TY - JOUR A1 - Mauerer, Wolfgang A1 - Rexhepaj, Tanja A1 - Monkman, Gareth J. A1 - Sindersberger, Dirk A1 - Diermeier, Andreas A1 - Neidhart, Thomas A1 - Wolfrum, Dominik A1 - Sterner, Michael A1 - Heberl, Michael A1 - Nusko, Robert A1 - Maier, Georg A1 - Nagl, Klaus A1 - Reuter, Monika A1 - Hofrichter, Andreas A1 - Lex, Thomas A1 - Lesch, Florian A1 - Kieninger, Bärbel A1 - Szalo, Alexander Eduard A1 - Zehner, Alexander A1 - Palm, Christoph A1 - Joblin, Mitchell A1 - Apel, Sven A1 - Ramsauer, Ralf A1 - Lohmann, Daniel A1 - Westner, Markus A1 - Strasser, Artur A1 - Munndi, Maximilian A1 - Ebner, Lena A1 - Elsner, Michael A1 - Weiß, Nils A1 - Segerer, Matthias A1 - Hackenberg, Rudolf A1 - Steger, Sebastian A1 - Schmailzl, Anton A1 - Dostalek, Michael A1 - Armbruster, Dominik A1 - Koch, Fabian A1 - Hierl, Stefan A1 - Thumann, Philipp A1 - Swidergal, Krzysztof A1 - Wagner, Marcus A1 - Briem, Ulrich A1 - Diermeier, Andreas A1 - Spreitzer, Stefan A1 - Beiderbeck, Sabrina A1 - Hook, Christian A1 - Zobel, Martin A1 - Weber, Tim A1 - Groß, Simon A1 - Penzkofer, Rainer A1 - Dendorfer, Sebastian A1 - Schillitz, Ingo A1 - Bauer, Thomas A1 - Rudolph, Clarissa A1 - Schmidt, Katja A1 - Liebetruth, Thomas A1 - Hamer, Markus A1 - Haug, Sonja A1 - Vernim, Matthias A1 - Weber, Karsten A1 - Saßmannshausen, Sean Patrick A1 - Books, Sebastian A1 - Neuleitner, Nikolaus A1 - Rechenauer, Christian A1 - Steffens, Oliver A1 - Kusterle, Wolfgang A1 - Gömmel, Roland A1 - Wellnitz, Felix A1 - Stierstorfer, Johannes A1 - Stadler, Dominik A1 - Hofmann, Matthias J. A1 - Motschmann, Hubert A1 - Shamonin (Chamonine), Mikhail A1 - Bleicher, Veronika A1 - Fischer, Sebastian A1 - Hackenberg, Rudolf A1 - Horn, Anton A1 - Kawasch, Raphael A1 - Petzenhauser, Michael A1 - Probst, Tobias A1 - Udalzow, Anton A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian ED - Baier, Wolfgang T1 - Forschungsbericht 2016 T3 - Forschungsberichte der OTH Regensburg - 2016 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-13840 CY - Regensburg ER - TY - GEN A1 - Sindersberger, Dirk A1 - Diermeier, Andreas A1 - Monkman, Gareth J. T1 - Investigation of the electrical properties of magneto-active polymers - Poster T2 - DFG-Tagung, Benedikbeuern, September 2016 Y1 - 2016 ER - TY - JOUR A1 - Diermeier, Andreas A1 - Sindersberger, Dirk A1 - Krenkel, Lars A1 - Rosell, X. C. A1 - Monkman, Gareth J. T1 - Controllable Magnetoactive Polymer Conduit JF - The Open Mechanical Engineering Journal N2 - Objective: Magneto-active Polymers (MAP) are smart materials whose mechanical characteristics, such as elastic and shear moduli, may be controllable by means of an externally applied magnetic field. Methods: Various additives may be used to influence the characteristics of the polymer matrix whilst a suspension of soft and/or hard magnetic particles determine the magnetic properties of the composite. Both pre-cure and post-cure magnetization is possible. Results: A range of control strategies have been investigated for evaluation of the system using fluids of differing kinematic viscosity. Conclusion: Depending on the degree of magnetic field homogeneity, magneto-deformation and magnetostriction contribute to MAP actuation. This paper presents a novel application in the form of a peristaltic MAP tube system, applicable to flow control and pumping of hemorheological fluids in blood circulatory systems for biomedical research purposes. Y1 - 2018 UR - https://www.benthamopen.com/ABSTRACT/TOMEJ-12-192 N1 - Corresponding authro: Gareth J. Monkman VL - 12 IS - 1 SP - 192 EP - 200 PB - Bentham ER - TY - CHAP A1 - Diermeier, Andreas A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. T1 - Magneto-Active Polymer Actuator T2 - Actuator 16 : 15th International Conference on New Actuators & 9th International Exhibition on Smart Actuators and Drive Systems : conference proceedings N2 - Magneto-active Polymers (MAP) are closely related to magneto-rheological fluids in that they contain magnetic micro-particles. However, instead of being freely suspended in a carrier fluid they are physically bound within a highly elastic polymer-matrix. The application of an external magnetic field allows changes in the mechanical properties, such as elastic and shear moduli, of the composite material to be achieved. The colossal magneto-rheological effect has been shown to demonstrate changes in Young's modulus by over 1E6 %. Current research concentrates on controllable compliance and the resulting shape memory properties of MAP. This paper deals with recent advancements in this respect, including tubular magneto-active devices with potential applications in medical and other technology. KW - Formgedächtniseffekt KW - Kompositwerkstoff KW - Konzentrat KW - magnetisches Feld KW - magnetorheologische Flüssigkeit KW - Polymer KW - Schermodul Y1 - 2016 SN - 978-3-933339-26-3 SP - 286 EP - 289 PB - WFB CY - Bremen ER - TY - JOUR A1 - Monkman, Gareth J. A1 - Sindersberger, Dirk A1 - Diermeier, Andreas A1 - Prem, Nina T1 - The magnetoactive electret JF - smart materials and structures N2 - A magnet which adheres to every surface, not only those of ferromagnetic materials, has hitherto been the domain of science fiction. Now for the first time such a novel device exists. The fusion of a permanently magnetized magnetoactive polymer containing hard magnetic particles and an electret enhanced with ferroelectric particles has resulted in the development of a new smart device-the magnetoactive electret. Magnetoactive electrets can be made to exhibit the usual magnetic properties of permanent magnetism together with the electrostatic properties of electrets. This results in simultaneous magnetoadhesion and electroadhesion forces from the same elastomeric element. The biasing field, needed to avoid discontinuities concerned with transition through the zero point in operating curves, is normally provided by means of either a magnetic or an electric field. This novel technology provides both bias options in a single device. KW - 6D printing KW - electret KW - electroadhesion KW - FLUIDS KW - MAGNETIC-FIELD KW - magnetoactive electret KW - magnetoactive polymer KW - magnetoadhesion KW - Magnetorheological elastomers KW - RHEOLOGY Y1 - 2017 U6 - https://doi.org/10.1088/1361-665X/aa738f VL - 26 IS - 7 PB - IOP Publishing ER - TY - JOUR A1 - Monkman, Gareth J. A1 - Sindersberger, Dirk A1 - Prem, Nina A1 - Diermeier, Andreas A1 - Szecsey, Tamara T1 - Dielectric behaviour of magnetic hybrid materials JF - Physical Sciences Reviews N2 - The objectives of this work include the analysis of electrical and magnetic properties of magneto-elastic hybrid materials with the intention of developing new techniques for sensor and actuator applications. This includes the investigation of dielectric properties at both low and high frequencies. The behaviour of capacitors whose dielectrics comprise magnetic hybrid materials is well known. Such interfacial magnetocapacitance can be varied according to magnetic content, magnetic flux density and the relative permittivity of the polymer matrix together with other dielectric content. The basic function of trapping electrical charges in polymers (electrets) is also established technology. However, the combination of magnetoactive polymers and electrets has led to the first electromagnetic device capable of adhering to almost any material, whether magnetically susceptible or not. During the course of this research, in addition to dielectrics, electrically conductive polymers based on (PDMS) matrices were developed in order to vary the electrical properties of the material in a targeted manner. In order to ensure repeatable results, this demanded new fabrication techniques hitherto unavailable. The 3D printing of silicones is far from being a mature technology and much pioneering work was necessary before extending the usual 3 d.o.f. to include orientation about and diffusion of particles in these three axes, thus leading to the concept of 6D printing. In 6D printing, the application of a magnetic field can be used during the curing process to control the particulate distribution and thus the spatial filler particle density as desired. Most of the devices (sensors and actuators) produced by such methods contain levels of carbonyl iron powder (CIP) embedded magnetic filler of up to 70 wt%. Contrary to this, a hitherto neglected research area, namely magnetoactive polymers (MAPs) having significantly lower magnetic particle concentrations (1 to 3 wt% CIP) were also investigated. With filler concentrations lower than 3 wt%, structures are formed which are completely absent at higher filler levels. CIP concentrations in the range of 1wt% demonstrate the formation of toroidal structures. Further development of coherent rings with a compact order results as filler concentrations increase towards 2 wt%. Above 3 wt% the structure eventually disintegrates to the usual random order found in traditional MAP with higher CIP content. Structured samples containing 1%–3 wt% CIP were investigated with the aid of X-ray tomography where solitary ring structures can be observed and eventually the formation of capillary doubles. Over wavelengths ranging from 1 to 25 µm, spectroscopic analysis of thin film MAP samples containing 2 wt% CIP revealed measurable magnetic-field-dependent changes in IR absorption at a wavenumber 2350 (λ = 4.255 µm). This was found to be due to the diamagnetic susceptibility of atmospheric carbon dioxide (CO2). Consequently, the first potential application for sparse matrix MAPs was found. KW - cappillary doublet KW - diamagnetic KW - elastomer dielectric KW - FTIR KW - interfacial magnetocapacitance KW - magnetoactive polymer KW - PDMS KW - toroid Y1 - 2021 U6 - https://doi.org/10.1515/psr-2019-0121 N1 - Corresponding author: Gareth J. Monkman VL - 7 IS - 10 SP - 1169 EP - 1185 PB - de Gruyter 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 - 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 - TY - JOUR A1 - Zimmermann, Klaus A1 - Böhm, Valter A1 - Becker T.I., A1 - Chavez Vega, Jhohan Harvey A1 - Kaufhold, Tobias A1 - Monkman, Gareth J. A1 - Sindersberger, Dirk A1 - Diermeier, Andreas A1 - Prem, Nina T1 - Mechanical Characterization of the Field-Dependent Properties of Magnetoactive Polymers and Integrated Electrets for their Application in Soft Robotics JF - International Scientific Journal "Problems of Mechanics" Y1 - 2017 SN - 1512-0740 VL - 69 IS - 4 ER -