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 - JOUR A1 - Romano, Marco A1 - Micklitz, Matthias A1 - Olbrich, Florian A1 - Bierl, Rudolf A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Experimental investigation of damping properties of unidirectionally and fabric reinforced plastics by the free decay method JF - Journal of Achievements in Materials and Manufacturing Engineering N2 - Purpose: of this paper is experimental investigation of damping properties of unidirectionally and fabric reinforced plastics by the free decay method. Design/methodology/approach: For the evaluation of the presumed effect experimental structural dynamic investigations comparing unidirectionally and fabric reinforced plastics are carried out. In detail the free decay behaviour of flat beamlike specimens under fixed-free boundary conditions and relatively constant and reproducible displacement excitation is investigated. Findings: The vibrating structure has been measured by a laser scanning vibrometer PSV 400 from POLYTEC. In both cases evaluation of the results yields enhanced damping properties of the specimens with fabric reinforcement compared to the unidirectionally reinforced specimens. The results justify the presumed acting of a mesomechanic kinematic. Research limitations/implications: The results show that in either case the material damping in terms of the logarithmic decrement of the fabric reinforced material is higher than the material damping in of the unidirectionally reinforced material. Additionally, when the fabric reinforced specimens are addressed, in each case the plain weave reinforced specimens exhibited higher values of the material damping as the twill weave 2/2 reinforced ones. Originality/value: Ondulations in fabrics as a textile semi-finished product are caused by the alternating crossing of warp and fill yarns. In the mesoscopic scale the acting of a mesomechanic kinematic is presumed to enhance the damping properties under cyclic elastic deformation. For the evaluation of the presumed effect experimental structural dynamic investigations comparing unidirectionally and fabric reinforced plastics are carried out. KW - structural vibration KW - damping KW - fibre reinforced plastics KW - mesomechanic scale KW - fabric reinforced layer Y1 - 2014 VL - 63 IS - 2 SP - 65 EP - 80 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 - Hofmann, Matthias A1 - Bierl, Rudolf A1 - Rück, Thomas T1 - Implementation of a dual-phase lock-in amplifier on a TMS320C5515 digital signal processor T2 - Proceedings of the 5th European DSP Education and Research Conference (EDERC), 13-14 Sept. 2012, Amsterdam N2 - A digital dual-phase lock-in amplifier that is capable to run on a low-cost, low-power platform comprising a 16-bit fixed-point digital signal processor was developed. This is achieved by a set of optimised digital filters including an exponential averager to adjust the time constant of the overall filter. The reference frequency is generated using a direct digital synthesis source utilising angle decomposition with a resolution of 1 Hz. The digital lock-in algorithm is described and the performance of the algorithm is analysed. The experimental results show that the developed lock-in amplifier achieves similar performance to a commercially available lock-in amplifier. Y1 - 2012 U6 - https://doi.org/10.1109/EDERC.2012.6532217 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 - 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 - 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 - INPR A1 - Rück, Thomas A1 - Müller, Max A1 - Jobst, Simon A1 - Weigl, Stefan A1 - Pangerl, Jonas A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - Digital Twin of a Photoacoustic Trace Gas Sensor for Monitoring Methane in Complex Gas Compositions N2 - The digitalization of industrial processes requires smart sensor systems. Photoacoustic spectroscopy is well suited for this purpose as it allows for small-sized and low-cost trace gas analysis. However, the method is susceptible to changes in measurement conditions and standard calibration routines often fail to correct for all changes. We therefore created a Digital Twin (DT) of a photoacoustic trace gas sensor for methane and evaluated it regarding variations in gas composition (CH4, N2, O2, CO2, H2O), temperature and pressure. With a mean absolute percentage error of 0.8 % the accuracy of the sensor after DT compensation significantly exceeds the 24 % achieved based on standard calibration in nitrogen. For the first time, we can fully analytically compute the photoacoustic signal under moderate ambient conditions with an error in the ppbV range by taking a holistic approach. Assuming knowledge of the underlying energy transfer processes, the model of this Digital Twin can be adapted to any microphone based photoacoustic sensor for monitoring any analyte species. Y1 - 2022 U6 - https://doi.org/10.2139/ssrn.4215170 PB - Elsevier / SSRN ER - TY - CHAP A1 - Müller, Max A1 - Rück, Thomas A1 - Jobst, Simon A1 - Pangerl, Jonas A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - Creating a Digital Twin of a Photoacoustic Gas Sensor for Methane Detection in Complex Gas Matrices T2 - Proceedings Optical Sensors and Sensing Congress 2022 (AIS, LACSEA, Sensors, ES): 11–15 July 2022, Vancouver, British Columbia, Canada N2 - We present the calculation results from a digital twin (DT) of our photoacoustic (PA) sensor for methane detection, regarding gas composition, temperature and pressure variations. Y1 - 2022 SN - 978-1-957171-10-4 U6 - https://doi.org/10.1364/LACSEA.2022.LW4D.2 PB - Optica Publishing Group ER -