Benzocyclobutene was used as the insulator material for an integrated (Cr/Ni) extraction gate. A modified fabrication process for the field emitters further improved reproducibility and reliability. An emission current of about 0.4 mA was measured for 30 minutes at an extraction voltage of 250 V and an anode voltage of 500 V. Electron transmission through the gate reached almost 100%. Y1 - 2024 U6 - https://doi.org/10.1109/IVNC63480.2024.10652314 SP - 1 EP - 2 PB - IEEE ER - TY - JOUR A1 - Berndt, Dominik A1 - Muggli, Josef A1 - Heckel, Robert A1 - Rahiman, Mohd Fuad A1 - Lindner, Matthias A1 - Heinrich, Stephan A1 - Plöchinger, Heinz A1 - Schreiner, Rupert T1 - A Robust Miniaturized Gas Sensor for H₂ and CO₂ Detection Based on the 3ω Method JF - Sensors N2 - Gas concentration monitoring is essential in industrial or life science areas in order to address safety-relevant or process-related questions. Many of the sensors used in this context are based on the principle of thermal conductivity. The 3ω-method is a very accurate method to determine the thermal properties of materials. It has its origin in the thermal characterization of thin solid films. To date, there have been very few scientific investigations using this method to determine the thermal properties of gases and to apply it to gas measurement technology. In this article, we use two exemplary gases (H2 and CO2) for a systematical investigation of this method in the context of gas analysis. To perform our experiments, we use a robust, reliable sensing element that is already well established in vacuum measurement technology. This helix-shaped thin wire of tungsten exhibits high robustness against chemical and mechanical influences. Our setup features a compact measurement environment, where sensor operation and data acquisition are integrated into a single device. The experimental results show a good agreement with a simplified analytical model and FEM simulations. The sensor exhibits a lower detection limit of 0.62% in the case of CO2, and only 0.062% in case the of H2 at an excitation frequency of 1 Hz. This is one of the lowest values reported in literature for thermal conductivity H2 sensors. KW - 3ω-method KW - CO2 sensor KW - H2 sensor KW - thermal gas sensor Y1 - 2022 U6 - https://doi.org/10.3390/s22020485 N1 - Corresponding author: Dominik J. Berndt VL - 22 IS - 2 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Monkman, Gareth J. A1 - Sindersberger, Dirk A1 - Prem, Nina A1 - Szecsey, Tamara T1 - Smart Stiction JF - Robotics & Automation Engineering Journal N2 - Soft robotics could loosely be described as the engineering science of expanded dexterity through controllable flexibility. The exploitation of controllable compliance through the judicious choice of soft flexible members, as opposed to a finite number of rigid kinematic joints, can result in greater dexterity without compromising simplicity. One example is the replacement of segmented mechanical legs with simple compliant material eruciform prolegs. To achieve this in robotics, without introducing additional mechanical joints, mobile surfaces with switchable coefficients of friction is essential. This paper explains how, using silicone based smart materials, the rapid alternation between kinematic and static friction (stiction) may be achieved. Y1 - 2019 U6 - https://doi.org/10.19080/RAEJ.2019.04.555641 N1 - Corresponding author: Gareth J. Monkman VL - 4 IS - 4 PB - Juniper Publishers ER - TY - JOUR A1 - Schreiner, Rupert A1 - Körbl, M. A1 - Gräbeldinger, H. A1 - Gentner, Jean-Louis A1 - Schweizer, H. T1 - Laterally gain-coupled 1.57 [micro sign]m DFB lasers with chromium surface grating and self-aligned Ti/Pt/Au ohmic contact JF - Electronics Letters N2 - A simple method for fabricating gain coupled DFB lasers with lateral surface chromium Bragg gratings and self-aligned low capacitance ohmic contacts is reported. These InGaAsP/InP lasers show monomode emission with a sidemode suppression ratio of 40 dB. For 243 µm long devices a continuous wave threshold current of 17 mA was measured at room temperature. KW - Bragg gratings KW - platinum KW - chromium KW - ohmic contacts KW - titanium KW - distributed feedback lasers KW - gold Y1 - 2000 U6 - https://doi.org/10.1049/el:20000500 SN - 0013-5194 VL - 36 IS - 7 SP - 636 EP - 637 PB - The Institution of Engineering and Technology, IET ER - TY - JOUR A1 - Rück, Thomas A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - NO2 trace gas monitoring in air using off-beam quartz enhanced photoacoustic spectroscopy (QEPAS) and interference studies towards CO2, H2O and acoustic noise JF - Sensors and Actuators B: Chemical N2 - We present the development and characterization as well as comprehensive interference studies of a photoacoustic NO2 trace gas detection system. The system is based on an off-beam quartz enhanced photoacoustic scheme (off-beam QEPAS) and signal generation was initiated by amplitude modulating a low-cost diode laser emitting at 450 nm. The QEPAS sensor element features double-resonant amplification, still it is only ∼ 5 × 5 × 2.5 mm in size. The individual and combined resonance characteristics were investigated and specified to 52 dB amplification, adding up 15 dB acoustic- and 37 dB mechanical-resonance amplification. The linearity of the photoacoustic signal dependency on the analyte concentration was verified from 200 ppbV to 100 ppmV NO2 in synthetic air. The detection limit (3σ) was determined to 1.8 ppbV using a lock-in time constant of 10 s and an averaging time of 20 s. The normalized noise equivalent absorption coefficient was specified to 2.5·10−8 W cm−1 Hz−0.5. The stability of the signal was investigated over time and a slight drift by 1‰ was observed after 30 min without temperature stabilizing the photoacoustic cell (PAC). Noise analysis was performed by means of Allan deviation and the inverse dependency of response time and precision of the system on the lock-in time constant was outlined. We performed interference analyses towards N2, O2, CO2, H2O and acoustic noise, respectively. Although neither spectral interferences nor losses due to slow NO2 VT-relaxation were observed, O2 was identified to cause a 15% signal drop due to VVNO2-O2-relaxation. Changing H2O concentrations were found to cause acoustic detuning, which cannot be compensated by adjusting the frequency of modulation, because of the double-resonant feature of the PAC. However, alternative approaches of compensation were discussed. Finally, we carried out heavy traffic noise simulations and determined the QEPAS setup to be 46 times less susceptible towards ambient noise compared to standard microphone-based photoacoustic setups. Y1 - 2018 U6 - https://doi.org/10.1016/j.snb.2017.09.039 VL - 255 IS - Part 3, February SP - 2462 EP - 2471 PB - Elsevier ER - TY - JOUR A1 - Rück, Thomas A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - Development and characterization of a laboratory setup for photoacoustic NO2 determination based on the excitation of electronic 2B2 and 2B1 states using a low-cost semiconductor laser JF - Sensors and Actuators A: Physical N2 - This work gives a detailed characterization of a laboratory setup for photoacoustic NO2 trace gas detection at the ppb level. The signal generation is based on the excitation of electronic 2B2 and 2B1 states using a low-cost semiconductor laser emitting at 450 nm. An acoustic resonator was used for signal amplification and the modulation frequency of the laser was determined to 3395 Hz in order to gain maximum signal amplification. The quality of resonant amplification was determined to 7.9. The gas samples were NO2 calibration gases diluted with pure nitrogen. The signal-to-noise ratio (SNR) dependency on the flow rate Q and the lock-in time constant τLIA was investigated, respectively, and the optimum values were specified to Q = 500 mL/min and τLIA = 2 s. In case of ambient noise, increasing τLIA to 10 s was evaluated as sufficient for SNR preservation. The noise level was measured in the absence of NO2 and it was determined to be composed of 51% electronic noise and 49% gas flow noise. With the analyte concentration ranging from 300 ppbV to 100 ppmV, the linear dependency of the photoacoustic amplitude on the NO2 concentration was specified, the sensitivity was determined to 110 μV/ppmV and the maximum measurement error was calculated to ±0.8%. The detection limit was determined to 2.0 ppbV. Furthermore, the stability of the signal was investigated and a maximum drift of ±1% was observed within a measuring period of 30 min. The response time τ90 was specified to 58 s. All results considered, this photoacoustic measuring system, which is based on low-cost signal generation and detection units, provides an excellent basis in view of developing a portable device for photoacoustic trace gas detection. Y1 - 2017 U6 - https://doi.org/10.1016/j.sna.2017.03.024 VL - 258 SP - 193 EP - 200 PB - Elsevier CY - Amsterdam, Niederlande ER - TY - JOUR A1 - Rück, Thomas A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - Low-cost photoacoustic NO2 trace gas monitoring at the pptV-level JF - Sensors and Actuators A: Physical N2 - We present the development and the characterization of a photoacoustic NO2 trace gas detection system. The system is based on the implementation of low-cost components, i.e. a mass-produced blue diode laser and a standard MEMS microphone which is commonly built into smartphones, for example. An optimized cell design was realized by means of 3D printing. The linearity of the photoacoustic signal dependency on the analyte concentration was verified from 200 ppbV to 100 ppmV NO2. The detection limit (1σ) was determined to 33 pptV and the normalized noise equivalent absorption coefficient was calculated to 7.0 ∙ 10−10 W cm−1 Hz−1/2. The dynamic range of the system was verified to be linear over three magnitudes of order and the sensitivity was calculated to 814 μV/ppmV. The system was characterized in view of optimal operating parameters, i.e. lock-in time constant τLIA and total mass flow rate, optical performance and signal stability. The mass flow dependend response time of the system was specified to 19 s and an idealized step response to a quasi-Heaviside step function was quantified as a function of τLIA. The quality factor of acoustic resonance was determined to 21.9 and an empirical expression regarding acoustic node shifting is provided. The expression takes into account the radius of the resonator pipe and the radius of the hole, which was drilled into the pipe for microphone coupling. Furthermore, we studied the cross-sensitivity of the photoacoustic signal towards H2O and CO2, respectively. Y1 - 2017 U6 - https://doi.org/10.1016/j.sna.2017.06.036 VL - 263 SP - 501 EP - 509 PB - Elsevier CY - Amsterdam, Niederlande ER - TY - GEN A1 - Weigl, Stefan A1 - Matysik, Frank-Michael A1 - Bierl, Rudolf T1 - Development of a sensor system for analysis of human breath exhale T2 - BayWISS Herbstakademie 2018, Plankstetten N2 - Atemgasanalyse ist ein junges und vielversprechendes Feld im Bereich der diagnostischen Medizin. Der Ansatz verspricht einfach zugängliche und leicht wiederholbare Probennahme die zum einen non-invasiv ist und zugleich Rückschlüsse auf Vorgänge im menschlichen Körper und bspw. dessen Gesundheitszustand zulässt. Seit Ende des 20. Jahrhunderts gibt es Massenspektrometer die es ermöglicht haben mehrere Tausend verschiedene Stoffe in der Ausatemluft nachzuweisen. Diese Technologien verbessern sich stetig und ermöglichen es die Vorgänge und Zusammenhänge zwischen Zusammensetzung der Ausatemluft und systemischen Prozessen besser zu verstehen. Die bei Studien mit Massenspektrometern ermittelten Biomarker, deren qualitative und quantitative Detektion Gesundheitsdiagnosen ermöglichen, haben aber noch nicht den Weg in den klinischen Alltag gefunden. Das Problem sind meistens die hohen Anschaffungskosten, komplizierte Datenauswertung und zumeist geringe Verfügbarkeit und Immobilität dieser Messgeräte. Die photoakustische Spektroskopie ist eine selektive und hochsensitive Messmethode, die es ermöglichen soll den Biomarker „Aceton“, der grundsätzlich die Metabolisierung von Fetten widerspiegelt, schnell und reproduzierbar quantitativ zu detektieren. Dabei müssen Hindernisse wie Querempfindlichkeiten, ausgelöst durch die komplexe Zusammensetzung der Messmatrix Atemgas, bei gleichzeitig kleine Aceton Konzentrationen (200-800 parts-per-billion) überwunden werden. Verschiedene Wellenlängenbereiche mit unterschiedlichen Lichtquellen, akustisch resonante sowie innovative Messzellendesigns und anspruchsvolle Datenauswertung mittels komplexer Algorithmik sind nötig um das Ziel, die Entwicklung eines kompakten, günstigen und zuverlässigen Acetonsensors, zu erreichen. Y1 - 2018 ER - TY - CHAP A1 - Roth, Carina A1 - Hausler, Peter A1 - Bierl, Rudolf T1 - Einbindung eines 2D-Photodetektors in einen hochintegrierten SPR-Imaging-Sensor T2 - 118. Jahrestagung der deutschen Gesellschaft für angewandte Optik (DGaO), 6.-10. Juni 2017, Dresden N2 - Mit der Oberflächenplasmonenresonanzspektroskopie (SPR) können Brechungsindexänderungen eines Analyten von bis zu 10-6 RIU detektiert werden. Das SPR-Imaging bietet heute gegenüber der konventionellen SPR-Analyse die Möglichkeit, mehrere einzelne Messungen parallel durchführen zu können. Mit Hilfe eines zweidimensionalen Sensorchips und einer leistungsfähigen Boardlevelkamera können die Abbildungen des Chips direkt an einen Rechner übertragen und dort verarbeitet werden. Aufgrund unterschiedlicher Winkelstellungen und der Geometrie des Aufbaus entstehen Stauchungen und Streckungen des abgebildeten Sensorchips, die mit verschiedenen Ansätzen aus der Bildverarbeitung ausgeglichen werden, um die Bilder miteinander vergleichen zu können. Zudem wird die Güte der Referenz- und Messbereiche des Chips bestimmt. Diese Algorithmen sind nur möglich aufgrund der heutigen, leistungsfähigen Rechner und der immer größer werdenden Durchsatzraten der Kameras. Dabei kommt in dieser Anwendung der relativ neue Kamerastandard USB3 Vision zum Einsatz. Dieser zeichnet sich zusätzlich durch das Plug and Play und seinen Standardstecker, der an (fast) jedem Rechner vorhanden ist, aus. KW - Bildverarbeitung KW - Messtechnik KW - Optische Informationsverarbeitung Y1 - 2017 ER - TY - CHAP A1 - Zhou, Qi A1 - Landgraf, Ferdinand A1 - Rück, Thomas A1 - Bierl, Rudolf T1 - Resonance frequency tuning and process design of a micromechanical capacitive cantilever in a photoacoustic trace-gas sensing device T2 - 7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, München N2 - Photoacoustic spectroscopy is an efficient method to detect the concentration of trace gases with following advantages: short response time, high sensitivity, continuous and real-time monitoring and the option of miniaturization without the need of complex mirror-based multi-pass cell designs. A micromechanical cantilever is used as a key component in a two-part "Cantilever-Resonator" system that detects the weak photoacoustic signal. The resonance frequency of cantilever needs to be tuned to match the resonance frequency of resonator in order to achieve the maximum vibration amplitude of the "Cantilever-Resonator" system. This paper reports a post-fabrication method to tune the resonance frequency of cantilevers via focused ion beam (FIB) and a capacitive solution for the cantilever to transform the acoustic signal to electrical signal. Y1 - 2017 SN - 978-3-8007-4491-6 PB - VDE-Verlag CY - Berlin ER - TY - JOUR A1 - van der Weerd, Bastiaan A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - Trends in Electrochemical Sensing of Blood Gases JF - Bioanalytical Reviews N2 - The monitoring of partial pressures of the blood gases carbon dioxide (pCO2) and oxygen (pO2) is of great importance in clinical diagnostics. The measure of pCO2 and pO2 provides essential information about the patient’s metabolism, gas exchange, ventilation, and acid–base homeostasis. The conventional electrochemical methods for clinical blood gas analysis are based on the potentiometric Severinghaus sensor for carbon dioxide and the amperometric Clark sensor for oxygen. These techniques are well established and are only shortly discussed in this overview. However, in recent years a variety of modifications of these classical sensor concepts and new approaches of electrochemical sensing of pCO2 and pO2 have been introduced. This review summarizes recent developments in this field and discusses the potential for future applications in clinical blood gas analysis. KW - Blood gas analysis KW - Noninvasive blood gas sensor KW - Electrochemical sensor KW - Clinical analysis Y1 - 2016 U6 - https://doi.org/10.1007/11663_2016_1 VL - 6 SP - 263 EP - 280 PB - Springer CY - Berlin ER - TY - CHAP A1 - Rück, Thomas A1 - Läpple, I. A1 - Bierl, Rudolf T1 - Photoakustische Spurengasanalytik von NO2 im ppt-Bereich (10^-12) bei Verwendung kostengünstiger Einzelkomponenten T2 - 7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, München KW - Elektroniksystem KW - Industrie 4.0 KW - Mikrosystemtechnik KW - Mikrofluidik KW - Mikroaktorik Y1 - 2017 SN - 978-3-8007-4491-6 PB - VDE-Verlag CY - Berlin ER - TY - JOUR A1 - Zagler, Andreas A1 - Landgraf, Ferdinand A1 - Rück, Thomas A1 - Bierl, Rudolf T1 - Entwicklung eines mikromechanischen kapazitiven Schalldetektors im resonanten Betrieb für die photoakustische Spurengasanalyse JF - 7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, München Y1 - 2017 PB - VDE-Verlag CY - Berlin ER - TY - CHAP A1 - Gaida, Peter A1 - Weigl, Stefan A1 - Rück, Thomas A1 - Bierl, Rudolf T1 - Portable photoakustische Messeinheit zur NO2 Detektion im Spurenbereich T2 - 7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, München Y1 - 2017 SN - 978-3-8007-4491-6 PB - VDE-Verlag CY - Berlin ER - TY - CHAP A1 - Fischer, Johannes T1 - Miniaturisierter plasmonischer Sensor für das Monitoring von Weichmachern in Gewässerproben T2 - 7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, München Y1 - 2017 SN - 978-3-8007-4491-6 PB - VDE-Verlag CY - Berlin ER - TY - GEN A1 - Hausler, Peter A1 - Roth, Carina A1 - Vitzthumecker, Thomas A1 - Fischer, Johannes A1 - Bierl, Rudolf T1 - Motionless SPR-angle scan with a miniaturized device T2 - Europtrode XIV, Naples, 25-28 March 2018 Y1 - 2018 ER - TY - CHAP A1 - Weigl, Stefan A1 - Gaida, Peter A1 - Rück, Thomas A1 - Bierl, Rudolf T1 - Portable Measurement Unit for NO2 Trace Gas Detection T2 - PHOTOPTICS 2018, 6th International Conference on Photonics, Optics and Laser Technology, 25 - 27 January 2018, Funchal Madeira Y1 - 2018 ER - TY - RPRT A1 - Unger, J. A1 - Rück, Thomas A1 - Landgraf, Ferdinand A1 - Bierl, Rudolf T1 - Herstellung und Analyse der Resonanzfrequenz eines MEMS Cantilever für das CEPAS Verfahren N2 - Diese Abhandlung beschreibt das Konzept eines mikroeletromechanischen Systems (MEMS), das im Messverfahren der cantilever enhanced photoacoustic spectroscopy (CEPAS) Verwendung finden soll. Es wird die Herstellung eines einseitig eingespannten Biegebalkens aus Silizium mittels deep reactiv ion etching (DRIE) beschrieben. Des Weiteren wird die Resonanzfrequenz dieses Cantilevers mit Hilfe Laservibrometertechnik untersucht. Die resultierenden resonanten Schwingungen 0.Ordnung werden mit den Ergebnissen einer vereinfachten theoretischen Näherung verglichen. Die Messergebnisse stehen in gutem Zusammenhang mit den theoretischen Werten. Solche Cantilever, die aus silicon on insula tor (SOI) Wafer angefertigt wurden, weisen bei einer Zielfrequenz ein mittlere Abweichung von Δf = 118±26Hz (bzw.Δf =0,76±0,17%) auf. Y1 - 2015 ER - TY - CHAP A1 - Holler, Sven A1 - Hausler, Peter A1 - Roth, Carina A1 - Bierl, Rudolf T1 - Gestapelte Au-Al-Au und Au-Ag-Au Schichten als aktive Schichten für die Oberflächenplasmonenresonanzspektroskopie T2 - 5. Landshuter Symposium Mikrosystemtechnik, März 2016 Y1 - 2016 SN - 978-3-9812696-9-7 SP - 192 EP - 198 PB - Fachhochschule Landshut CY - Landshut ER - TY - CHAP A1 - Roth, Carina A1 - Hausler, Peter A1 - Bierl, Rudolf T1 - Einbindung eines CMOS-Detektors in einen hochintegrierten SPR-Sensor T2 - 5. Landshuter Symposium Mikrosystemtechnik, März 2016 Y1 - 2016 SN - 78-3-9812696-9-7 SP - 200 EP - 205 PB - Fachhochschule Landshut CY - Landshut ER - TY - CHAP A1 - Jobst, Simon A1 - Bierl, Rudolf T1 - A Comparison of Correlation and Zero-Crossing Based Techniques in Ultrasonic Measurement T2 - 10th International Symposium on Applied Reconfigurable Computing (ARC'2014), Vilamoura, Algarve, Portugal, 14 - 16 April, 2014 N2 - Ultrasound measurement technology has advancedin previous decades due to positive developments in computing power and lower cost for the necessary hardware. Correlation-based processing can be advantageous for high-accuracy measurements, especially in noisy environments. Higher computational load makes correlation less attractive for industrialapplications, though, favouring traditional processing techniques. A platform for comparing various processing techniques hasbeen developed. It was found that both zero-crossing detectionas well as correlation can achieve very high accuracy over a hightemperature range but that correlation-based processing can lead to a significant precision bias depending on system bandwidth. Y1 - 2014 ER - TY - CHAP A1 - Rück, Thomas A1 - Landgraf, Ferdinand A1 - Läpple, I. A1 - Unger, J. A1 - Matysik, Frank-Michael A1 - Bierl, Rudolf T1 - Specification of an improved photoacoustic setup for high-sensitive, low-cost NO2 trace gas detection T2 - 18th International Conference on Photoacoustic and Photothermal Phenomena (ICPPP18), 2015, September 6-10, Novi Sad, Serbia Y1 - 2015 ER - TY - CHAP A1 - van der Weerd, Bastiaan A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - A Conductivity Probe for the Determination of Carbon Dioxide Tension at the Oxygenator Exhaust Outlet during Extracorporeal Membrane Oxygenation (ECMO) T2 - analytica Conference 2014, 1. bis 4. April, München Y1 - 2014 ER - TY - CHAP A1 - van der Weerd, Bastiaan A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - A Conductivity Probe for the Determination of Carbon Dioxide Tension at the Oxygenator Exhaust Outlet during Extracorporeal Membrane Oxygenation (ECMO) T2 - Electrochemistry 2014, September 22 - 24, Mainz Y1 - 2014 ER - TY - CHAP A1 - van der Weerd, Bastiaan A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - A Planar Conductivity Probe for CO2 Determination at the Oxygenator Outlet T2 - Doktorandenseminar GDCh Prozessanalytik 2014, Berlin Y1 - 2014 ER - TY - JOUR A1 - Kurzweil, Peter A1 - Schottenbauer, Josef A1 - Schell, Christian T1 - Past, Present and Future of Electrochemical Capacitors: Pseudocapacitance, Aging Mechanisms and Service Life Estimation JF - Journal of Energy Storage N2 - The capacitance values printed on capacitor housings do not reflect the actual capacitance available for any technical application. The complex properties of the pseudocapacitance and the aging behavior of practical supercapacitors are reviewed with regard to the state-of-the-art and the latest findings. The long-term stability of various electrolyte systems and carbon materials is critically examined under phenomenological aspects that reflect the typical fault pattern of supercapacitors. Electrolyte resistance and voltammetric capacitance are reliable aging indicators. High temperatures have a greater impact on service life than high voltages, and overvoltages are worse than high currents. The anode more than the cathode suffers from a loss of pore volume, increase of nitrogen and fluorine compounds, and the unstable adhesive layer between active carbon and aluminum. Unwanted material changes and chemical reactions in the supercapacitor reflect the influence of water over several years in the life test. Credible reaction pathways are identified for the known aging processes. Fundamentals and materials are reviewed in a separate part.** KW - Electrochemical double-layer capacitors KW - Supercapacitor KW - Capacitance KW - Pseudocapacitance KW - Aging mechanisms KW - Carbon degradation KW - State-of-health Review KW - Review Y1 - 2020 U6 - https://doi.org/10.1016/j.est.2021.102311 VL - 35 IS - March PB - Elsevier ER - TY - JOUR A1 - Steininger, Peter A1 - Gaderer, Matthias A1 - Dawoud, Belal A1 - Gaderer, Matthias T1 - Experimental and numerical study on the solar gain and heat loss of typical existing and refurbished German buildings JF - iCRBE Procedia N2 - This communication introduces an experimental setup for investigating the effect of solar radiation on the reduction of transmission heat losses and the steady state thermal conductance of uninsulated and insulated multi-layer wall samples. The setup consists of two adjacent climatic chambers, which share a common wall, in which the multi-layer wall samples are mounted. A solar simulator is applied within the outdoor air climatic chamber, whose radiation spectrum and radiation intensity are approximately equivalent to those of the sun. The first tests have been carried out on a wall sample with a typical structure of existing buildings from the year 1930 in Germany. In addition, a high-performance insulating plaster layer has been applied on a basic test sample (with existing building structure) to replicate and assess the refurbished scenario. Furthermore, a numerical investigation on the transient heat transfer process is carried out by using the simulation software COMSOL Multiphysics®. The experimental results of both uninsulated and insulated wall samples are validated against 1D and 3D models. As seen, the uninsulated wall, whose thermal conductance was experimentally determined to be equal to 1.79 W/(m²K), absorbs a heat flux of 208 W/m² through its external wall surface over a period of 8 hours. A fraction of 9.8 % of the absorbed heat arrives as a gain on the internal wall and reduces the transmission heat losses by 11.7 % over a period of 55 hours. On the other hand, the thermal conductivity of the insulation layer of the refurbished wall sample with micro hollow glass spheres was estimated by a parameter estimation procedure using the 3D model and the obtained experimental data. Using the estimated thermal conductivity, a thermal conductance of 0.42 W/(m²K) has been obtained for the refurbished wall sample. Y1 - 2020 UR - https://www.scilit.net/article/e45ed49630736c2ed82cd848e55bb69c?action=show-references U6 - https://doi.org/10.32438/icrbe.202035 VL - 1 IS - 1 SP - 75 EP - 93 PB - Weentech ER - TY - CHAP A1 - Sindersberger, Dirk A1 - Prem, Nina A1 - Monkman, Gareth J. A1 - Zimmermann, Klaus ED - Schlaak, Helmut T1 - Self-Sensing Electroadhesive Polymer Gripper with Magnetically Controllable Surface Geometry T2 - Actuator 2021, International Conference and Exhibition on New Actuator Systems and Applications: GMM conference, February 17-19, 2021, online event N2 - Compared to conventional end effectors, electro-adhesive grippers enable the handling of sensitive, soft or air-permeable materials [1]. The prehension force is based on a strong electric field generated by electrodes resulting in a polarisation of the dielectric and the generation of mirror charges in the workpiece. When the electrode supply voltage is deactivated, the electric field drops,but an electrostatic field remains due to remanent polarisation of the dielectric. The residual charge on the gripper surface reduces only slowly and in combination with other influencing factors can prevent the workpieces from being ejected temporarily or completely. In this work a solution to this problem is presented by means of gripper surface deforming caused by the applicat ion of a magnetic field to a magneto- active polymer (MAP) actuator. The in-creased distance between the workpiece and the dielectric enables precise and controlled ejection. In addition to compliance and deformability, the employment of soft smart materials enables the integration of self-sens-ing mechanisms for the measurement of surface deformation. The embedding of electrically conductive flexible electrodes within the soft silicone dielectric sup port such movements and serves as the n ecessary electrodes for electroadhesion. Since the implementation of the end effectoris based entirely on soft materials, the self-sensing magnetically controllable electroadhesive gripper (SMEG) can be produced in a shape deposition manufacturing (SDM) process [2], [3] and is highly applicable to the field of soft robotics. Y1 - 2021 SN - 9783800754540 U6 - https://doi.org/10.1002/macp.201800222 SP - 318 EP - 320 PB - VDE VERLAG CY - Berlin; Offenbach ER - TY - JOUR A1 - Yeap, Kim Ho A1 - Meister, Tobias A1 - Oh, Zi Xin A1 - Nisar, Humaira T1 - Circuit Modelling Methodology for Dual-band Planar Antennas JF - APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL N2 - This paper presents a simple and systematic approach to determine the equivalent frequency-independent circuit model for a dual-band planar antenna. The Foster Canonical network synthesis technique with two RLC tanks has been employed to generate the two resonant bands of the antenna. The transfer function model is subsequently refined using a data fitting algorithm (viz the Nelder-Mead simplex algorithm). Parametric adjustments are performed at the final stage in order to further improve the accuracy of the final parameters. KW - COMPACT KW - Data-fitting algorithm KW - equivalent circuit KW - Foster canonical network KW - PATCH KW - planar antenna KW - resonant bands KW - SHAPED ANTENNA Y1 - 2021 U6 - https://doi.org/10.47037/2021.ACES.J.360822 VL - 36 IS - 8 SP - 1112 EP - 1115 PB - APPLIED COMPUTATIONAL ELECTROMAGNETICS SOC ER - TY - CHAP A1 - Schorr, Philipp A1 - Böhm, Valter A1 - Zentner, Lena A1 - Zimmermann, Klaus ED - Gusikhin, Oleg ED - Madani, Kurosh T1 - Design of a Vibration Driven Motion System Based on a Multistable Tensegrity Structure T2 - ICINCO 2018: proceedings of the 15th International Conference on Informatics in Control, Automation and Robotics, Porto, Portugal, July 29-31, 2018 N2 - In this paper a novel approach to realize a uniaxial bidirectional vibration driven motion system with controllable direction of motion is investigated. The considered motion system bases on a tensegrity structure with multiple stable equilibrium configurations. The structure is in contact with a horizontal plane due to gravity and the actuation is realized by the harmonic change of the length of a selected member. Beside varying the actuation parameters, the direction of motion can be controlled by changing the equilibrium configuration of the tensegrity structure. In this paper the topology of the tensegrity structure and the parameter values are chosen appropriately to provide two symmetric equilibrium configurations. A change of the equilibrium state yields a novel configuration of the entire motion system which is symmetric to the original state. Utilizing the symmetry of the system the same actuation yields an opposite motion. This approach represents a reliable opportunity to control the direction of motion by changing the equilibrium state for constant actuation parameters. This paper focuses on the parameter selection and the design of the actuation of the vibration driven motion system. The working principle of the vibration driven motion system is verified by numerical simulations. This contribution represents the theoretical investigation for the further development of a prototype. KW - Compliant tensegrity structure KW - Vibration driven motion multistability Y1 - 2020 SN - 978-3-030-31992-2 U6 - https://doi.org/10.1007/978-3-030-31993-9_14 VL - 613 SP - 302 EP - 317 PB - Springer CY - Cham ER - TY - CHAP A1 - Thomeczek, Ludwig A1 - Attenberger, Andreas A1 - Kolb, Johannes A1 - Matoušek, Vaclav A1 - Mottok, Jürgen ED - Trinitis, Carsten ED - Pionteck, Thilo T1 - Measuring Safety Critical Latency Sources using Linux Kernel eBPF Tracing T2 - ARCS 2019: 32nd International Conference on Architecture of Computing Systems : workshop proceedings, May 20- 21, 2019, Technical University of Denmark, Copenhagen, Denmark Y1 - 2019 UR - https://ieeexplore.ieee.org/abstract/document/8836200 SN - 978-3-8007-4957-7 PB - VDE VERLAG GMBH CY - Berlin ER - TY - JOUR A1 - Baumer, Johannes A1 - Shamonin (Chamonine), Mikhail T1 - Abstandsensorsystem basierend auf dem Prinzip der optischen Reflektion für Anwendungen im Bereich Weiße Ware: Intensitätsreferenzierung und Linearisierung des Ausgnagssignals JF - TM - Technisches Messen N2 - Ein auf optischer Reflektion basierendes Abstandssensorsystem für die „Weiße Ware“ wird hier vorgestellt. Die technische Lösung greift auf ein allseits bekanntes Intensitätsreferenzierungsprinzip – die optische Brücke – zurück. Der Einfluss der Umgebungstemperatur kann kompensiert werden. Störeffekte wie alterungsbedingte Drift der optischen Elemente oder Systemvariationen der Empfindlichkeit verursacht durch die Streuung der einzelnen Komponenten können erfolgreich gehandhabt werden. Ein Algorithmus zur Ausgangslinearisierung und dessen Optimierung in Hinblick auf einen kostengünstigen Mikrokontroller wird beschrieben. Zum Schluss wird ein Prototyp eines Fertigungsautomaten, der zur Herstellung dieses Sensors dient, und dessen grundlegende Funktion vorgestellt. A reflective optical sensor system for distance measurements in white-goods applications is presented. The technical solution implements a well-known intensity referencing principle - the optical bridge - in a low-cost design. The influence of the ambient temperature can be compensated for. The spurious effects such as slow output drift caused by aging of optical components or the variation of the system sensitivity due to the parameter spreading of system components can be successfully overcome as well. An algorithm for linearizing the system response is described and optimized for a low-cost microcontroller. Finally, a prototype of an assembly line, which is used for producing this sensor system, is described and its basic funcionallity is demonstrated. T2 - Optical-reflection-based distance sensor system for white-goods applications: intensity referencing and response linearization KW - Fertigungskonzept KW - Kompensation von Störeffekten KW - Kostengünstiger Abstandssensor KW - Liearisierung der Sensorantwort KW - optische Reflektion Y1 - 2014 U6 - https://doi.org/10.1515/teme-2014-1014 VL - 81 IS - 2 SP - 62 EP - 69 PB - de Gruyter ER - TY - JOUR A1 - Fuersattel, Peter A1 - Plank, Claus A1 - Maier, Andreas A1 - Riess, Christian T1 - Accurate laser scanner to camera calibration with application to range sensor evaluation JF - IPSJ Transactions on Computer Vision and Applications N2 - Multi-modal sensory data plays an important role in many computer vision and robotics tasks. One popular multi-modal pair is cameras and laser scanners. To overlay and jointly use the data from both modalities, it is necessary to calibrate the sensors, i.e., to obtain the spatial relation between the sensors. Computing such a calibration is challenging as both sensors provide quite different data: cameras yield color or brightness information, laser scanners yield 3-D points. However, several laser scanners additionally provide reflectances, which turn out to make calibration to a camera well feasible. To this end, we first estimate a rough alignment of the coordinate systems of both modalities. Then, we use the laser scanner reflectances to compute a virtual image of the scene. Stereo calibration on the virtual image and the camera image are then used to compute a refined, high-accuracy calibration. It is encouraging that the accuracies in our experiments are comparable to camera-camera stereo setups and outperform another of other target-based calibration approach. This shows that the proposed algorithm reliably integrates the point cloud with the intensity image. As an example application, we use the calibration results to obtain ground-truth distance images for range cameras. Furthermore, we utilize this data to investigate the accuracy of the Microsoft Kinect V2 time-of-flight and the Intel RealSense R200 structured light camera. KW - Kinect V2 KW - Laser scanner KW - Range camera KW - RealSense R200 Y1 - 2017 U6 - https://doi.org/10.1186/s41074-017-0032-5 VL - 9 IS - 1 PB - Springer Nature ER - TY - JOUR A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Dams, Florian T1 - Compact and Energy-Efficient Field Emission Cathodes for Sensor Applications JF - Advanced Materials Research N2 - We report on miniaturized silicon field emitter arrays for the application in compact and energy-saving vacuum-microelectronic devices, e.g. sensors or x-ray tubes. Since standard silicon semiconductor technology has been used for the fabrication, they may be easily integrated with other silicon based circuits and devices on the same chip. The silicon tip geometry and the operating conditions were optimized in order to obtain highly uniform and stable electron field emission from large area cathode arrays. A series of uniform hexagonal tip arrays containing each 547 tips were fabricated and characterized. The electron emission properties of both individual tips as well as of complete emitter arrays were investigated. A saturation level in the voltage-current characteristics was found, which can be explained by the limitation of the supply of electrons due to the p-type silicon wafer material. When operating the arrays in the current saturation regime at an emission current of ~ 1 nA per tip, a highly stable and low noise emission can be observed. KW - field emission KW - Si-Tip Cathodes KW - Vacuum Sensors Y1 - 2014 U6 - https://doi.org/10.4028/www.scientific.net/amr.1024.372 VL - 1024 SP - 372 EP - 375 PB - Scientific.net ER - TY - JOUR A1 - Burdin, Dmitrii A. A1 - Chashin, Dmitri V. A1 - Ekonomov, Nikolai A. A1 - Fetisov, Leonid Y. A1 - Fetisov, Yuri K. A1 - Shamonin (Chamonine), Mikhail T1 - DC magnetic field sensing based on the nonlinear magnetoelectric effect in magnetic heterostructures JF - Journal of physics D: Applied physics N2 - Recently, highly sensitive magnetic field sensors using the magnetoelectric effect in composite ferromagnetic-piezoelectric layered structures have been demonstrated. However, most of the proposed concepts are not useful for measuring dc magnetic fields, because the conductivity of piezoelectric layers results in a strong decline of the sensor's sensitivity at low frequencies. In this paper, a novel functional principle of magnetoelectric sensors for dc magnetic field measurements is described. The sensor employs the nonlinear effect of voltage harmonic generation in a composite magnetoelectric structure under the simultaneous influence of a strong imposed ac magnetic field and a weak dc magnetic field to be measured. This physical effect arises due to the nonlinear dependence of the magnetostriction in the ferromagnetic layer on the magnetic field. A sensor prototype comprising of a piezoelectric fibre transducer sandwiched between two layers of the amorphous ferromagnetic Metglas (R) alloy was fabricated. The specifications regarding the magnetic field range, frequency characteristics, and noise level were studied experimentally. The prototype showed the responsivity of 2.5 V mT(-1) and permitted the measurement of dc magnetic fields in the range of similar to 10 nT to about 0.4 mT. Although sensor operation is based on the nonlinear effect, the sensor response can be made linear with respect to the measured magnetic field in a broad dynamic range extending over 5 orders of magnitude. The underlying physics is explained through a simplified theory for the proposed sensor. The functionality, differences and advantages of the magnetoelectric sensor compare well with fluxgate magnetometers. The ways to enhance the sensor performance are considered. KW - composite KW - magnetic field sensors KW - magnetic heterostructures KW - magnetoelectric effect KW - nonlinear magnetostriction KW - Sensors KW - voltage harmonic generation Y1 - 2016 U6 - https://doi.org/10.1088/0022-3727/49/37/375002 VL - 49 IS - 37 PB - IOP Publishing ER - TY - JOUR A1 - Diermeier, Andreas A1 - Sindersberger, Dirk A1 - Angele, Peter A1 - Kujat, Richard A1 - Monkman, Gareth J. T1 - Sensor system for use with low intensity pulsed ultrasound JF - Sensor review N2 - Purpose Ultrasound is a well-established technology in medical science, though many of the conventional measurement systems (hydrophones and radiation force balances [RFBs]) often lack accuracy and tend to be expensive. This is a significant problem where sensors must be considered to be "disposable" because they inevitably come into contact with biological fluids and expense increases dramatically in cases where a large number of sensors in array form are required. This is inevitably the case where ultrasound is to be used for the in vitro growth stimulation of a large plurality of biological samples in tissue engineering. Traditionally only a single excitation frequency is used (typically 1.5 MHz), but future research demands a larger choice of wavelengths for which a single broadband measurement transducer is desirable. Furthermore, because of implementation conditions there can also be large discrepancies between measurements. The purpose of this paper deals with a very cost-effective alternative to expensive RFBs and hydrophones. Design/methodology/approach Utilization of cost-effective piezoelectric elements as broadband sensors. Findings Very effective results with equivalent (if not better) accuracy than expensive alternatives. Originality/value This paper concentrates on how very cost-effective piezoelectric ultrasound transducers can be implemented as sensors for ultrasound power measurements with accuracy as good, if not better than those achievable using radiation force balances or hydrophones. KW - BALANCE KW - Hydrophone KW - Mesenchymal stem cell KW - Piezoelectric transducer KW - Radiation force balance KW - Sensors KW - therapy KW - Tissue engineering KW - Ultrasound Y1 - 2019 U6 - https://doi.org/10.1108/SR-11-2018-0304 SN - 0260-2288 VL - 39 IS - 6 SP - 828 EP - 834 PB - Emerald ER - TY - CHAP A1 - Hausladen, Matthias A1 - Bomke, Vitali A1 - Buchner, Philipp A1 - Bachmann, Michael A1 - Knapek, Alexandr A1 - Schreiner, Rupert T1 - Influence of Geometrical Arrangements of Si Tip Arrays Fabricated by Laser Micromachining on their Emission Behaviour T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 7/5/2021 - 7/9/2021, Lyon, France N2 - ensely packed emitters on a field emission array lead typically to mutual shielding. Taking biology as a role model for geometric arrangements could be a way to reduce this effect. For comparison, two electron sources, one with a spiral and a second with conventional rectangular (orthogonal) arranged emitters, were fabricated and investigated. Emission currents of 6 µA in the spiral ordered array and 120 µA in the rectangular array were reached with an extraction voltage of 400 V. From a mid-term measurement over 1 h a current stability of ±8.8 % (spiral) respectively ±5.7 % (rectangular) with a mean degradation of -3.0 µA/h (spiral) and -0.12 µA/h (rectangular) could be observed. KW - aperture field KW - emission grid KW - Fabrication KW - laser micromachining KW - parastichy tip arrangements KW - silicon field emission KW - Stability analysis KW - Spirals KW - Field emitter array KW - Voltage measurement Y1 - 2021 SN - 978-1-6654-2589-6 U6 - https://doi.org/10.1109/IVNC52431.2021.9600717 SN - 2380-6311 PB - IEEE CY - Piscataway, N.J. ER - TY - CHAP A1 - Buchner, Philipp A1 - Bomke, Vitali A1 - Hausladen, Matthias A1 - Edler, Simon A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Investigation on the Emission Behaviour of p-doped Silicon Field Emission Arrays with Individually Controllable Single Tips T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 7/5/2021 - 7/9/2021, Lyon, France N2 - Four individually controllable emission tips consisting of <111> p-Type silicon, were structured on a glass substrate by laser ablation. A matching extraction grid was manufactured in the same manner and aligned with the emitters. The resulting samples were characterized in ultra-high vacuum. As expected, the individual currents show a strong saturation and in the saturation region a considerably lower current fluctuation than n-type silicon due to charge carrier depletion. The individual tips behave completely independent behaviour from each other and the overall emission can be deduced from the sum of the currents through the individual tips. Y1 - 2021 SN - 978-1-6654-2589-6 U6 - https://doi.org/10.1109/IVNC52431.2021.9600756 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Hecht, Fabian A1 - Bauereiβ, Florian A1 - Sellmair, Josef A1 - Buchner, Philipp A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Electron Beam Induced Growth of Carbon Nanotips on Tungsten and Silicon Fieldemitters T2 - 2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA N2 - In our experiments we grew electron emitting carbon nanostructures on tungsten tips. Subsequently, we transferred the growth process to pre-structured phosphorus-doped n-type silicon and obtained emitting carbon nanostructures directly grown on silicon. After growth of the nanostructures, the silicon field emitters showed increased emission currents of 76 nA at 1.1 kV (compared to 6 nA under the same conditions before growth). KW - Behavioral sciences KW - Nanostructures KW - Silicon KW - Carbon dioxide KW - Current measurement KW - Electron beams KW - Tungsten Y1 - 2023 SN - 979-8-3503-0143-4 U6 - https://doi.org/10.1109/IVNC57695.2023.10188960 SP - 160 EP - 162 PB - IEEE ER - TY - CHAP A1 - Allaham, Mohammad M. A1 - Buchner, Philipp A1 - Schreiner, Rupert A1 - Knápek, Alexandr T1 - Testing the performance of Murphy-Good plots when applied to current-voltage characteristics of Si field electron emission tips T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France N2 - Murphy-Good plots are the most recent type of the analysis methods in the field electron emission theory, this type of plots has several useful characteristics such as: having the very-nearly straight line to represent the current-voltage characteristics and the absence of the correction factors in the mathematical procedure of the analysis process. In this study, n-type <111> and <100> Si chips containing four individual emitters are used as base emitters and mounted in a diode configuration field emission setup where the experiments are operated in an ultra-high vacuum ( 10-7 Pa). Each chip has four individual controllable emitters with 5 µm distance between the Si tips and the same material grid. Laser micromachining and subsequent wet chemical etching technique is used to structure and polish the tips. Murphy-Good plots are used to study the behavior of the Si individual tips and compare the results with the array current by extracting the field emission characterization parameters of the emitters. KW - characterization parameter KW - Current-voltage characteristics KW - electron emission KW - electron source KW - Limiting KW - Micromachining KW - Murphy-Good plot KW - n-type Si chip KW - RESISTANCE KW - safety KW - silicon Y1 - 2021 U6 - https://doi.org/10.1109/IVNC52431.2021.9600690 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Blahníková, Barbora A1 - Müller, D. A1 - Waas, M. A1 - Lechner, Alfred T1 - Multilyzer - microfluidic online measuring system for the analysis of environmentally relevant substances T2 - AMA Conferences 2017 : Proceedings : SENSOR 2017 / Nürnberg 2017-05-30 - 2017-06-01 Y1 - 2017 SN - 978-3-9816876-4-4 U6 - https://doi.org/10.5162/sensor2017/P5.2 SP - 696 EP - 699 PB - AMA Service GmbH CY - Wunstorf ER - TY - JOUR A1 - Melekhov, Evgeny A1 - Penn, Tatjana A1 - Weidauer, Tobias A1 - Abb, Valerius A1 - Kammler, Martin A1 - Lechner, Alfred T1 - Tunable nanopillar array on a quartz-fiber tip for surface enhanced Raman scattering (SERS) detection JF - tm - Technisches Messen N2 - In this work, a simple two-step method to create tunable self-assembled three-dimensional nanostructure array-like nanoantennas directly on the tip of an optical quartz glass fiber is described. The structures are prepared by using dry etching of the fiber tip. For the etching process, gold nanoparticles fabricated by thermal dewetting technique were used as template. The structures are applied as sensors for label-free analysis of organic substances in ppb range, such as drug residues in liquid solutions. The measurements are carried out by a portable Raman device with an exchangeable sensor head utilizing the SERS-effect. This method allows in situ applications. In order to characterize the SERS cells, para-thiocresol and diclofenac sodium are used as model substances. For optimization of the substrate performance, different thicknesses of the dewetting-layer (6, 9, 12 nm), different etching times for formation of the pillars (6, 8, 10 and 12 min), and different thicknesses of SERS-metallization (25, 50, 75 nm) of gold and silver are compared. In order to show the applicability of the structure on the tip of a fiber, measurements from the upper side and from the underside of the substrate on quartz plates are compared. Reproducible SERS enhancement factors up to 10 7 {10^{7}} were achieved. N2 - In dieser Arbeit wird eine zweistufige Methode beschrieben, um einstellbare selbstorganisierte dreidimensionale SERS-aktive Nanostrukturen in Form von Nanosäulen auf der Spitze einer optischen Quarzglasfaser herzustellen. Die Strukturen werden durch trockenchemisches Ätzen der Faserspitze erzeugt. Für den Ätzprozess werden als Maske Goldnanopartikel verwendet, die mittels Thermal Dewetting hergestellt werden. Der Sensor wird für eine markierungsfreie Analyse von organischen Substanzen, wie bspw. Medikamentenrückstände in wässrigen Lösungen, im ppb-Bereich eingesetzt. Die Messungen werden mit einem tragbaren Raman-Gerät mit einem austauschbaren Sensorkopf durchgeführt. Um die SERS-Zellen zu charakterisieren, werden para-Thiocresol und Diclofenac-Natrium als Modellsubstanzen verwendet. Zur Optimierung der Substratleistung werden unterschiedliche Dicken der Dewettinglayer (6, 9, 12 nm), unterschiedliche Ätzzeiten der Nanosäulen (6, 8, 10 und 12 min) und unterschiedliche Schichtdicken der SERS-Metallisierung (25, 50, 75 nm) von Gold und Silber verglichen. Um die Anwendbarkeit der Struktur an der Spitze einer Faser zu zeigen, werden Messungen von der Oberseite und von der Rückseite des Substrats in Form eines Quarzglasplatten verglichen. Diese Struktur liefert einen reproduzierbaren Verstärkungsfaktor von bis zu 107. T2 - Einstellbare Nanosäulenanordnung auf der Spitze einer Quarzglasfaser für oberflächenverstärkte Raman-Spektroskopie (SERS) Y1 - 2022 U6 - https://doi.org/10.1515/teme-2021-0093 VL - 89 IS - 1 SP - 70 EP - 81 PB - de Gruyter ER - TY - CHAP A1 - Blahníková, Barbora A1 - Müller, D. A1 - Waas, M. A1 - Lechner, Alfred T1 - Multilyzer - Mikrofluidisches Echtzeitmesssystem für die Analyse umweltrelevanter Substanzen T2 - 7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, München N2 - Die übermäßige Verwendung von stickstoffbasierten Düngemitteln in der Landwirtschaft stellt eine Gefährdung für die Umwelt und Lebewesen dar. So ist die Analyse von Boden- und Grundwasser zu einem wesentlichen Bestandteil der Nachhaltigkeit und der ökologischen Erhaltung geworden. Dafür bietet der Multilyzer eine passende Lösung. Der Multilyzer ist ein mikrofluidisches Analysesystem zur Bestimmung niedrigster Konzentrationen von Nitrat, Nitrit und Ammonium, die alle wesentliche Bestandteile des Stickstoffkreislaufs sind. Welche bei Übermäßiger Aufnahme im Körper krebserregend wirken und den Sauerstofftransport im Blutkreislauf stören. Der Aufbau ist eine Kombination aus Absorptions- und Fluoreszenzspektroskopie. Der Betrieb mit einer 12 Volt Batterie ermöglicht die Verwendung des Multilyzer-Systems zur Online-Messung im Feld. Somit können sehr kurze Analysezeiten realisiert und der Einfluss von Umwandlungs- bzw. Abbauprozessen vermieden werden. Das gesamte Messsystem wird im Kompetenzzentrum Nanochem an der OTH Regensburg entwickelt, inklusive Fertigungstechnologien, Software- und Hardwaresteuerung. N2 - Excessive use of nitrogen based fertilizers in agriculture represents an environmental hazard. Thus, analysis of soil water and groundwater has become an essential part of sustainability and ecological preservation. On this account, the Multilyzer provides a suitable solution. The Multilyzer is a microfluidic measuring system for the determination of lowest concentrations of nitrate, nitrite and ammonium, which are essential components of the nitrogen cycle. The measurement combines the principles of absorption and fluorescence spectroscopy. As a transportable unit, online measurements can be carried out using a 12 Volts battery power supply. Consequently, the influence of conversion and degradation processes can be avoided. The complete device is developed at the Centre of Excellence Nanochem at OTH Regensburg including fabrication technologies, software and hardware control. T2 - Multilyzer - Microfluidic Online Measuring System for the Analysis of Environmentally Relevant Substances KW - Absorptionsspektroskopie KW - Ammonium KW - Analysensystem KW - Blutkreislauf KW - Bodenwasser KW - Düngemittel KW - Echtzeitsystem KW - Fluoreszenzspektroskopie KW - Messgerät KW - Messsystem KW - Mikrofluidik KW - Nachhaltigkeit KW - Nitrat KW - Nitrit KW - Online-Messung KW - Programmsteuerung KW - Stickstoff Y1 - 2017 SN - 978-3-8007-4491-6 SP - 382 EP - 385 PB - VDE-Verlag CY - München ER - TY - CHAP A1 - Bieker, Johannes A1 - Roustaie, Farough A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Schlaak, Helmut F. T1 - Innovatives Verfahren zur Herstellung und Integration metallischer Nanokonen für die Feldemission T2 - MikroSystemTechnik Kongress 2017 : MEMS, Mikroelektronik, Systeme 23.-25. Oktober 2017 in München N2 - In den letzten Jahren wurde am Institut für Elektromechanische Konstruktionen die Fabrikation und Integration von metallischen Nanodrähten und Nanokonen mittels Template-basierter Abscheidung erforscht. Diese Variante der in-situ Abscheidung von metallischen Nanostrukturen bietet eine Vielzahl von Anwendungsmöglichkeiten. Im Rahmen dieses Beitrags werden das Herstellungsverfahren zur Herstellung metallischer Nanokonen vorgestellt. Dies beinhaltet sowohl die Templatepräparation mittels asymmetrischen Ätzens als auch die anschließende Integration mittels galvanischer Abscheidung. Eine Anwendung der metallischen Nanokonen stellt die Verwendung als Feldemitter in der Vakuumelektronik dar. Es werden erste Messungen der Langzeitstabilität des Feldemissionsstromes der metallischen Konen präsentiert. N2 - Recently the fabrication and integration of metallic nanowires and nanocones based on ion-track etched templates has been in the focus of research at the Institute for Electromechanical Design at the TU Darmstadt. Using the method for the in-situ deposition various applications are feasible. In this paper we present the fabrication method for in-situ deposition of metallic nanocones, including the preparation of the polymer templates based on asymmetric etching and the process description for integration via electrodeposition. Giving one example for an application, the metallic nanocones can be used as field emitters in vacuum electronics. The field emission properties will be presented briefly. T2 - Innovative fabrication method for in-situ deposition of metallic nanocones for field emission KW - Ätzen KW - Feldemission KW - galvanische Abscheidung KW - Herstellverfahren KW - Langzeitstabilität KW - Nanodraht KW - Nanostruktur KW - Polymer KW - Prozessbeschreibung KW - Vakuum Y1 - 2017 SN - 978-3-8007-4491-6 IS - CD-ROM SP - 797 EP - 800 PB - VDE-Verlag CY - München ER - TY - INPR A1 - Amat, A. A1 - Halimah, M. K. A1 - Ishak, M. A1 - Nazrin, S. N. A1 - Syamimi, Nik Nur A1 - Hasnimulyati, L. T1 - Electronic Polarizability and Optical Basicity of BaO-B2O3-TeO2 Glass System N2 - [(TeO2)0.7(B2O3)0.3]1-x (BaO)x, x = 0.00, 0.05, 0.10, 0.20, 0.25, 0.30 and 0.35 mol fraction glass series were successfully synthesized by conventional melt quenching method. Amorphous phase of all samples was confirmed through X-ray diffraction while optical properties were determined using UV-VIS spectrophotometer. Fourier Transform Infrared (FTIR) analysis showed that the glass structure consisted of TeO3, TeO4, TeO6, BO3 and BO4 structural units. The optical band gap energy, Eopt which was calculated from Tauc’ plots decreased as the amount of BaO increases, whereas, the Urbach energy value increased. The increase in Urbach energy value was attributed to the increase of defects in glass structure. The refractive indices of glass were found to increase along with the increased amount of BaO, due to the high polarization and high density of host material and glass modifier. The molar polarizability, αm, oxide ion polarizability, αo2- and optical basicity, Λ of the glasses are calculated by Lorentz-Lorenz equation. The glasses were found to possess αm values between 8.106 – 8.489 Å3, and αo2- values between 3.303 to 4.772. Meanwhile, optical basicity increases from 0.115 to 0.893.

Y1 - 2021 U6 - https://doi.org/10.21203/rs.3.rs-1093838/v1 ET - Version 1, posted 30 Nov, 2021 ER - TY - CHAP A1 - Rahiman, Mohd Fuad A1 - Berndt, Dominik A1 - Schreiner, Rupert T1 - Micro-wire Pirani with temperature-stabilized Environment T2 - 3. Symposium Elektronik und Systemintegration ESI 2022: 06. April 2022, Hochschule Landshut Y1 - 2022 SN - 978-3-9818439-7-2 SP - 52 EP - 59 ER - TY - GEN A1 - Schreiner, Rupert T1 - Miniaturized sensor and actuator elements based on the heat transport in gases or the ionization of gas particles T2 - 16th International Conference on Optical and Electronic Sensors, COE'2020, 29 March - 2 April 2020, Krakow, Poland (online) Y1 - 2021 ER - TY - CHAP A1 - Kleshch, Victor I. A1 - Serbun, Pavel A1 - Orekhov, Anton A1 - Lützenkirchen-Hecht, Dirk A1 - Obraztsov, Alexander N. A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Lutzenkirchen-Hecht, Dirk T1 - Field emission properties of p-type silicon tips decorated with tungsten nanoparticles T2 - 2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany N2 - An array of conical-shaped p-type silicon tips was fabricated by using reactive ion etching and sharpening oxidation. The apex of each tip was decorated by a tungsten hemispherical nanoparticle. Field emission properties of the tips were measured by a tungsten-needle anode positioned above the tip apex. Tips decorated with tungsten nanoparticles demonstrated a smaller saturation region in current-voltage characteristics compared to the pristine tips. An emission activation process, which consisted in sudden current increase at certain value of applied voltage, was observed for the decorated silicon tips. This behavior was explained by the formation of vertical protrusions extending from the metal particles revealed by scanning electron microscopy after field emission experiments. KW - Current measurement KW - field emission KW - Ions KW - Iron KW - metal nanoparticles KW - nanoparticles KW - p-type silicon KW - Scanning electron microscopy KW - silicon KW - Tungsten Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051580 SP - 138 EP - 139 PB - IEEE ER - TY - CHAP A1 - Knapp, Wolfram A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Lindner, Matthias A1 - Schreiner, Rupert T1 - Investigations of the transition from field electron emission to stable plasma discharge in a micro electron source at vacuum pressure T2 - 2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany N2 - We report on the transition from field electron emission to plasma discharges. During an experiment with a miniaturized field emission electron source a plasma discharge accompanied by a luminous effect was observed. A novel graphical evaluation method was used to interpret and to compare the observed phenomenon. KW - CATHODES KW - Discharges (electric) KW - electron source KW - electron sources KW - Fault location KW - field emission KW - field emission measurement KW - glow discharge KW - Glow discharges KW - micro arc KW - plasma discharge KW - Plasmas KW - Si-tip cathode Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051594 SP - 166 EP - 167 PB - IEEE ER - TY - CHAP A1 - Hiyama, Toru A1 - Sehr, Armin A1 - Yoshida, Takahiro A1 - Hangai, Seiichiro T1 - Text/Language-Independent Unknown Speaker Rejection Method Using LSP Codes T2 - IEEE 9th Global Conference on Consumer Electronics (GCCE 2020): 13-16 Oct. 2020, Kobe, Japan N2 - Scam phone calls pretending relatives have become a major social problem. However, current countermeasure against such scam phone calls stays only enlightenment activities although there is a limited number of technical measures in telephones. In this study, we have proposed a text-independent unknown speaker rejection method which recognizes whether a known speaker or an unknown speaker on receiving a call. In this method, we used a line spectral pair (LSP) spectrogram as the feature and a convolutional neural network (CNN) as the identification engine. From the evaluated results, the proposed method recognized known/unknown speakers with the false acceptance rate (FAR) of 13.1% in Japanese speech and 25.2% in German speech, respectively. Y1 - 2020 U6 - https://doi.org/10.1109/GCCE50665.2020.9291835 ER - TY - JOUR A1 - Walter, Stefanie A1 - Schwanzer, Peter A1 - Hagen, Gunter A1 - Haft, Gerhard A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Moos, Ralf T1 - Modelling the Influence of Different Soot Types on the Radio-Frequency-Based Load Detection of Gasoline Particulate Filters JF - Sensors N2 - Gasoline particulate filters (GPFs) are an appropriate means to meet today's emission standards. As for diesel applications, GPFs can be monitored via differential pressure sensors or using a radio-frequency approach (RF sensor). Due to largely differing soot properties and engine operating modes of gasoline compared to diesel engines (e.g., the possibility of incomplete regenerations), the behavior of both sensor systems must be investigated in detail. For this purpose, extensive measurements on engine test benches are usually required. To simplify the sensor development, a simulation model was developed using COMSOL Multiphysics((R)) that not only allowed for calculating the loading and regeneration process of GPFs under different engine operating conditions but also determined the impact on both sensor systems. To simulate the regeneration behavior of gasoline soot accurately, an oxidation model was developed. To identify the influence of different engine operating points on the sensor behavior, various samples generated at an engine test bench were examined regarding their kinetic parameters using thermogravimetric analysis. Thus, this compared the accuracy of soot mass determination using the RF sensor with the differential pressure method. By simulating a typical driving condition with incomplete regenerations, the effects of the soot kinetics on sensor accuracy was demonstrated exemplarily. Thereby, the RF sensor showed an overall smaller mass determination error, as well as a lower dependence on the soot kinetics. KW - diesel particulate filter (DPF) KW - EMISSIONS KW - finite element method (FEM) KW - FLOW KW - gasoline particulate filter (GPF) KW - PRESSURE-DROP KW - radio frequency (RF) KW - REGENERATION KW - soot mass determination KW - STORAGE Y1 - 2020 U6 - https://doi.org/10.3390/s20092659 VL - 20 IS - 9 SP - 1 EP - 19 PB - MDPI ER - TY - JOUR A1 - Wunderlich, Lukas A1 - Hausler, Peter A1 - Maerkl, Susanne A1 - Bierl, Rudolf A1 - Hirsch, Thomas T1 - Nanoparticle Determination in Water by LED-Excited Surface Plasmon Resonance Imaging JF - Chemosensors N2 - The increasing popularity of nanoparticles in many applications has led to the fact that these persistent materials pollute our environment and threaten our health. An online sensor system for monitoring the presence of nanoparticles in fresh water would be highly desired. We propose a label-free sensor based on SPR imaging. The sensitivity was enhanced by a factor of about 100 by improving the detector by using a high-resolution camera. This revealed that the light source also needed to be improved by using LED excitation instead of a laser light source. As a receptor, different self-assembled monolayers have been screened. It can be seen that the nanoparticle receptor interaction is of a complex nature. The best system when taking sensitivity as well as reversibility into account is given by a dodecanethiol monolayer on the gold sensor surface. Lanthanide-doped nanoparticles, 29 nm in diameter and with a similar refractive index to the most common silica nanoparticles were detected in water down to 1.5 mu g mL(-1). The sensor can be fully regenerated within one hour without the need for any washing buffer. This sensing concept is expected to be easily adapted for the detection of nanoparticles of different size, shape, and composition, and upon miniaturization, suitable for long-term applications to monitor the quality of water. KW - ENGINEERED NANOPARTICLES KW - imaging KW - nanoparticle KW - plasmon resonance KW - REFRACTIVE-INDEX KW - sensor KW - surface Y1 - 2021 U6 - https://doi.org/10.3390/chemosensors9070175 SN - 2227-9040 VL - 9 IS - 7 SP - 1 EP - 9 PB - MDPI ER - TY - JOUR A1 - Schreiner, Rupert A1 - Schweizer, Heinz C. T1 - High-frequency operation of 1.57-μm laterally coupled distributed feedback lasers with self-aligned ohmic contacts and nickel surface gratings JF - IEEE Journal of Selected Topics in Quantum Electronics N2 - Laterally coupled distributed feedback lasers with self-aligned ohmic contacts show the advantage of a considerably simplified fabrication process. These lasers exhibit superior spectral properties with full benefit from the gain coupling mechanism. Side-mode suppression ratios up to 55- and 3-dB bandwidths beyond 15 GHz were obtained for these devices. KW - Distributed feedback devices KW - Optical coupling KW - Laser feedback KW - Ohmic contacts KW - Nickel KW - Surface emitting lasers KW - Gratings KW - Optical device fabrication KW - Mechanical factors KW - Bandwidth Y1 - 2003 U6 - https://doi.org/10.1109/JSTQE.2003.819469 VL - 9 IS - 5 SP - 1179 EP - 1182 PB - IEEE ER - TY - CHAP A1 - Hausler, Peter A1 - Roth, Carina A1 - Vitzthumecker, Thomas A1 - Bierl, Rudolf ED - Ribeiro, Paulo ED - Raposo, Maria T1 - Miniaturized Surface Plasmon Resonance Based Sensor Systems BT - Opportunities and Challenges T2 - Optics, Photonics and Laser Technology 2018 N2 - Surface Plasmon Resonance (SPR) is a well-known and established technology in bioanalysis and pharmaceutical sciences. Due to the expensive instrumentation and the need of trained people, it is mainly limited to applications in laboratories. However, there are some areas like environmental monitoring, chemical processing and civil infrastructure, which urgently need new sensor technologies. SPR has the potential to serve these fields. In order to be qualified for a use in these areas SPR has to overcome some hurdles. The instrumentation has to be robust, small in size and cheap. A device, which fits these needs, will be a micro-opto-electro-mechanical system (MOEMS) with integrated intelligent algorithms. In this book chapter, examples of miniaturized SPR devices are introduced, the limitations which have to be overcome as well as the possibilities for future applications are proposed. Due to the manifold advantages of this technology and the dropping prices for imaging sensors, Surface Plasmon Resonance imaging (SPRi) might become one of the leading technologies for SPR smart sensor systems. Y1 - 2019 SN - 978-3-030-30112-5 U6 - https://doi.org/10.1007/978-3-030-30113-2_8 SP - 169 EP - 195 PB - Springer Nature CY - Cham ER - TY - CHAP A1 - Schwindl, Tobias A1 - Volbert, Klaus A1 - Schwab, Maximilian ED - Benavente-Peces, César ED - Cam-Winget, Nancy ED - Fleury, Eric ED - Ahrens, Andreas T1 - On Update Protocols in Wireless Sensor Networks T2 - Sensor Networks N2 - There has been a lot of research been done in the domain of Wireless Sensor Networks in recent years. Nowadays, Wireless Sensor Networks are in operation in a wide range of different scenarios and applications, like energy management services, heat and water billing as well as smoke detectors. However, research and development will be continued in this domain. During the operation of such a network, software updates need to be done seldom. In contrast to this, software updates need to be done very frequently during development and testing for uploading a new firmware on umpteen nodes. In this paper, we examine such a software update for a particular, but popular and often used sensor network platform. There are already interesting research papers about the process of updating sensor nodes. Our specific focus relies on the technical part of such an update process. We will argue why these already existing update processes do not cover our defiances. The objective of our software update protocol is to enable the developer to update many nodes in a reliable and very fast fashion during the development and testing process. For this reason, energy consumption is considered only marginally. We do not need a multi-hop protocol, due to the fact that all devices are in range, e.g. in a laboratory. In this paper we survey well known update protocols and architectures for software updates in WSN, discuss the solutions and compare them to our approach. As a conclusion of our extensive simulation follows to sum up that the developed protocols do a fast and scalable as well as a reliable update. KW - Low-power devices KW - Software update KW - WSN Y1 - 2019 SN - 978-3-030-30109-5 U6 - https://doi.org/10.1007/978-3-030-30110-1_5 SP - 74 EP - 97 PB - Springer International Publishing CY - Cham ER - TY - JOUR A1 - Dams, Florian A1 - Schreiner, Rupert T1 - Influencing factors on the sensitivity of MEMS-based thermal conductivity vacuum gauges JF - Journal of vacuum science & technology A N2 - The measurement range of thermal conductivity vacuum gauges is mainly influenced by the sensitivity of the sensing element to variations in pressure. An enhanced definition of sensitivity shows its theoretical dependence on the geometric measures of the sensor element at the whole pressure range. This value gives the possibility of direct comparison between different types of sensor structures without the influence of the operating conditions. To study the influencing factors, sensor chips with heated surfaces in the order of some tens of mm 2 were realized by microelectromechanical systems-based fabrication techniques. By a silicon-glass hybrid process two cold planes were formed in a distance of 150 mu m above and below the heated element. The thermal conductance of devices with different geometric measures was determined in constant temperature operating mode by usage of embedded measurement equipment. In this configuration the sensor signals were sensitive to pressure in a region from 10(-5) mbar. The sensitivity was extracted by a fit of the theoretical model to the measurement data and showed the predicted dependencies on the geometric measures. (C) 2014 American Vacuum Society. KW - Pirani Gauge KW - Pressure Sensor Y1 - 2014 U6 - https://doi.org/10.1116/1.4867486 VL - 32 IS - 3 PB - AVS ER - TY - JOUR A1 - Kieninger, Martin A1 - Zech, Nina A1 - Mulzer, Yvonne A1 - Bele, Sylvia A1 - Seemann, Milena A1 - Künzig, Holger A1 - Schneiker, André A1 - Gruber, Michael T1 - Optimierung von Blutgasanalysen auf der Intensivstation. Reduzierung präanalytischer Fehler und Verbesserung der zeitlichen Abläufe JF - Anaesthesist N2 - Kontinuierliche Bemühungen zur Vermeidung präanalytischer Fehler und zur Optimierung der zeitlichen Abläufe bei der Blutgasanalyse (BGA) sind wichtig. In einer prospektiven Beobachtungsstudie wurde untersucht, ob durch Einführung neuer, mit einem Strichcode versehener Probennehmer und von Analysatoren mit automatisierter Verarbeitung der Proben, verglichen mit dem bisherigen Vorgehen, Vorteile resultieren. In einer jeweils 4-wöchigen Testphase wurde für das herkömmliche BGA-System (Kontrollgruppe) und unter Verwendung der neuen, mit einem Strichcode versehenen Probennehmer und automatischer Prozessierung der Blutproben (Testgruppe) die Zeitdauer bis zum Vorliegen der Ergebnisse bei Durchführung einer BGA gemessen. Zudem wurde die Häufigkeit präanalytischer Fehler quantifiziert. Schließlich wurde untersucht, ob eine Liegedauer der Probennehmer von 10 min vor Vermessung der Probe Auswirkungen auf die resultierenden Ergebnisse des Sauerstoff- (pO2) und des Kohlendioxidpartialdrucks (pCO2) hat. In der Kontrollgruppe zeigten sich häufig präanalytische Fehler (Vernachlässigen des Entlüftens der Probennehmer und der Homogenisierung mithilfe des manuellen Schwenkens vor Beginn des Messvorgangs). Bei Analyse von BGA-Proben mit einer zeitlichen Latenz von 10 min nach Abnahme wurden in der Kontrollgruppe signifikant erhöhte pO2-Werte [Mittelwert (MW) 118,4 mmHg bei Messung unmittelbar nach Abnahme, MW 148,6 mmHg bei Messung mit 10-min-Latenz] und signifikant erniedrigte pCO2-Werte (40,5 vs. 38,3 mmHg) gemessen. In der Testgruppe zeigten sich signifikant erhöhte pO2-Werte (115,3 vs. 123,7 mmHg); die pCO2-Werte waren hier unverändert. Ein Zeitgewinn bis zum Vorliegen der Messergebnisse ließ sich in der Testgruppe nicht feststellen. Die Umstellung auf mit einem Strichcode versehene Probennehmer und automatisierte Verarbeitung der Blutproben am Analysator war im klinischen Alltag problemlos möglich. Ein Zeitgewinn bei der BGA resultierte nicht. Allerdings waren Vorteile im Hinblick auf die Reduzierung präanalytischer Fehler erkennbar. Eine verzögerte Analyse von Blutproben kann, abhängig vom Typ des Probennehmers, zu signifikanten und klinisch relevanten Veränderung der Messwerte von pO2 und pCO2 führen. Point of care testing with blood gas analysis (BGA) is an important factor for intensive care medicine. Continuous efforts to optimize workflow, improve safety for the staff and avoid preanalytical mistakes are important and should reflect quality management standards. In a prospective observational study it was investigated whether the implementation of a new system for BGA using labeled syringes and automated processing of the specimens leads to improvements compared to the previously used procedure. In a 4-week test period the time until receiving the final results of the BGA with the standard method used in the clinical routine (control group) was compared to the results in a second 4-week test period using the new labeled syringes and automated processing of the specimens (intervention group). In addition, preanalytical mistakes with both systems were checked during routine daily use. Finally, it was investigated whether a delay of 10 min between taking and analyzing the blood samples alters the results of the BGA. Preanalytical errors were frequently observed in the control group where non-deaerated samples were recorded in 87.3 % but in the intervention group almost all samples (98.9 %) were correctly deaerated. Insufficient homogenization due to omission of manual pivoting was seen in 83.2 % in the control group and in 89.9 % in the intervention group; however, in the intervention group the samples were homogenized automatically during the further analytical process. Although a survey among the staff revealed a high acceptance of the new system and a subjective improvement of workflow, a measurable gain in time after conversion to the new procedure could not be seen. The mean time needed for a complete analysis process until receiving the final results was 244 s in the intervention group and 201 s in the control group. A 10-min delay between taking and analyzing the blood samples led to a significant and clinically relevant elevation of the values for partial pressure of oxygen (pO(2)) in both groups compared to the results when analyzing the samples immediately (118.4 vs. 148.6 mmHg in the control group and 115.3 vs. 123.7 mmHg in the intervention group). When using standard syringes the partial pressure of carbon dioxide (pCO(2)) was significantly lower (40.5 vs. 38.3 mmHg) whereas no alterations were seen when using the labeled syringes. The implementation of a new BGA system with labeled syringes and automated processing of the specimens was possible without any difficulties under daily clinical routine conditions in this 10-bed intensive care unit (ICU). A gain of time could not be measured but a reduction in preanalytical errors using the labeled syringes with automated processing was found. Delayed analysis of blood samples can lead to significant changes in pO(2) and pCO(2) depending on the type of syringe used. KW - Acid base balance KW - Beobachtungsstudie KW - Intensive care medicine KW - Intensivmedizin KW - Observational study KW - Point of care systems KW - „Point-of-care“-Systeme KW - Qualitätsmanagement KW - Quality management KW - Säure-Basen-Haushalt KW - WHOLE-BLOOD Y1 - 2015 U6 - https://doi.org/10.1007/s00101-015-0024-8 VL - 64 IS - 5 SP - 365 EP - 372 PB - Springer Nature ER - TY - JOUR A1 - Sindersberger, Dirk A1 - Diermeier, Andreas A1 - Prem, Nina A1 - Monkman, Gareth J. T1 - Printing of hybrid magneto active polymers with 6 degrees of freedom JF - Materials today communications N2 - 3D printing techniques offer a versatile method for the fabrication and structuring of magnetoactive polymer (MAP) components and devices for research prototype development. MAP materials enjoy an advantage in that the particulate content may be manipulated by external magnetic fields during the forming and curing processes. Controlled particle diffusion within the polymer matrix, by means of external fields applied during the printing process, influences a further three spatial dimensions. This permits control of the spatial particle concentration and makes free displacement of particle accumulations possible during the crosslinking phase. Particles which are susceptible to electric or magnetic fields can thereby be shifted into regions previously free of particles. The additional 3 graded dispersion axes effectively results in what can be described as 6 degrees of freedom (6DOF) printing. Electrically conductive polymers combined with non-conductive areas, provide an additional benefit for the production of complex hybrid structures. This may be augmented by the combination of magnetically active thermoplastics as inelastic structural components together with mechanically deformable elastomers. The combination of all fabrication methods in one hybrid printing process makes the production of complex sensor and actuator systems in one manufacturing sequence possible. This far exceeds the capabilities of conventional casting and machining operations and opens new possibilities for the fabrication of soft material elements. KW - 3D printing KW - Conductive polymer KW - Hybrid KW - Magnetoactive KW - Polymer Y1 - 2018 U6 - https://doi.org/10.1016/j.mtcomm.2018.02.032 VL - 15 IS - June SP - 269 EP - 274 PB - Elsevier ER -