TY - CHAP A1 - Khaled, W. A1 - Reichling, S. A1 - Bruhns, Otto T. A1 - Monkman, Gareth J. A1 - Egersdörfer, Stefan A1 - Baumann, Michael A1 - Böse, Holger A1 - Klein, Dagmar A1 - Freimuth, Herbert A1 - Tunayar, A. A1 - Lorenz, A. A1 - Pessavento, A. A1 - Ermert, Helmut T1 - Palpation imaging using a haptic system for virtual reality applications in medicine T2 - Perspective in image-guided surgery : proceedings of the Scientific Workshop on Medical Robotics, Navigation, and Visualization : RheinAhrCampus Remagen, Germany, 11-12 March Y1 - 2004 SP - 407 EP - 414 PB - World Scientific Publ. CY - Singapore ER - TY - CHAP A1 - Khaled, W. A1 - Reichling, S. A1 - Bruhns, Otto T. A1 - Monkman, Gareth J. A1 - Egersdörfer, Stefan A1 - Baumann, Michael A1 - Böse, Holger A1 - Klein, Dagmar A1 - Freimuth, Herbert A1 - Tunayar, A. A1 - Lorenz, A. A1 - Pessavento, A. A1 - Ermert, Helmut T1 - Palpation Imaging using a Haptic System for Virtual Reality Applications in Medicine T2 - Proceedings of the 12th Annual Medicine Meets Virtual Reality Conference: - Building a Better You: The Next Tools for Medical Education, Diagnosis, and Care. - Medicine Meets Virtual Reality (MMVR) - Newport Beach (California, USA). 2004 Y1 - 2004 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 - Freimuth, Herbert A1 - Tunayar, A. A1 - Ermert, Helmut T1 - A New Haptic Sensor Actuator System for Virtual Reality Applications in Medicine T2 - Medical Image Computing and Computer-Assisted Intervention - MICCAI 2003: 6th International Conference, Montréal, Canada, November 15-18, 2003, Proceedings Y1 - 2003 SN - 978-3540204626 SP - 132 EP - 140 PB - Springer ER - TY - JOUR 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 system for virtual reality applications based on ultrasound elastography and electrorheological fluids JF - Acoustical Imaging Y1 - 2004 U6 - https://doi.org/10.1007/978-1-4020-2402-3_85 IS - 27 SP - 667 EP - 675 PB - Kluver Academic CY - Dordrecht & New York ER - TY - CHAP A1 - Khaled, W. A1 - Reichling, S. A1 - Bruhns, Otto T. A1 - Ermert, Helmut A1 - Monkman, Gareth J. A1 - Egersdörfer, Stefan A1 - Baumann, Michael A1 - Böse, Holger A1 - Freimuth, Herbert A1 - Tunayar, A. T1 - Palpation imaging using a haptic sensor actuator system for medical applications T2 - Actuator 2004 : 9th International Conference on New Actuators & 3rd International Exhibition on Smart Actuators and Drive Systems, 14-16 June 2004, Bremen, Germany Y1 - 2004 SP - 379 EP - 382 PB - HVG Hanseatische Veranstaltungs-GmbH CY - Bremen 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 - Heckner, T. A1 - Kessler, C. A1 - Egersdörfer, Stefan A1 - Monkman, Gareth J. T1 - Computer based platform for tactile actuator analysis T2 - Actuator 2006 : 10th International Conference on New Actuators and 4th International Exhibition on Smart Actuators and Drive Systems, Bremen, Germany, 14 - 16 June 2006 Y1 - 2006 PB - HVG Hanseatische Veranst.-GmbH 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 - GEN A1 - Monkman, Gareth J. A1 - Sindersberger, Dirk T1 - Investigation of the electrical properties of magneto-active polymers T2 - DFG-Tagung, Benedikbeuern, September 2015 Y1 - 2015 ER - TY - CHAP A1 - Niklas, Andreas A1 - Hiller, Karl-Anton A1 - Jäger, Andreas A1 - Brandt, M. A1 - Putzger, Jürgen A1 - Ermer, C. A1 - Schulz, Irene A1 - Monkman, Gareth J. A1 - Giglberger, Stephan A1 - Hirmer, Marion A1 - Danilov, Sergey N. A1 - Ganichev, Sergey D. A1 - Schmalz, Gottfried ED - Arenholt-Bindslev, Dorthe ED - Schmalz, Gottfried T1 - In vitro optical detection of simulated blood pulse in a human tooth pulp model T2 - Biocompatibility of Dental Materials Y1 - 2013 PB - Springer CY - Berlin ; Heidelberg ER - TY - JOUR A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Striegl, Birgit A1 - Böhm, Valter A1 - Monkman, Gareth J. T1 - Shape memory effects using magnetoactive Boron-organo-silicon oxide polymers JF - Macromolecular Chemistry and Physics N2 - Thermomechanical shape memory materials have certain disadvantages when it comes to 3D volumetric reproduction intended for rapid prototyping or robotic prehension. The need to constantly supply energy to counteract elastic retraction forces in order to maintain the required geometry, together with the inability to achieve conformal stability at elevated temperatures, limits the application of thermal shape memory polymers. Form removal also presents problems as most viscoelastic materials do not ensure demolding stability. This work demonstrates how magnetoactive boron−organo−silicon oxide polymers under the influence of an applied magnetic field can be used to achieve energy free sustainable volumetric shape memory effects over extended periods. The rheopectic properties of boron−organo−silicon oxide materials sustain form removal without mold distortion. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-23205 N1 - Corresponding Author: Gareth J. Monkman VL - 221 IS - 15 SP - 1 EP - 8 PB - Wiley ER - TY - JOUR A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Börner, Juliane A1 - Hörner, Eva A1 - Bentz, Alexander A1 - Salgado, Josefina A1 - Han, Hong A1 - Böse, Holger A1 - Probst, Jörn A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Schlunck, Günther T1 - Ultra-Soft PDMS-Based Magnetoactive Elastomers as Dynamic Cell Culture Substrata JF - PLoS ONE N2 - Mechanical cues such as extracellular matrix stiffness and movement have a major impact on cell differentiation and function. To replicate these biological features in vitro, soft substrata with tunable elasticity and the possibility for controlled surface translocation are desirable. Here we report on the use of ultra-soft (Young’s modulus <100 kPa) PDMS-based magnetoactive elastomers (MAE) as suitable cell culture substrata. Soft non-viscous PDMS (<18 kPa) is produced using a modified extended crosslinker. MAEs are generated by embedding magnetic microparticles into a soft PDMS matrix. Both substrata yield an elasticity-dependent (14 vs. 100 kPa) modulation of α-smooth muscle actin expression in primary human fibroblasts. To allow for static or dynamic control of MAE material properties, we devise low magnetic field (≈40 mT) stimulation systems compatible with cell-culture environments. Magnetic field-instigated stiffening (14 to 200 kPa) of soft MAE enhances the spreading of primary human fibroblasts and decreases PAX-7 transcription in human mesenchymal stem cells. Pulsatile MAE movements are generated using oscillating magnetic fields and are well tolerated by adherent human fibroblasts. This MAE system provides spatial and temporal control of substratum material characteristics and permits novel designs when used as dynamic cell culture substrata or cell culture-coated actuator in tissue engineering applications or biomedical devices. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0076196 VL - 8 IS - 10 PB - PLOS ER - TY - JOUR A1 - Forster, Eva A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Böse, Holger A1 - Schlunck, Günther A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail T1 - Patterning of ultrasoft, agglutinative magnetorheological elastomers JF - Journal of applied polymer science N2 - A low-cost wax-cast molding technique for structuring ultrasoft (Young’s modulus ≤ 40 kPa), agglutinative magnetorheological elastomer (MRE) material is presented. MRE structures ranging from a few millimeters down to the micrometer range with highly reproducible results are possible. Semitransparent MREs are also fabricated and their surfaces modified accordingly. This method opens new possibilities for MREs in biomedical engineering and microfluidic applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 Y1 - 2013 U6 - https://doi.org/10.1002/app.38500 VL - 128 IS - 4 SP - 2508 EP - 2515 PB - Wiley CY - New York, NY 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 - JOUR A1 - Loo, Xuyan A1 - Nagaraju, Bhavana A1 - Pathivada, Sai A1 - Bartsch, Alexander A1 - Schratzenstaller, Thomas A1 - Sattler, Robert A1 - Monkman, Gareth J. T1 - Electrical properties of bisphenol-A-free magnetoactive borosilicate polymers JF - AIP Advances N2 - The recent REACH regulations require the elimination of bisphenol-A and titanium dioxide from commercially available boron-based polymers. This has led to changes in some of the mechanical characteristics, which strongly influence the properties of magnetoactive borosilicate polymers. This work delivers results on the electrical properties and discusses some implications for future research using bisphenol-A and titanium-dioxide-free substitutes. KW - Electrical components KW - Electrical properties and parameters KW - Dielectric properties KW - Electrical resistivity KW - Magnetic materials KW - Viscoelasticity KW - Polymers KW - Non Newtonian fluids KW - Magnetic fluids Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-72936 SN - 2158-3226 N1 - Corresponding author der OTH Regensburg: Gareth J. Monkman VL - 14 IS - 5 PB - AIP Publishing ER - TY - JOUR A1 - Klein, Dagmar A1 - Freimuth, Herbert A1 - Monkman, Gareth J. A1 - Egersdörfer, Stefan A1 - Meier, Alexander A1 - Böse, Holger A1 - Baumann, Michael A1 - Ermert, Helmut A1 - Bruhns, Otto T. T1 - Electrorheological Tactile Elements JF - Mechatronics N2 - The use of ultrasound systems for medical examination and diagnosis is nothing new. The extension of ultrasound techniques for real time elastographic analysis purposes represents a more recent development. Nevertheless, as they stand all such techniques rely on the interpretation of two-dimensional visual data displayed on a video screen. In reality however, a medical doctor will make as much use of exploratory touch as he or she does vision, making the simultaneous portrayal of both video and tactile information most desirable [Böse H, Monkman GJ, Freimuth H, Ermert H. Haptisches Sensor-Aktor-System uaf der grundlage der Echtzeitelastographie sowie von elktro- und magnetorheologischen Materialien “HASASEM” [3]. BMBF Antrag 01 IR A14D, Oktober 2000]. This paper discusses the preliminary tests and basic design parameters for single tactels using electrorheological fluids. The final aim is to produce a prototype three-dimensional tactile display comprising electrically switchable micro-machined cells whose mechanical moduli are governed by phase changes experienced by electrorheological fluids. This will be integrated with the latest elastographic ultrasonic sensor systems in order to present the human fingers with controllable surfaces capable of emulating biological tissue, muscle and bone. Y1 - 2005 U6 - https://doi.org/10.1016/j.mechatronics.2004.05.007 VL - 15 IS - 7 SP - 883 EP - 897 PB - Pergamon CY - Oxford ER - TY - JOUR A1 - Klein, Dagmar A1 - Rensink, D. A1 - Freimuth, Herbert A1 - Monkman, Gareth J. A1 - Egersdörfer, Stefan A1 - Böse, Holger A1 - Baumann, Michael T1 - Modelling the Response of a Tactile Array using an Electrorheological Fluids JF - Journal of Physics D: Applied Physics N2 - This paper reports the first step in the development of a tactile array suitable for the presentation of haptic information in virtual reality. The system is based on the electric field dependence of the viscosity of electrorheological fluids. The simulation, as well as the experimental realization of single tactels is described. The mathematical approach is based on the Eckart model (Eckart W 2000 Continuum Mech. Thermodyn. 12 341–62) and its validity is demonstrated by comparing the resulting yield stress with the experimental results from Wunderlich (2000 Dissertation Universität Erlangen-Nürnberg). Two different tactel designs are realized and the experimental results are compared with numerical simulation. The design of modification B is shown to be applicable for the realization of an actuator array with high spatial resolution. Y1 - 2004 U6 - https://doi.org/10.1088/0022-3727/37/5/023 SN - 1361-6463 SN - 0022-3727 VL - 37 IS - 5 SP - 794 EP - 803 PB - IOP Publ. CY - Bristol 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 - Boody, F. P. T1 - Ein Vergleich verschiedene Master-Programme JF - Die Neue Hochschule Y1 - 2003 IS - 1 SP - 12 EP - 13 PB - DUZ Verlags- und Medienhaus GmbH CY - Berlin ER - TY - JOUR A1 - Dillinger, Andrea Elisabeth A1 - Mayer, Matthias A1 - Schneider, Magdalena A1 - Weber, Gregor R. A1 - Goeppner, Corinna A1 - Tamm, Ernst R. A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Fuchshofer, Rudolf T1 - Reactive changes in optic nerve astrocytes are mediated by CTGF, TGF beta 2 and increasing substratum stiffness JF - Investigative ophthalmology & visual science N2 - Purpose: Patients with primary open-angle glaucoma (POAG) show a stiffer peripapillary sclera, reactive astrocytes and a remodeled lamina cribrosa (LC). The changes are thought to be mediated by TGFβ2 and its downstream mediator CTGF. Recently we developed a murine glaucoma model by overexpressing CTGF in the anterior eye (βb1CTGF). In this study we investigated the glial lamina region of βb1CTGF mice, and the changes of astrocytes in response to CTGF and TGFβ2 as well as increasing substratum stiffness. Methods: Tangential sections of the glial LC of 2-month-old βb1CTGF mice and their wild-type littermates (WT) were stained with phalloidin and antibodies against GFAP, CTGF and fibronectin (FN). Murine optic nerve (ON) astrocytes from CD1 mice were isolated, cultured and characterized by GFAP staining. The astrocytes were treated with TGFβ2 (1ng/ml) and CTGF (50ng/ml and 100ng/ml). In addition, the cells were seeded on PDMS substrata with different stiffness (10, 30 and 60 kPa). Treated cells were analyzed by Western blotting, real-time RT-PCR and immunohistochemistry. Wound healing assays were performed to analyze migration rate following growth factor treatment. Results: βb1CTGF mice showed a massive increase in CTGF and GFAP in the glial LC when compared with WT mice. Moreover, an increase in FN staining and phalloidin-labeled actin was observed in the peripapillary sclera. Murine ON astrocytes reacted on increased substrate stiffness by increasing the synthesis of GFAP, vimentin and CTGF. Treatment of the cells with TGFβ2 and CTGF led to an enhanced migration rate. In addition, treatment resulted in an increased expression and synthesis of ECM proteins, including FN, tropoelastin, collagen type I and III. The in vitro findings correlated with those seen in the glaucoma mouse model. Conclusions: We conclude that changes in the ECM of LC and peripapillary sclera alter their biomechanical properties and thereby induce reactive changes in resident astrocytes. The reactive changes induced by higher stiffness of their surrounding ECM give rise to a self-amplifying process that includes increased TGFβ2/CTGF signaling and leads to synthesis of ECM and cytoskeletal proteins, a process that in turn augments the stiffness at the optic nerve head (ONH). Such a scenario may finally result in a vicious circle as the causative mechanism for ONH deformation in POAG. Y1 - 2015 VL - 56 IS - 7 PB - ASSOC RESEARCH VISION OPHTHALMOLOGY INC ER - TY - JOUR A1 - Sorokin, Vladislav V. A1 - Stepanov, Gennady V. A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Khokhlov, Alexei R. A1 - Kramarenko, Elena Yu T1 - Hysteresis of the viscoelastic properties and the normal force in magnetically and mechanically soft magnetoactive elastomers: Effects of filler composition, strain amplitude and magnetic field JF - Polymer N2 - Hysteresis in dynamic modulus, loss factor and normal forces of magnetoactive elastomers (MAEs) comprising various proportions of small (3-5 mu m) and large (50-60 mu m) ferromagnetic particles are experimentally studied using dynamic torsion performed at a fixed oscillation frequency in varying DC magnetic fields. It is shown that hysteresis is a characteristic feature of MAEs observed both under increasing/decreasing magnetic field strength and increasing/decreasing strain amplitude. This hysteresis is attributed to the specific rearrangement of the magnetic filler network under simultaneously applied magnetic field and shear deformation. Rheological properties of the magnetic filler network formed in the magnetic field and, therefore, the rheological properties of MAEs depend strongly on the filler composition and the magnetic field magnitude. Larger magnetic particles and higher magnetic fields provide stronger magnetic networks. Both factors result in the extension of the linear viscoelastic regime to larger strain amplitudes and lead to higher values of shear storage and loss moduli. It is found that the hysteresis width maximises at an intermediate magnetic field where it is attributed to the balance between elastic and magnetic particle interactions. This is apparently where the most significant restructuring of the magnetic network occurs. The hysteresis width decreases with increasing fraction of large particles in the magnetic filler. The loss factor grows significantly when the magnetic network is physically broken by large strains gamma > 1%. A huge (more than one order of magnitude) increase of normal force at maximum magnetic field strengths is observed. It is predicted that any physical quantity depending on the internal structuring of the magnetic filler should demonstrate hysteresis either with a changing magnetic field and constant deformation amplitude or under variable deformation in a constant magnetic field. (C) 2015 Elsevier Ltd. All rights reserved. KW - BEHAVIOR KW - COMPRESSION KW - Dynamic modulus KW - GELS KW - hysteresis KW - Magnetorheological elastomers KW - magnetostriction KW - MODULUS KW - PARTICLES KW - POLYMER COMPOSITES KW - shear Y1 - 2015 U6 - https://doi.org/10.1016/j.polymer.2015.08.040 VL - 76 SP - 191 EP - 202 PB - Elsevier ER -