TY - CHAP A1 - Chavez Vega Jhohan, A1 - Scharff, Moritz A1 - Helbig, Thomas A1 - Alencastre, Jorge H. A1 - Böhm, Valter A1 - Behn, Carsten ED - Kecskeméthy, Andrés T1 - Analysis of the Dynamic Behavior of Beams Supported by a Visco-Elastic Foundation in Context to Natural Vibrissa T2 - Interdisciplinary Applications of Kinematics : Proceedings of the Third International Conference (IAK) N2 - Rodents use their mystacial vibrissae, e.g., to recognize the shape or determine the surface texture of an object. The vibrissal sensory system consists of two components: the hair shaft and the follicle-sinus complex (FSC). Both components affect the collection of information, but the impacts of the different properties are not completely clear. Borrowing the natural example, the goal is to design a powerful artificial sensor. The influence of a continuous visco-elastic support is analyzed for an artificial sensor following hypotheses about the FSC. Starting with a theoretical treatment of this scenario, the vibrissa is modeled as an Euler-Bernoulli bending beam with a partially continuous visco-elastic support. The numerical simulations are validated by experiments. Using a steel strip as a technical vibrissa and a magneto-sensitive elastomer (MSE) as representation of the artificial continuous visco-elastic support, FSC respectively, the first resonance frequency is determined. Y1 - 2019 SN - 978-3-030-16422-5 U6 - https://doi.org/10.1007/978-3-030-16423-2_5 VL - 71 SP - 51 EP - 59 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 - Schorr, Philipp A1 - Chavez Vega, Jhohan Harvey A1 - Zentner, Lena A1 - Böhm, Valter T1 - Reconfiguration of planar quadrilateral linkages utilizing the tensegrity principle JF - Mechanism and machine theory N2 - The development of reconfigurable planar four-bar linkages by applying the tensegrity principle is considered. Conventional quadrilateral linkages enable two operation modes differing in the kinematic behavior. However, a change between these states is not possible due to the geometric constraints. To enable a reconfiguration between the different modes one-sided limited nonholonomic constraints are introduced in this work. This issue is realized by applying ropes that cannot resist compression. However, to guarantee an appropriate load case in operation a prestress within the mechanism is required. Hence, the linkage is extended to a tensegrity-based mechanism. The structural dynamics are derived using the LAGRANGE formalism and the structural behavior is evaluated using numerical simulations. Furthermore, a prototype of an exemplary tensegrity-based mechanism is manufactured and experiments regarding the mechanical properties, in particular the reconfiguration, are performed. The results suggest the potential benefit of applying the tensegrity principle within conventional planar four-bar linkages. KW - CONFIGURATION SYNTHESIS KW - MECHANISMS KW - Multibody dynamics KW - Planar four-bar linkage KW - Reconfiguration KW - Tensegrity-based mechanism Y1 - 2021 U6 - https://doi.org/10.1016/j.mechmachtheory.2020.104172 IS - 156 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 - GEN A1 - Chavez Vega, Jhohan Harvey A1 - Henning, S. A1 - Zentner, Lena A1 - Böhm, Valter T1 - Soft tensegrity structures with variable stiffness and shape changing ability T2 - Annual Meeting of the DFG Priority Programme Soft Material Robotic Systems, SPP2100, 02-04. März 2020, Schneverdingen Y1 - 2020 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 - Schorr, Philipp A1 - Chavez Vega, Jhohan Harvey A1 - Zentner, Lena A1 - Böhm, Valter ED - Zentner, Lena ED - Strehle, Steffen T1 - Reconfigurable Planar Quadrilateral Linkages Based on the Tensegrity Principle T2 - Microactuators, Microsensors and Micromechanisms, MAMM, 2020 N2 - A feasible possibility to develop planar reconfigurable mechanisms is introduced in this work. Applying the tensegrity principle to common four-bar linkages allows a controllable change between two configurations of the mechanism. These two states correspond to different working spaces which vary regarding to the kinematic and mechanical properties. Therefore, the reconfiguration of the mechanism enables two different operation modes. Hence, this kind of mechanism enables the advantageous properties of conventional linkages with an additional enhanced adaptability of the kinematic and mechanic behavior. Beside the conceptual design of such tensegrity-based mechanisms, a reconfigurable four-bar parallel linkage is considered exemplarily. Numerical simulations are evaluated focusing on the kinematic behavior and the structural mechanics of this mechanism. Especially the reconfiguration of the mechanism by changing between two different working spaces is considered. The simulation results clarify the benefit of utilizing the tensegrity principle in mechanism theory. Adding only a few members to the original linkage enables a reconfigurable mechanism with comparable complexity. KW - Planar four-bar linkage KW - Reconfigurable mechanisms KW - tensegrity Y1 - 2021 SN - 978-3-030-61651-9 U6 - https://doi.org/10.1007/978-3-030-61652-6_5 SP - 48 EP - 57 PB - Springer International Publishing CY - Cham 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 - 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 - 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 -