@inproceedings{HerrmannSchaefferLehmannetal., author = {Herrmann, David and Schaeffer, Leon and Lehmann, Lukas and B{\"o}hm, Valter and Rieffel, John}, title = {Basic Investigations on a Compliant 2D Tensegrity Grid for the Use in Soft Robotic Applications}, series = {2024 6th International Conference on Reconfigurable Mechanisms and Robots (ReMAR), 23-26 June 2024, Chicago, IL, USA}, booktitle = {2024 6th International Conference on Reconfigurable Mechanisms and Robots (ReMAR), 23-26 June 2024, Chicago, IL, USA}, publisher = {IEEE}, isbn = {979-8-3503-9596-9}, doi = {10.1109/ReMAR61031.2024.10619926}, pages = {652 -- 657}, abstract = {The use of compliant tensegrity grids in soft robotic applications is a promising research topic. By using these grids, systems with large shape and stiffness change ability can be realized. In this paper, different tensegrity grid variants, consisting of rigid members indirectly connected via compliant tensioned members, are presented. A selected grid variant is analyzed in more detail for shape adaptation. Therefore the use of the grid as end effector in form-fit grippers is selected as a specific application case. Covariance Matrix Adaptation Evolution Strategies are used to optimize actuators for two given shape function variants and an evaluation is carried out.}, language = {en} } @misc{HerrmannSchaefferBoehm, author = {Herrmann, David and Schaeffer, Leon and B{\"o}hm, Valter}, title = {Theoretical considerations on 2D multistable tensegrity structures based on equilateral triangles}, 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 = {403 -- 404}, language = {en} } @inproceedings{SchaefferHerrmannBoehm, author = {Schaeffer, Leon and Herrmann, David and B{\"o}hm, Valter}, title = {Voruntersuchung einer vorgespannten nachgiebigen Struktur f{\"u}r den Einsatz in dynamischen Handorthesen}, 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/77392}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:465-20230314-153711-8}, abstract = {In diesem Beitrag erfolgt die theoretische Untersuchung einer zweidimensionalen nachgiebigen Tensegrity-Struktur in Hinsicht auf ihre potenzielle Eignung als Basisstruktur f{\"u}r eine dynamische Handorthese. Translatorische und rotatorische relative Bewegungsm{\"o}glichkeiten zwischen den Drucksegmenten der Struktur sind m{\"o}glich, da diese Segmente durch nachgiebige Zugsegmente miteinander verbunden sind. Die Form der Struktur und ihre Vorspannung in einer statisch stabilen Gleichgewichtskonfiguration werden mit Hilfe der Minimierung des Kr{\"a}fte- und Momentenungleichgewichts, der Betrachtung der potentiellen Energie der Struktur und einem Ansatz mittels statischer Finite-Elemente-Methode (FEM) in Abh{\"a}ngigkeit der Segmentparameter untersucht.}, language = {de} } @article{SchaefferHerrmannSchratzenstalleretal., author = {Schaeffer, Leon and Herrmann, David and Schratzenstaller, Thomas and Dendorfer, Sebastian and B{\"o}hm, Valter}, title = {Preliminary theoretical considerations on the stiffness characteristics of a tensegrity joint for the use in dynamic orthoses}, series = {Journal of Medical Robotics Research}, journal = {Journal of Medical Robotics Research}, publisher = {World Scientific}, doi = {10.1142/S2424905X23400081}, abstract = {Early motion therapy plays an important role for effective long-term healing of joint injuries. In many cases, conventional dynamic orthoses fail to address the intricate movement possibilities of the underlying joints, limited by their simplistic joint representations, often represented by revolute joints, enabling rotations by only one axis. In this paper, a two-dimensional compliant tensegrity joint for use in biomedical applications is investigated. It consists of two compressed members and five compliant tensioned members. Relative movement possibilities are realized by the intrinsic compliance of the structure. In the development of these systems, the first step is the determination of the static stable equilibrium. This analysis is conducted in this paper by considering the potential energy approach or by using the geometric nonlinear finite element method. The mechanical behavior of the structure is assessed with a specific emphasis on its mechanical compliance. The primary objective of this study is the investigation of the influence of structural parameters on the overall stiffness and movability of the structure. The results underscore the significant effect of member parameters on the stiffness and movability of the compliant tensegrity joint, particularly under varying load magnitudes. These findings provide insights for optimizing the joint's performance, contributing to its potential application in advanced orthotic and exoskeleton devices.}, language = {en} } @inproceedings{SchaefferHerrmannBoehm, author = {Schaeffer, Leon and Herrmann, David and B{\"o}hm, Valter}, title = {Concept of a wrist Hand Orthosis based on a prestressed compliant structure}, series = {Proceedings of the 7th International Conference on Biomedical Engineering and Applications (ICBEA), Hangzhou, China, 21-23 April 2023}, booktitle = {Proceedings of the 7th International Conference on Biomedical Engineering and Applications (ICBEA), Hangzhou, China, 21-23 April 2023}, publisher = {IEEE}, doi = {10.1109/ICBEA58866.2023.00024}, pages = {98 -- 103}, abstract = {In the treatment of hand injuries in the context of orthopedic care, movable wrist hand orthoses are used in numerous instances. Early motion therapy is in most cases advantageous for adequate, rapid and successful long-term healing of the hand. Conventional dynamic wrist 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 hand movement possibilities. In this paper, a preliminary concept for dynamic wrist hand orthoses based on prestressed compliant structures is presented. The distinctive feature of this concept lies in the enabling of multiaxial motion capabilities of the human hand without applying conventional joints. According to the concept the wrist region is surrounded by a prestressed compliant structure. Besides the derivation and description of the concept, a first three-dimensional computer-aided design is shown. Additionally, the necessary steps in the development of such a novel dynamic wrist orthosis are discussed.}, language = {en} } @inproceedings{HerrmannSchaefferLehmannetal., author = {Herrmann, David and Schaeffer, Leon and Lehmann, Lukas and Busch, Tobias and B{\"o}hm, Valter}, title = {Preliminary Theoretical Considerations on 2D Multistable Tensegrity Structures Based on Equilateral Triangles}, series = {New trends in mechanism and machine science: Proceedings of EuCoMeS 2024}, booktitle = {New trends in mechanism and machine science: Proceedings of EuCoMeS 2024}, editor = {Rosati, Giulio and Gasparetto, Alessandro and Ceccarelli, Marco}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-67294-1}, doi = {10.1007/978-3-031-67295-8_21}, pages = {183 -- 191}, 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{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} }