TY - CHAP A1 - Böhm, Valter A1 - Schorr, Philipp A1 - Schale, Florian A1 - Kaufhold, Tobias A1 - Zentner, Lena A1 - Zimmermann, Klaus T1 - Worm-Like Mobile Robot Based on a Tensegrity Structure T2 - 2021 IEEE 4th International Conference on Soft Robotics (RoboSoft): 2.04.2021 - 16.04.2021, New Haven, CT, USA N2 - This work presents a novel concept to develop mobile robots enabling crawling locomotion in tubular environment. Chain-like systems are designed by serial cascading a uniform tensegrity module. Inspired by the movement of worms in nature, an undulating shape change of the system is targeted to generate locomotion. The shape changeability of an exemplary tensegrity module due to internal actuation is examined in simulations and experiments. A prototype consisting of these tensegrity modules is manufactured and the locomotion principle is verified in experiments. Comparing to existing prototypes this approach enables an enhanced compliance due to the modular assembly of tensegrity structures. KW - Mobile robots KW - motion control Y1 - 2021 SN - 978-1-7281-7713-7 U6 - https://doi.org/10.1109/robosoft51838.2021.9479193 SP - 358 EP - 363 PB - IEEE ER - TY - JOUR A1 - Schorr, Philipp A1 - Böhm, Valter A1 - Zentner, Lena A1 - Zimmermann, Klaus T1 - Motion characteristics of a vibration driven mobile tensegrity structure with multiple stable equilibrium states JF - Journal of Sound and Vibration N2 - A novel type of a vibration driven motion system based on a compliant tensegrity structure with multiple stable equilibrium states is considered. These equilibrium configurations correspond to different prestress states with different dynamical properties. Therefore, the motion characteristics can be varied by changing the equilibrium state. For the application in the fields of mobile robotics, these discrete adjustable dynamics are advantageous. The vibration modes of the structure as well as the corresponding motion characteristics of the system can be adapted to the given environmental conditions in order to ensure a reliable motion. In this paper, dynamical investigations of an exemplary two-dimensional multistable tensegrity structure are considered. For the chosen parameter values the structure features two relevant equilibrium configurations. The resulting motion system is in contact to a horizontal plane due to gravity and the actuation is realized by the harmonic variation of the length of a single tensioned member. The motion of the system is simulated for various actuation frequencies with the different equilibrium states as an initial configuration. A uniaxial or a planar movement occurs depending on the selection of the actuated member within the tensegrity structure. The steady state motion is evaluated regarding motion characteristics like the steady state velocity. Moreover, the influences on the motion behavior caused by the different equilibrium states as an initial condition are emphasized. (C) 2018 Elsevier Ltd. All rights reserved. KW - Compliant tensegrity structure KW - LOCOMOTION KW - Multistability KW - Vibration driven motion Y1 - 2018 U6 - https://doi.org/10.1016/j.jsv.2018.09.019 VL - 437 IS - December SP - 198 EP - 208 PB - Elsevier ER - TY - CHAP A1 - Schorr, Philipp A1 - Ebnet, Markus A1 - Zimmermann, Klaus A1 - Böhm, Valter ED - Awrejcewicz, Jan T1 - Dynamic Investigation of a Rolling Locomotion System Based on a Tensegrity Structure with Spatially Curved Compressed Members T2 - Perspectives in Dynamical Systems I Applications : DSTA Łódź Poland December 6 - 9 2021. - (Springer Proceedings in Mathematics & Statistics ; Bd. 453) N2 - In this paper a compliant tensegrity structure based on spatially curved compressed members is presented. Due to an internal variation of the prestress state the shape of the structure can be controlled. In particular, a modification of a cylindrical outer shape to a conical form is achieved. Regarding to the applications in mobile robotics this approach enables a steerable two-dimensional rolling locomotion system. Beside the consideration of the underlying non-holonomic constraints a simplified mechanical model an the corresponding equations of motion are derived for a predefined actuation principle. Various numerical simulations are evaluated focusing on the corresponding locomotion behavior. Based on these results a reliable actuation strategy to navigate in two dimensions is proposed. KW - Tensegrity KW - Mobile robotics KW - Non-holonomic Constraints Y1 - 2024 SN - 978-3-031-56491-8 U6 - https://doi.org/10.1007/978-3-031-56492-5_32 SP - 437 EP - 449 PB - Springer International Publishing CY - Cham ER - TY - JOUR A1 - Chavez Vega, Jhohan Harvey A1 - Böhm, Valter A1 - Becker, Tatiana I. A1 - Gast, Simon A1 - Zeidis, Igor A1 - Zimmermann, Klaus T1 - Actuators based on a controlled particle-matrix interaction in magnetic hybrid materials for applications in locomotion and manipulation systems JF - Physical Sciences Reviews N2 - The paper deals with the investigation of magneto-sensitive elastomers (MSE) and their application in technical actuator systems. MSE consist of an elastic matrix containing suspended magnetically soft and/or hard particles. Additionally, they can also contain silicone oil, graphite particles, thermoplastic components, etc., in various concentrations in order to tune specific properties such as viscosity, conductivity and thermoelasticity, respectively. The focuses of investigations are the beneficial properties of MSE in prototypes for locomotion and manipulation purposes that possess an integrated sensor function. The research follows the principle of a model-based design, i.e. the working steps are ideation, mathematical modelling, material characterization as well as building first functional models (prototypes). The developed apedal (without legs) and non-wheeled locomotion systems use the interplay between material deformations and the mechanical motion in connection with the issues of control and stability. Non-linear friction phenomena lead to a monotonous forward motion of the systems. The aim of this study is the design of such mechanical structures, which reduce the control costs. The investigations deal with the movement and control of ‘intelligent’ mechanisms, for which the magnetically field-controlled particle-matrix interactions provide an appropriate approach. The presented grippers enclose partially gripped objects, which is an advantage for handling sensitive objects. Form-fit grippers with adaptable contour at the contact area enable a uniform pressure distribution on the surface of gripped objects. Furthermore, with the possibility of active shape adaptation, objects with significantly differing geometries can be gripped. To realise the desired active shape adaptation, the effect of field-induced plasticity of MSE is used. The first developed prototypes mainly confirm the functional principles as such without direct application. For this, besides the ability of locomotion and manipulation itself, further technological possibilities have to be added to the systems. The first steps are therefore being taken towards integrated MSE based adaptive sensor systems. KW - apedal locomotion systems KW - field-controlled particle-matrix interaction KW - field-induced plasticity KW - form-fit gripper KW - integrated sensor-actuator systems KW - magneto-sensitive elastomer Y1 - 2020 U6 - https://doi.org/10.1515/psr-2019-0087 VL - 7 IS - 11 SP - 1263 EP - 1290 PB - de Gruyter ER - TY - JOUR A1 - Chavez Vega, Jhohan Harvey A1 - Schorr, Philipp A1 - Kaufhold, Tobias A1 - Zentner, Lena A1 - Zimmermann, Klaus A1 - Böhm, Valter T1 - Influence of Elastomeric Tensioned Members on the Characteristics of Compliant Tensegrity Structures in Soft Robotic Applications JF - Procedia Manufacturing N2 - The use of mechanically prestressed compliant structures in soft robotics is a recently discussed topic. Tensegrity structures, consisting of a set of rigid disconnected compressed members connected to a continuous net of prestressed elastic tensioned members build one specific class of these structures. Robots based on these structures have manifold shape changing abilities and can adapt their mechanical properties reversibly by changing of their prestress state according to specific tasks. In the paper selected aspects on the potential use of elastomer materials in these structures are discussed with the help of theoretical analysis. Therefore, a selected basic tensegrity structure with elastomer members is investigated focusing on the stiffness and shape changing ability in dependence of the nonlinear hyperelastic behavior of the used elastomer materials. The considered structure is compared with a conventional tensegrity structure with linear elastic tensioned members. Finally, selected criterions for the advantageous use of elastomer materials in compliant tensegrity robots are discussed. KW - compliant tensegrity structures KW - soft robotics KW - elastomers Y1 - 2020 U6 - https://doi.org/10.1016/j.promfg.2020.11.048 SN - 2351-9789 VL - 52 SP - 289 EP - 294 PB - Elsevier ER - TY - JOUR A1 - Chavez Vega, Jhohan Harvey A1 - Ziolkowski, Marek A1 - Schorr, Philipp A1 - Spiess, Lothar A1 - Böhm, Valter A1 - Zimmermann, Klaus T1 - A method to approach constant isotropic permeabilities and demagnetization factors of magneto-rheological elastomers JF - Journal of Magnetism and Magnetic Materials N2 - The use of non-conventional materials is nowadays of much interest in scientific community. Magneto-rheological elastomers are hybrid materials, which in presence of magnetic fields state a change in their mechanical properties. They are composed by an elastomeric matrix with embedded magnetic particles. One of the most attractive features of these materials is that as soon as the magnetic field is removed from the material, the original mechanical properties are completely recovered, with negligible differences in comparison to the original state. This paper focuses on the study of magnetic characteristics of these smart materials, such as relative permeability and demagnetizing factors, for samples with different volume concentration of ferromagnetic particles. KW - Demagnetization factor KW - Finite element simulations KW - Magneto-rheological elastomer KW - Relative permeability KW - Static magnetic field Y1 - 2021 U6 - https://doi.org/10.1016/j.jmmm.2021.167742 VL - 527 PB - Elsevier ER - TY - CHAP A1 - Böhm, Valter A1 - Schorr, Philipp A1 - Feldmeier, T. A1 - Chavez Vega, Jhohan Harvey A1 - Henning, S. A1 - Zimmermann, Klaus A1 - Zentner, Lena T1 - An Approach to Robotic End Effectors Based on Multistable Tensegrity Structures T2 - New Trends in Mechanism and Machine Science: 8th European Conference on Mechanism Science (EuCoMeS), 2020 N2 - In this paper compliant multistable tensegrity structures with discrete variable stiffness are investigated. The different stiffness states result from the different prestress states of these structures corresponding to the equilibrium configurations. Three planar tensegrity mechanisms with two stable equilibrium configurations are considered exemplarily. The overall stiffness of these structures is characterized by investigations with regard to their geometric nonlinear static behavior. Dynamical analyses show the possibility of the change between the equilibrium configurations and enable the derivation of suitable actuation strategies. KW - Compliant tensegrity structure KW - Multiple states of self-equilibrium KW - Variable stiffness Y1 - 2020 U6 - https://doi.org/10.1007/978-3-030-55061-5_53 SP - 470 EP - 478 PB - Springer ER - TY - JOUR A1 - Becker, Tatiana I. A1 - Böhm, Valter A1 - Chavez Vega, Jhohan Harvey A1 - Odenbach, Stefan A1 - Raikher, Yuriy L. A1 - Zimmermann, Klaus T1 - Magnetic-field-controlled mechanical behavior of magneto-sensitive elastomers in applications for actuator and sensor systems JF - Archive of Applied Mechanics N2 - The development of actuator and sensor systems with complex adaptive behavior and operating sensitivity is one of the actual scientific challenges. Smart materials like magneto-sensitive elastomers (MSEs) offer great potential for designing such intelligent devices, because they possess unique magnetic-field-dependent properties. The present paper deals with investigations of the free and forced vibrational behavior displayed by cantilever beams of MSEs containing magnetically soft particles in a uniform magnetic field. It is shown experimentally as well as theoretically that the first bending eigenfrequency of MSE beams depends strongly on the strength of an applied magnetic field. The proposed magneto-mechanical model is based on the vibrational dynamics of thin rods and predicts reliably the amplitude–frequency characteristics depending on the geometric configuration of the MSE and its material parameters. It is found that the vibration response of an MSE beam under kinematic excitation of its base can be modified indirectly by a magnetic field control due to the change of the vibration characteristics. As a result, the resonance can occur in different ranges of the excitation frequency. The dependencies of the amplification ratio on the excitation frequency are obtained experimentally and compared with the result provided by the theoretical model. Moreover, investigations on the potential use of the field-induced plasticity effect of MSEs in form-fit gripper applications are presented. This effect can be used to realize shape adaptable system parts. It is found that the mechanical properties of each component and its concentration within the mixture have an impact on the mechanical behavior of the whole MSE compound. Such parameters as the strength of magnetic field and geometry of the MSE sample have influence on the quality of shape adaptation. The evidence presented provides a good basis for the realization of MSE-based actuator and sensor systems with adaptable sensitivity. Y1 - 2019 U6 - https://doi.org/10.1007/s00419-018-1477-4 VL - 89 IS - 1 SP - 133 EP - 152 PB - Springer Nature ER - TY - JOUR A1 - Prem, Nina A1 - Chavez Vega, Jhohan Harvey A1 - Böhm, Valter A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. A1 - Zimmermann, Klaus T1 - Properties of Polydimethylsiloxane and Magnetoactive Polymers with Electroconductive Particles JF - Macromolecular Chemistry and Physics N2 - Magnetoactive polymers are intelligent materials whose mechanical and electrical characteristics are reversibly influenced by external magnetic stimuli. They consist of a highly elastic polymer matrix in which magnetically soft and/or hard particles are distributed by means of special fabrication processes. In addition to ferromagnetic particles such as carbonyl iron powder, electrically conductive particles may also be embedded into the polymer matrix. After characterizing a range of compounds, this work focuses on a comparison of the electrical properties and the suitability of various materials for applications, with particular emphasis on integration into 3D and 6D printing processes. 6D printing is based on the selective positioning of particles in a 3D polymer matrix with a further three degrees of freedom for a graduated dispersion of the particles at certain points and in desired directions. The aim is therefore to ensure that the polymers containing electroconductive tracks have the best possible electrical properties, that is, low resistivity but are still capable of being printed. A comparison between the traditionally used compounds containing graphite and carbon black is made for the first time. This latter is found to be greatly superior both in terms of electrical conductivity and applicability to 3D printing and 6D printing. KW - 3D printing KW - 6D printing KW - carbon black KW - composites KW - electroconductive particles KW - graphite KW - magnetoactive polymers KW - polydimethylsiloxane KW - STRAIN, *MRU Y1 - 2018 U6 - https://doi.org/10.1002/macp.201800222 VL - 219 IS - 18 PB - Wiley ER - TY - CHAP A1 - Chavez Vega, Jhohan Harvey A1 - Schorr, Philipp A1 - Scharff, Moritz A1 - Schale, Florian A1 - Böhm, Valter A1 - Zimmermann, Klaus T1 - Towards Magneto-Sensitive Elastomers Based End-Effectors for Gripping Application Technologies T2 - 2019 IEEE International Conference on Mechatronics (ICM), 18-20 March 2019, Ilmenau, Germany N2 - Nowadays, the demands in engineering systems become more challenging and the use of conventional materials for certain applications is not suitable. This issue encourages the investigation of novel and innovative materials in soft robotics field. A promising approach is the consideration of magneto-sensitive elastomers (MSE). These materials enable a useful adaptability responding to their mechanical properties. By applying a static magnetic field, the static and dynamic characteristics can be tuned. However, currently the knowledge about the correlations are not satisfying and the resulting material properties can only be predicted approximately with the use of time-expensive simulations regarding to the nano scale. Therefore, feasible material simulations of the description of the mechanical behavior are necessary. In this paper experimental studies of the influence of a static magnetic field on the mechanical properties and shape adaptability of MSE are presented. Furthermore, based on these results a simulation for the material behavior is executed. These results can be implemented into further simulations for various MSE exemplars. KW - End effectors KW - field-induced plasticity KW - finite-element simulation KW - Iron KW - Magnetomechanical effects KW - magneto-sensitive elastomer KW - Oils KW - SHAPE KW - Soft magnetic materials KW - soft robotics KW - Static magnetic field Y1 - 2019 U6 - https://doi.org/10.1109/ICMECH.2019.8722922 VL - 1 SP - 217 EP - 222 PB - IEEE ER - TY - CHAP A1 - Chavez Vega, Jhohan Harvey A1 - Böhm, Valter A1 - Becker, Tatiana I. A1 - Gast, Simon A1 - Zeidis, Igor A1 - Zimmermann, Klaus ED - Odenbach, Stefan T1 - Actuators based on a controlled particlematrix interaction in magnetic hybrid materials for applications in locomotion and manipulation systems T2 - Magnetic Hybrid-Materials: Multi-scale modelling synthesis and applications N2 - The paper deals with the investigation of magneto-sensitive elastomers(MSE) and their application in technical actuator systems. MSE consist of an elasticmatrix containing suspended magnetically soft and/or hard particles. Additionally,they can also contain silicone oil, graphite particles, thermoplastic components, etc.,in various concentrations in order to tune specific properties such as viscosity, con-ductivity and thermoelasticity, respectively. The focuses of investigations are thebeneficial properties of MSE in prototypes for locomotion and manipulation purposesthat possess an integrated sensor function. The research follows the principle of amodel-based design, i.e. the working steps are ideation, mathematical modelling,material characterization as well as building first functional models (prototypes). Thedeveloped apedal (without legs) and non-wheeled locomotion systems use the inter-play between material deformations and the mechanical motion in connection with theissues of control and stability. Non-linear friction phenomena lead to a monotonousforward motion of the systems. The aim of this study is the design of such mechanicalstructures, which reduce the control costs. The investigations deal with the movementand control of‘intelligent’mechanisms, for which the magnetically field-controlledparticle-matrix interactions provide an appropriate approach. The presented grippersenclose partially gripped objects, which is an advantage for handling sensitive objects.Form-fit grippers with adaptable contour at the contact area enable a uniform pressuredistribution on the surface of gripped objects. Furthermore, with the possibility ofactive shape adaptation, objects with significantly differing geometries can be gripped.To realise the desired active shape adaptation, the effect of field-induced plasticity ofMSE is used. The first developed prototypes mainly confirm the functional principles assuch without direct application. For this, besides the ability of locomotion andmanipulation itself, further technological possibilities have to be added to the systems. KW - apedal locomotion systems KW - field-controlled particle-matrix interaction KW - field-induced plasticity KW - form-fit gripper KW - integrated sensor-actuator systems KW - magneto-sensitive elastomer Y1 - 2021 SN - 9783110569636 U6 - https://doi.org/10.1515/9783110569636-027 N1 - Zuerst erschienen in: Physical Sciences Reviews, 2020, pp. 20190087 SP - 653 EP - 680 PB - De Gruyter CY - Berlin ER - TY - CHAP A1 - Kouakouo, S. A1 - Böhm, Valter A1 - Zimmermann, Klaus T1 - Analyses of apedal locomotion systems based on ferroelastomers T2 - Proceedings I of the 28st Conference STUDENT EEICT 2022: General papers N2 - In this paper, the movement behavior of amoeboid locomotion system is investigated and the theoretical proof of the locomotion of the system is provided with the finite element method. It is shown that not only the speed of locomotion but also its direction can be influenced by the drive frequency. Depending on the drive frequency, a movement from the home position and a subsequent movement in opposite directions can be achieved. In addition, high speeds of movement can be achieved in a limited frequency range. KW - Technical Mechanics KW - Legless Locomotion System KW - Amoeboid Robot Y1 - 2023 UR - http://www.nusl.cz/ntk/nusl-524810 SN - 978-80-214-6029-4 SP - 447 EP - 451 PB - Vysoké učení technické v Brně, Fakulta elektrotechniky a komunikačních technologií ER - TY - JOUR A1 - Schümann, Malte A1 - Morich, J. A1 - Kaufhold, Tobias A1 - Böhm, Valter A1 - Zimmermann, Klaus A1 - Odenbach, Stefan T1 - A mechanical characterisation on multiple timescales of electroconductive magnetorheological elastomers JF - Magnetism and Magnetic Materials N2 - Magnetorheological elastomers are a type of smart hybrid material which combines elastic properties of a soft elastomer matrix with magnetic properties of magnetic micro particles. This leads to a material with magnetically controllable mechanical properties of which the magnetorheological effect is the best known. The addition of electroconductive particles to the polymer mix adds electrical properties to the material behaviour. The resulting electrical resistance of the sample can be manipulated by external magnetic fields and mechanical loads. This results in a distinct interplay of mechanical, electrical and magnetic effects with a highly complex time behaviour. In this paper a mechanical characterisation on multiple time scales was conducted to get an insight on the short and long-term electrical and mechanical behaviour of this novel material. The results show a complex resistivity behaviour on several timescales, sensitive to magnetic fields and strain velocity. The observed material exhibits fatigue and relaxation behaviour, whereas the magnetorheological effect appears not to interfere with the piezoresistive properties. Y1 - 2018 U6 - https://doi.org/10.1016/j.jmmm.2018.01.029 VL - 453 IS - May SP - 198 EP - 205 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 - TY - JOUR A1 - Zimmermann, Klaus A1 - Chavez Vega, Jhohan Harvey A1 - Becker, Tatiana I. A1 - Witte, Hartmut A1 - Schilling, Cornelius A1 - Köhring, Sebastian A1 - Böhm, Valter A1 - Monkman, Gareth J. A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Lutz, I. I. A1 - Merker, Lukas T1 - An approach to a form-adaptive compliant gripper element based on magneto-sensitive elastomers with a bioinspired sensorized surface JF - Problems of Mechanics Y1 - 2019 SN - 1512-0740 VL - 75 IS - 2 SP - 23 EP - 38 PB - Georgian Technical University CY - Tbilisi ER - TY - GEN A1 - Chavez Vega, Jhohan Harvey A1 - Böhm, Valter A1 - Yin, J. A1 - Becker, Tatiana I. A1 - Köhring, Sebastian A1 - Monkman, Gareth J. A1 - Odenbach, Stefan A1 - Zimmermann, Klaus T1 - Field induced plasticity of magneto-sensitive elastomers for gripping technology applications T2 - 6th Colloquium of SPP 1681, Benediktbeuern, 26. - 28.09.2018 : Book of Abstracts Y1 - 2018 SP - 16 EP - 17 ER - TY - JOUR A1 - Becker, Tatiana I. A1 - Böhm, Valter A1 - Schale, Florian A1 - Zimmermann, Klaus T1 - Vibrating sensor unit made of a magnetoactive elastomer with field-adjustable characteristics JF - Journal of Magnetism and Magnetic Materials N2 - The present work deals with the investigation of the oscillatory behavior displayed by a vibrating sensor unit made of a magnetoactive elastomer (MAE). Since this type of smart materials consists of an elastic matrix and micro-magnetic particles, it reveals exceptional magnetic-field-dependent material properties. The forced vibration response under the bending of the MAE unit subjected to in-plane harmonic kinematic excitation of the housing is studied. It is found that the amplitude-frequency characteristics of the MAE unit can be changed considerably by means of an external homogeneous magnetic field. With and without applied field, the unit displays different steady-state responses for the same excitation, and the resonance occurs at various ranges of the excitation frequency. The nonlinear phenomenon of the resonance hysteresis is observed depending on whether the excitation frequency increases or decreases. It is shown that the MAE vibrations can be detected based on the magnetic field distortion measurements. The presented prototype of the MAE-based vibrating unit with field-adjustable “configuration” can be potentially implemented for realization of acceleration sensor systems with adaptive sensitivity. Y1 - 2020 U6 - https://doi.org/10.1016/j.jmmm.2019.166196 VL - 498 IS - March PB - Elsevier ER - TY - GEN A1 - Chavez Vega, Jhohan Harvey A1 - Böhm, Valter A1 - Scharff, Moritz A1 - Prem, Nina A1 - Monkman, Gareth J. A1 - Becker, Tatiana I. A1 - Günther, L. A1 - Alencastre, Jorge H. A1 - Grieseler, R. A1 - Zimmermann, Klaus T1 - Magneto-active elastomer as viscoelastic foundation material for artificial tactile sensors with tuneable properties T2 - Book of Abstracts of the 16th German Ferrofluid Workshop, Braunschweig, 18.-20.07.2018 Y1 - 2018 SP - 16 EP - 17 ER -