@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} } @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} } @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{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{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{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} } @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} }