A Bioinspired Tensegrity Actuator Inspired by Sarcomeres

Abstract

Flexible actuators are core components of soft robots that aim to mimic the compliant and adaptive motion of biological muscles. However, traditional flexible actuators often face common challenges, such as low stiffness, slow response times, and a lack of intrinsic stability and self-recovery capability. Inspired by the “rigid–flexible coupling” structure of biological sarcomeres, this study presents a bioinspired tensegrity actuator (BTA) based on a tensegrity structure. By integrating a tensegrity skeleton and using a casting process to fabricate pneumatic bellows as the driving units, the BTA combines the stabilization mechanism of the tensegrity structure with the biomimetic motion of flexible actuators, thereby addressing the insufficient stiffness and stability issues associated with traditional actuators. Furthermore, a kinematic model is developed and combined with the Monte Carlo method to analyze the workspace. Subsequently, contraction tests, bending tests, step response experiments, comprehensive mechanical property tests, and load capacity tests were performed to verify the good motion and mechanical performance of the BTA. In addition, two-finger, three-finger, and serial assemblies composed of multiple BTA units successfully completed grasping tasks with bananas, tomatoes, and eggs, demonstrating the good motion flexibility and practical application potential of the BTA.