Soft tensegrity structures with variable stiffness and shape changing ability
The project goal is to investigate intrinsically compliant tensegrity structures on the basis of highly elastic materials with pronounced stiffness change and shape change
abilities with respect to applications in soft material robotic systems. The consideration of smart soft materials with energyless (passively) adaptable dynamical behavior in
these structures builds an important part of the investigations.
The guiding hypothesis in the context of investigations is: Intrinsically compliant tensegrity structures differ significantly from other compliant structures, due to their prestress and specific morphology. Based on these two main characteristics, these structures are promising for further realization of advanced soft material robotic systems with highly adaptable mechanical behavior. By using smart materials in these structures and members with simultaneous sensing and actuating capabilities, a high level of functional integration of these systems can be achieved.
Therefore, the exploration and analysis of these structures with intrinsic compliance and the achievement of fundamental principles of their soft behavior will be considered within the project, by using a holistic approach consisting of structural, material and manufacturing aspects.
Due to the lack of systematic research on intrinsically compliant elastomer tensegrity structures, and to explore their promising characteristic properties, the goals of the investigations in the first application period lie on (A) method development, belonging to theoretical description of the properties and mechanical behavior of these structures by providing suitable design-tools at different levels of abstraction (form-finding, stiffness characterization, shape and stiffness change characterization by actuation), (B) considerations corresponding to the advantageous use of smart soft materials in these structures, (C) experimental verification of theoretical results and demonstration of structural properties and performance of these structures with demonstrators, (D) and based on these studies, the development of design guidelines for these structures, used as actuators, variable stiffness structures and structures with passive adaptable compliance as well as finally (E) the classification of these specific structures.
Possible applications of these structures are variable stiffness structures with actively and passively changeable mechanical compliance, actuator systems, and fully or partially compliant structures with predefined adaptable directional variability of stiffnesses. In the first application period, basic researches on the suitability of compliant tensegrity structures for these applications will be carried out. The results of the fundamental research within this project build the basis to exploring potentials, advantages and limitations by using these structures in soft material robotic systems.