@inproceedings{BoehmSchorrFeldmeieretal., author = {B{\"o}hm, Valter and Schorr, Philipp and Feldmeier, T. and Chavez Vega, Jhohan Harvey and Henning, S. and Zimmermann, Klaus and Zentner, Lena}, title = {An Approach to Robotic End Effectors Based on Multistable Tensegrity Structures}, series = {New Trends in Mechanism and Machine Science: 8th European Conference on Mechanism Science (EuCoMeS), 2020}, booktitle = {New Trends in Mechanism and Machine Science: 8th European Conference on Mechanism Science (EuCoMeS), 2020}, publisher = {Springer}, doi = {10.1007/978-3-030-55061-5_53}, pages = {470 -- 478}, abstract = {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.}, language = {en} } @misc{ChavezVegaHenningZentneretal., author = {Chavez Vega, Jhohan Harvey and Henning, S. and Zentner, Lena and B{\"o}hm, Valter}, title = {Soft tensegrity structures with variable stiffness and shape changing ability}, series = {Annual Meeting of the DFG Priority Programme Soft Material Robotic Systems, SPP2100, 02-04. M{\"a}rz 2020, Schneverdingen}, journal = {Annual Meeting of the DFG Priority Programme Soft Material Robotic Systems, SPP2100, 02-04. M{\"a}rz 2020, Schneverdingen}, language = {en} } @article{BeckerBoehmChavezVegaetal., author = {Becker, Tatiana I. and B{\"o}hm, Valter and Chavez Vega, Jhohan Harvey and Odenbach, Stefan and Raikher, Yuriy L. and Zimmermann, Klaus}, title = {Magnetic-field-controlled mechanical behavior of magneto-sensitive elastomers in applications for actuator and sensor systems}, series = {Archive of Applied Mechanics}, volume = {89}, journal = {Archive of Applied Mechanics}, number = {1}, publisher = {Springer Nature}, doi = {10.1007/s00419-018-1477-4}, pages = {133 -- 152}, abstract = {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.}, language = {en} } @article{PremChavezVegaBoehmetal., author = {Prem, Nina and Chavez Vega, Jhohan Harvey and B{\"o}hm, Valter and Sindersberger, Dirk and Monkman, Gareth J. and Zimmermann, Klaus}, title = {Properties of Polydimethylsiloxane and Magnetoactive Polymers with Electroconductive Particles}, series = {Macromolecular Chemistry and Physics}, volume = {219}, journal = {Macromolecular Chemistry and Physics}, number = {18}, publisher = {Wiley}, doi = {10.1002/macp.201800222}, abstract = {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.}, language = {en} } @inproceedings{ChavezVegaSchorrScharffetal., author = {Chavez Vega, Jhohan Harvey and Schorr, Philipp and Scharff, Moritz and Schale, Florian and B{\"o}hm, Valter and Zimmermann, Klaus}, title = {Towards Magneto-Sensitive Elastomers Based End-Effectors for Gripping Application Technologies}, series = {2019 IEEE International Conference on Mechatronics (ICM), 18-20 March 2019, Ilmenau, Germany}, volume = {1}, booktitle = {2019 IEEE International Conference on Mechatronics (ICM), 18-20 March 2019, Ilmenau, Germany}, publisher = {IEEE}, doi = {10.1109/ICMECH.2019.8722922}, pages = {217 -- 222}, abstract = {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.}, language = {en} } @inproceedings{SchorrChavezVegaZentneretal., author = {Schorr, Philipp and Chavez Vega, Jhohan Harvey and Zentner, Lena and B{\"o}hm, Valter}, title = {Reconfigurable Planar Quadrilateral Linkages Based on the Tensegrity Principle}, series = {Microactuators, Microsensors and Micromechanisms, MAMM, 2020}, booktitle = {Microactuators, Microsensors and Micromechanisms, MAMM, 2020}, editor = {Zentner, Lena and Strehle, Steffen}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-61651-9}, doi = {10.1007/978-3-030-61652-6_5}, pages = {48 -- 57}, abstract = {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.}, language = {en} } @incollection{ChavezVegaBoehmBeckeretal., author = {Chavez Vega, Jhohan Harvey and B{\"o}hm, Valter and Becker, Tatiana I. and Gast, Simon and Zeidis, Igor and Zimmermann, Klaus}, title = {Actuators based on a controlled particlematrix interaction in magnetic hybrid materials for applications in locomotion and manipulation systems}, series = {Magnetic Hybrid-Materials: Multi-scale modelling synthesis and applications}, booktitle = {Magnetic Hybrid-Materials: Multi-scale modelling synthesis and applications}, editor = {Odenbach, Stefan}, publisher = {De Gruyter}, address = {Berlin}, isbn = {9783110569636}, doi = {10.1515/9783110569636-027}, pages = {653 -- 680}, abstract = {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.}, language = {en} } @inproceedings{SchaefferHerrmannBoehm, author = {Schaeffer, Leon and Herrmann, David and B{\"o}hm, Valter}, title = {Preliminary theoretical considerations of a hand orthosis based on a prestressed, compliant structure}, series = {Proceedings of the 2023 International Symposium on Medical Robotics (ISMR), Atlanta, 19-21 April 2023}, booktitle = {Proceedings of the 2023 International Symposium on Medical Robotics (ISMR), Atlanta, 19-21 April 2023}, publisher = {IEEE}, doi = {10.1109/ISMR57123.2023.10130230}, pages = {1 -- 7}, abstract = {In the treatment of hand injuries in the context of orthopedic care, movable hand orthoses are used in many cases. Early motion therapy is in most cases advantageous for adequate, rapid, and successful long-term healing of the hand. Conventional mobile hand orthoses can only be used for movement therapy to a limited extent since they represent the wrist as a simple rotating joint and neglect the complexity of the movement possibilities of the hand. In this paper, a novel concept for movable hand orthoses based on prestressed compliant structures is presented. The advantage with this concept is that it replicates the multiaxial motion capabilities without the need for conventional joints. Besides the derivation and description of the concept, a first three-dimensional CAD design is shown. Additionally, the next planned steps in the development of such a novel dynamic hand orthosis are described.}, language = {en} } @inproceedings{KouakouoBoehmZimmermann, author = {Kouakouo, S. and B{\"o}hm, Valter and Zimmermann, Klaus}, title = {Analyses of apedal locomotion systems based on ferroelastomers}, series = {Proceedings I of the 28st Conference STUDENT EEICT 2022: General papers}, booktitle = {Proceedings I of the 28st Conference STUDENT EEICT 2022: General papers}, publisher = {Vysok{\´e} učen{\´i} technick{\´e} v Brně, Fakulta elektrotechniky a komunikačn{\´i}ch technologi{\´i}}, isbn = {978-80-214-6029-4}, pages = {447 -- 451}, abstract = {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.}, language = {en} } @inproceedings{SchaefferHerrmannBoehm, author = {Schaeffer, Leon and Herrmann, David and B{\"o}hm, Valter}, title = {Theoretical considerations on a 2D compliant tensegrity joint in context of a biomedical application}, series = {Engineering for a changing world : 60th ISC, Ilmenau Scientific Colloquium, Technische Universit{\"a}t Ilmenau, September 4-8, 2023}, booktitle = {Engineering for a changing world : 60th ISC, Ilmenau Scientific Colloquium, Technische Universit{\"a}t Ilmenau, September 4-8, 2023}, publisher = {Technische Universit{\"a}t Ilmenau}, address = {Ilmenau}, doi = {10.22032/dbt.58879}, pages = {1 -- 15}, abstract = {In this paper, a two-dimensional compliant tensegrity joint was investigated for potential biomedical applications such as orthotics or exoskeletons. The structure consists of two compressed members connected by five compliant tensioned members. The concept is based on the tensegrity principle, which allows the realization of dynamic orthoses without conventional hinge joints. Another advantage is the adaptability to the individual needs of the patient through a suitable design of the structure and the careful selection of the characteristics of the elements. Using geometric nonlinear analysis, the mechanical behavior of the structure was investigated, focusing on mechanical compliance. The main objective was to determine the influence of the initial length and stiffness of the tensioned members and the influence of the magnitude of external forces on the overall stiffness of the movable member of the structure. The results highlight the significant impact of member parameters on the structure's stiffness and movability under varying load magnitudes. The research laid the foundation for future development of dynamic orthoses based on this structure.}, language = {en} } @article{SchaefferHerrmannSchmausseretal., author = {Schaeffer, Leon and Herrmann, David and Schmausser, Theresa and Liebrecht, Melanie and Rambach, Felix and B{\"o}hm, Valter}, title = {Theoretische Untersuchungen zu einer neuartigen Handorthese : [Kurzfassung des Tagungsbeitrags]}, series = {10. IFToMM D-A-CH Konferenz 2024: 05./06. M{\"a}rz 2024, Universit{\"a}t Rostock.}, journal = {10. IFToMM D-A-CH Konferenz 2024: 05./06. M{\"a}rz 2024, Universit{\"a}t Rostock.}, doi = {10.17185/duepublico/81586}, language = {de} } @inproceedings{SchaefferHerrmannBoehm, author = {Schaeffer, Leon and Herrmann, David and B{\"o}hm, Valter}, title = {Preliminary considerations on the form-finding of a tensegrity joint to be used in dynamic orthoses}, series = {8th International Conference on Biomedical Engineering and Applications (ICBEA 2024), Tokio, 18-21. March 2024}, booktitle = {8th International Conference on Biomedical Engineering and Applications (ICBEA 2024), Tokio, 18-21. March 2024}, edition = {accepted paper}, publisher = {ACM}, language = {en} } @inproceedings{SchaefferHerrmannBoehm, author = {Schaeffer, Leon and Herrmann, David and B{\"o}hm, Valter}, title = {Theoretical Investigations on a Dynamic Hand Orthosis Based on a Prestressed Compliant Structure with Respect to Stiffness and Wrist-Forces}, series = {2024 International Symposium on Medical Robotics (ISMR), 03-05 June 2024, Atlanta, GA, USA}, booktitle = {2024 International Symposium on Medical Robotics (ISMR), 03-05 June 2024, Atlanta, GA, USA}, publisher = {IEEE}, issn = {2771-9049}, doi = {10.1109/ISMR63436.2024.10585860}, abstract = {Many currently available dynamic hand orthoses use articulated connections that have one degree of freedom, such as hinge joints. These orthoses are therefore only able to replicate the multiaxial range of motion of the human hand to a limited extent. A possible solution for replecating the multiaxial movements of the hand is the use of pre-stressed compliant structures as a basis for the orthoses. After a brief description of this concept, the two main first steps by the development, the so called form-finding and the wrist-joint force characterization by hand movements are explained with theoretical analysis based on the static Finite Element Method. The influence of the orthosis parameters, global stiffness and geometric dimensions as well as the influence of the wrist-joint position relative to the orthosis are discussed. Finally, the next planned development steps towards to the first prototype are outlined.}, language = {en} } @article{SchuemannMorichKaufholdetal., author = {Sch{\"u}mann, Malte and Morich, J. and Kaufhold, Tobias and B{\"o}hm, Valter and Zimmermann, Klaus and Odenbach, Stefan}, title = {A mechanical characterisation on multiple timescales of electroconductive magnetorheological elastomers}, series = {Magnetism and Magnetic Materials}, volume = {453}, journal = {Magnetism and Magnetic Materials}, number = {May}, publisher = {Elsevier}, doi = {10.1016/j.jmmm.2018.01.029}, pages = {198 -- 205}, abstract = {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.}, language = {en} } @article{ZimmermannBoehmBeckerTIetal., author = {Zimmermann, Klaus and B{\"o}hm, Valter and Becker T.I., and Chavez Vega, Jhohan Harvey and Kaufhold, Tobias and Monkman, Gareth J. and Sindersberger, Dirk and Diermeier, Andreas and Prem, Nina}, title = {Mechanical Characterization of the Field-Dependent Properties of Magnetoactive Polymers and Integrated Electrets for their Application in Soft Robotics}, series = {International Scientific Journal "Problems of Mechanics"}, volume = {69}, journal = {International Scientific Journal "Problems of Mechanics"}, number = {4}, issn = {1512-0740}, language = {en} } @inproceedings{HerrmannSchaefferZentneretal., author = {Herrmann, David and Schaeffer, Leon and Zentner, Lena and B{\"o}hm, Valter}, title = {Theoretische und experimentelle Voruntersuchungen von Manipulatoren auf Basis von nachgiebigen Tensegrity-Strukturen}, series = {9. IFToMM D-A-CH Konferenz, 16./17. M{\"a}rz 2023, Universit{\"a}t Basel}, booktitle = {9. IFToMM D-A-CH Konferenz, 16./17. M{\"a}rz 2023, Universit{\"a}t Basel}, publisher = {DuEPublico}, address = {Duisburg-Essen}, doi = {10.17185/duepublico/77397}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:465-20230314-164736-8}, abstract = {In this paper, two compliant tensegrity manipulators are presented and contrasted with respect to their mechanical pro- perties and deformation capability. They differ in their topology, in the way they are actuated and also in their mechanical compliance. The mechanical compliance of the first system is based on the elasticity of the tensioned segments, while the compressed segments are rigid. The second system is based on elementary units, which are themselves spatial tensegrity structures. In this system, both the tension and compressed segments are compliant. Actuation of the first system occurs by changing the length of the tensile segments. In the second system, the change in shape of the overall system is realized by changing the shape of the compliant compressed segments}, language = {de} } @article{ZimmermannChavezVegaBeckeretal., author = {Zimmermann, Klaus and Chavez Vega, Jhohan Harvey and Becker, Tatiana I. and Witte, Hartmut and Schilling, Cornelius and K{\"o}hring, Sebastian and B{\"o}hm, Valter and Monkman, Gareth J. and Prem, Nina and Sindersberger, Dirk and Lutz, I. I. and Merker, Lukas}, title = {An approach to a form-adaptive compliant gripper element based on magneto-sensitive elastomers with a bioinspired sensorized surface}, series = {Problems of Mechanics}, volume = {75}, journal = {Problems of Mechanics}, number = {2}, publisher = {Georgian Technical University}, address = {Tbilisi}, issn = {1512-0740}, pages = {23 -- 38}, language = {en} } @article{JahnBoehmZentner, author = {Jahn, Hannes and B{\"o}hm, Valter and Zentner, Lena}, title = {Analysis of deformation in tensegrity structures with curved compressed members}, series = {Meccanica}, journal = {Meccanica}, publisher = {Springer Nature}, issn = {0025-6455}, doi = {10.1007/s11012-024-01833-y}, pages = {12}, abstract = {AbstractTensegrity structures are prestressed structures consisting of compressed members connected by prestressed tensioned members. Due to their properties, such as flexibility and lightness, mobile robots based on these structures are an attractive subject of research and are suitable for space applications. In this work, a mobile robot based on a tensegrity structure with two curved members connected by eight tensioned strings is analyzed in terms of deformation in the curved members. Further, the difference in locomotion trajectory between the undeformed and deformed structure after the prestress is analyzed. For that, the theory of large deflections of rod-like structures is used. To determine the relationship between acting forces and the deformation, the structure is optimized using minimization algorithms in Python. The results are validated by parameter studies in FEM. The analysis shows that the distance between the two curved members significantly influences the structure's locomotion. It can be said that the deformation of the components significantly influences the locomotion of tensegrity structures and should be considered when analyzing highly compliant structures.}, language = {en} } @inproceedings{HerrmannSchaefferSchmittetal., author = {Herrmann, David and Schaeffer, Leon and Schmitt, Lukas and K{\"o}rber, Wolfgang and Merker, Lukas and Zentner, Lena and B{\"o}hm, Valter}, title = {Compliant Robotic Arm based on a Tensegrity Structure with x-shaped Members}, series = {2024 IEEE 7th International Conference on Soft Robotics (RoboSoft), San Diego, CA, USA. April 14-17, 2024}, booktitle = {2024 IEEE 7th International Conference on Soft Robotics (RoboSoft), San Diego, CA, USA. April 14-17, 2024}, publisher = {IEEE}, doi = {10.1109/RoboSoft60065.2024.10521941}, pages = {1047}, abstract = {The use of intrinsically compliant tensegrity structures in manipulation systems is an attractive research topic. In this paper a 3D compliant robotic arm based on a stacked tensegrity structure consisting of x-shaped rigid members is considered. The rigid members are interconnected by a net of prestressed, tensioned members with pronounced intrinsic elasticity and by inelastic tensioned members. The system's motion is achieved by length-change of the inelastic tensioned members. The operating principle of the system is discussed with the help of kinematic considerations and verified by experiments.}, language = {en} } @misc{RieffelHerrmannLehmannetal., author = {Rieffel, John and Herrmann, David and Lehmann, Lukas and Schaeffer, Leon and B{\"o}hm, Valter}, title = {Illuminating the morphological diversity of 2D tensegrity grids}, series = {MMT Symposium (Mechanism and Machine Theory Symposium): Book of Abstracts ; June 26-28, 2024. - Guimar{\~a}es, Portugal}, journal = {MMT Symposium (Mechanism and Machine Theory Symposium): Book of Abstracts ; June 26-28, 2024. - Guimar{\~a}es, Portugal}, number = {1. edition}, editor = {Flores, Paulo and Marques, Filipe and Da Rodrigues Silva, Mariana}, publisher = {Departamento de Engenharia Mec{\^a}nica, Universidade do Minho}, address = {Guimar{\~a}es, Portugal}, isbn = {978-989-33-6448-2}, pages = {457 -- 458}, language = {en} } @inproceedings{MerkerBoehmZentner, author = {Merker, Lukas and B{\"o}hm, Valter and Zentner, Lena}, title = {Modellbildung und Steifigkeitsanalyse eines nachgiebigen Tensegrity-{\"a}hnlichen Koppelelements}, series = {15. Kolloquium Getriebetechnik, 2023, Aachen}, booktitle = {15. Kolloquium Getriebetechnik, 2023, Aachen}, publisher = {Verlag Mainz}, address = {Aachen}, pages = {63 -- 66}, language = {en} } @misc{ChavezVegaBoehmYinetal., author = {Chavez Vega, Jhohan Harvey and B{\"o}hm, Valter and Yin, J. and Becker, Tatiana I. and K{\"o}hring, Sebastian and Monkman, Gareth J. and Odenbach, Stefan and Zimmermann, Klaus}, title = {Field induced plasticity of magneto-sensitive elastomers for gripping technology applications}, series = {6th Colloquium of SPP 1681, Benediktbeuern, 26. - 28.09.2018 : Book of Abstracts}, journal = {6th Colloquium of SPP 1681, Benediktbeuern, 26. - 28.09.2018 : Book of Abstracts}, pages = {16 -- 17}, language = {en} } @inproceedings{HerrmannSchaefferZentneretal., author = {Herrmann, David and Schaeffer, Leon and Zentner, Lena and B{\"o}hm, Valter}, title = {Theoretical considerations on 3D tensegrity joints for the use in manipulation systems}, series = {Engineering for a changing world : 60th ISC, Ilmenau Scientific Colloquium, Technische Universit{\"a}t Ilmenau, September 4-8, 2023}, booktitle = {Engineering for a changing world : 60th ISC, Ilmenau Scientific Colloquium, Technische Universit{\"a}t Ilmenau, September 4-8, 2023}, publisher = {Technische Universit{\"a}t Ilmenau}, address = {Ilmenau}, doi = {10.22032/dbt.58888}, pages = {1 -- 13}, abstract = {This paper presents a comprehensive analysis of a three-dimensional compliant tensegrity joint structure, examining its actuation, kinematics, and response to external loads. The study investigates a baseline configuration and two asymmetric variants of the joint. The relationship between the shape parameter and the parameters of the tensioned segments is derived, enabling the mathematical description of cable lengths for joint actuation. Geometric nonlinear static finite element simulations are performed to analyze the joint's response under various load conditions. The results reveal the joint's range of motion, the effect of different stiffness configurations, and its deformation behavior under external forces. The study highlights the asymmetric nature of the joint and its potential for targeted motion restriction. These findings advance the general understanding of the behavior of the considered tensegrity joint and provide valuable insights for their design and application in soft robotic systems.}, language = {en} } @inproceedings{HerrmannSchaefferMerkeretal., author = {Herrmann, David and Schaeffer, Leon and Merker, Lukas and Zentner, Lena and B{\"o}hm, Valter}, title = {An Approach to the Realization of Multistable Tensegrity Structures with Deformable Compressed Members}, series = {Microactuators, Microsensors and Micromechanisms : MAMM 2024.}, booktitle = {Microactuators, Microsensors and Micromechanisms : MAMM 2024.}, editor = {Nguyen, Duc-Nam and Tran, Ngoc Dang Khoa and van Huynh, Tuan and Ono, Takahito and van Nguyen, Hieu and Pandey, Ashok Kumar}, publisher = {Springer Nature}, address = {Cham}, isbn = {978-3-031-83356-4}, doi = {10.1007/978-3-031-83357-1_34}, pages = {343 -- 350}, abstract = {Within this paper a novel tensegrity-mechanism is described. The mechanism is based on a tensegrity principle with multiple states of self-equilibrium. The tensegrity mechanism is built upon a mechanical compliant tensegrity structure, consisting of tensioned and compressed members. The existence of the different states of self-equilibrium depends on the parameters of deformable compressed members with continuous or discontinuous load-displacement characteristic. The working principle of the mechanism and the mechanical compliance is verified by theoretical investigations. Therefore, in the first step, the deformable compressed members are analyzed separately. With the help of the subsequent following form-finding procedure the equilibrium configurations of the mechanism and their static stability are analyzed in dependence of the mechanical parameters of the compressed and tensioned members. As a specific application case, the use of the mechanism as a variable stiffness device is discussed.}, language = {en} } @misc{HerrmannSchaefferSchmittetal., author = {Herrmann, David and Schaeffer, Leon and Schmitt, Lukas and K{\"o}rber, Wolfgang and Merker, Lukas and Zentner, Lena and B{\"o}hm, Valter}, title = {Design, Erprobung und Vergleich von zwei Manipulatoren auf Basis von nachgiebigen Tensegrity-Strukturen}, series = {10. IFToMM D-A-CH Konferenz 2024: 05./06. M{\"a}rz 2024, Universit{\"a}t Rostock}, journal = {10. IFToMM D-A-CH Konferenz 2024: 05./06. M{\"a}rz 2024, Universit{\"a}t Rostock}, doi = {10.17185/duepublico/81587}, abstract = {Kurzfassung des Tagungsbeitrags.}, language = {de} } @article{BeckerBoehmSchaleetal., author = {Becker, Tatiana I. and B{\"o}hm, Valter and Schale, Florian and Zimmermann, Klaus}, title = {Vibrating sensor unit made of a magnetoactive elastomer with field-adjustable characteristics}, series = {Journal of Magnetism and Magnetic Materials}, volume = {498}, journal = {Journal of Magnetism and Magnetic Materials}, number = {March}, publisher = {Elsevier}, doi = {10.1016/j.jmmm.2019.166196}, abstract = {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.}, language = {en} } @misc{ChavezVegaBoehmScharffetal., author = {Chavez Vega, Jhohan Harvey and B{\"o}hm, Valter and Scharff, Moritz and Prem, Nina and Monkman, Gareth J. and Becker, Tatiana I. and G{\"u}nther, L. and Alencastre, Jorge H. and Grieseler, R. and Zimmermann, Klaus}, title = {Magneto-active elastomer as viscoelastic foundation material for artificial tactile sensors with tuneable properties}, series = {Book of Abstracts of the 16th German Ferrofluid Workshop, Braunschweig, 18.-20.07.2018}, journal = {Book of Abstracts of the 16th German Ferrofluid Workshop, Braunschweig, 18.-20.07.2018}, pages = {16 -- 17}, language = {en} } @article{SchaefferHerrmannSchratzenstalleretal., author = {Schaeffer, Leon and Herrmann, David and Schratzenstaller, Thomas and Dendorfer, Sebastian and B{\"o}hm, Valter}, title = {Theoretical considerations on stiffness characteristics of a 3-dimensional tensegrity joint model for the use in dynamic hand orthoses}, series = {Journal of Medical Robotics Research}, journal = {Journal of Medical Robotics Research}, publisher = {World Scientific}, doi = {10.1142/S2424905X25400069}, language = {en} } @inproceedings{HerrmannKunzeKobesetal., author = {Herrmann, David and Kunze, Julian and Kobes, Julian and Seelecke, Stefan and Motzki, Paul and Rizzello, Gianluca and B{\"o}hm, Valter}, title = {A mobile tensegrity robot driven by rolled dielectric elastomer actuators}, series = {2025 IEEE 8th International Conference on Soft Robotics (RoboSoft), 22-26.April 2025, Lausanne}, booktitle = {2025 IEEE 8th International Conference on Soft Robotics (RoboSoft), 22-26.April 2025, Lausanne}, publisher = {IEEE}, doi = {10.1109/RoboSoft63089.2025.11020974}, pages = {6}, abstract = {This paper presents a tensegrity-based mobile robot powered by dielectric elastomer actuators (DEAs), which provide high compliance and adaptability. The design consists of two V-shaped members linked by DEAs, enabling both symmetrical and asymmetrical actuation for varied movement patterns. Modal analysis and simulations show that uniform DEA actuation supports efficient linear motion, while asymmetrical actuation enables controlled circular paths. Experimental testing highlights the influence of voltage waveforms, frequencies, and surface types on speed, with optimal performance achieved using rectangular waveforms on low-friction surfaces. The robot reaches a top speed of 188 mm/s, among the highest reported for DEA-driven robots.}, language = {en} } @inproceedings{SchaefferSchmausserHerrmannetal., author = {Schaeffer, Leon and Schmaußer, Theresa and Herrmann, David and Lehmann, Lukas and Dendorfer, Sebastian and B{\"o}hm, Valter}, title = {Multi-Body Simulation of a Dynamic Hand Orthosis based on a Prestressed Compliant Structure Incorporating the Human Hand}, series = {2025 International Symposium on Medical Robotics (ISMR), May 14-16, 2025, Atlanta, GA, USA,}, booktitle = {2025 International Symposium on Medical Robotics (ISMR), May 14-16, 2025, Atlanta, GA, USA,}, publisher = {IEEE}, doi = {10.1109/ISMR67322.2025.11025982}, pages = {80 -- 86}, abstract = {Many dynamic hand orthoses use one degree of freedom joints, such as hinge joints. Therefore, these orthoses can only partially replicate the complex, multi-axis movement of the hand. A possible solution for this is the use of prestressed compliant structures as the basis for orthoses. Determining the joint forces in the wrist and optimizing the dynamic orthosis to influence these forces as well as acting muscle forces are important steps in the development of these orthoses. For this reason, in this work multi-body simulation models of an orthosis with human hand models are presented. Based on these theoretical investigations, more detailed orthosis models as well as initial prototypes of prestressed compliant dynamic hand orthoses can be developed.}, language = {en} } @misc{MerkerBoehmZentner, author = {Merker, Lukas and B{\"o}hm, Valter and Zentner, Lena}, title = {A tensegrity-based elastic joint element}, series = {IFToMM WC 2023 - The 16th World Congress of the International Federation for the Promotion of Mechanism and Machine Science, 5-10 November, Tokyo, Japan}, journal = {IFToMM WC 2023 - The 16th World Congress of the International Federation for the Promotion of Mechanism and Machine Science, 5-10 November, Tokyo, Japan}, language = {en} } @inproceedings{LehmannHerrmannSchaefferetal., author = {Lehmann, Lukas and Herrmann, David and Schaeffer, Leon and Albaik, Mohammed and M{\"u}ller, Emily and Rizzello, Gianluca and B{\"o}hm, Valter}, title = {Biomimetic Auxetic Compliant Tensegrity Metamaterial with Tunable Poisson's Ratio for the Application as a Soft Robotic Skin}, series = {2025 IEEE International Conference on Cyborg and Bionic Systems (CBS), Beijing, China ;10/17/2025 - 10/19/2025}, booktitle = {2025 IEEE International Conference on Cyborg and Bionic Systems (CBS), Beijing, China ;10/17/2025 - 10/19/2025}, publisher = {IEEE}, isbn = {979-8-3315-9742-9}, doi = {10.1109/CBS65871.2025.11267590}, pages = {188 -- 193}, abstract = {The use of compliant tensegrity grids offers significant potential for adaptive and lightweight systems for applications in soft robotics. This paper presents foundational investigations into a new class of auxetic tensegrity metamaterials. This work demonstrates that the auxetic behavior of a tensegrity grid can be realized and tuned solely through the mechanical properties of tensioned members, without altering the equilibrium geometry, offering a key advantage over conventional auxetic structures with fixed topologies. To validate the concept, 3D-printed demonstrators are manufactured, tested and a possible application as a cylindrically shaped soft robotic skin is shown.}, language = {en} } @inproceedings{SchaefferLiebrechtSchmausseretal., author = {Schaeffer, Leon and Liebrecht, Melanie and Schmaußer, Theresa and Herrmann, David and Lehmann, Lukas and B{\"o}hm, Valter}, title = {Finite element analysis of a tensegrity joint model for the use in dynamic hand orthoses}, series = {2025 9th International Conference on Biomedical Engineering and Applications (ICBEA), Seoul, Republic of Korea, February 27 - March 2, 2025}, booktitle = {2025 9th International Conference on Biomedical Engineering and Applications (ICBEA), Seoul, Republic of Korea, February 27 - March 2, 2025}, publisher = {IEEE}, isbn = {979-8-3315-3571-1}, doi = {10.1109/ICBEA66055.2025.00016}, pages = {41 -- 48}, abstract = {Many current dynamic hand orthoses use single degree of freedom joints, such as hinge joints. Consequently, these orthoses can only partially replicate the complex, multi-axis range of motion of the hand. To overcome this limitation, one approach is to use prestressed compliant structures as the basis for orthoses. In order to be able to map the dynamic influences on the orthosis as well as to simulate everyday use, this article provides an overview of this orthosis concept and the most important aspects in the development of such an orthosis including the results of the modal analysis. Based on these theoretical investigations, the presented methodological approach can be used to develop initial prototypes of tensegrity-based hand orthoses.}, language = {en} }