Development of Multi-Joint Biohybrid Soft Robot by Using Skeletal Muscle Tissue

Abstract

Various forms of biohybrid robots have been developed; however, creating robots with multiple degrees of freedom remains a challenging task. In this paper, we developed a multi-joint biohybrid robot by using skeletal muscle tissue. To achieve this, we first developed a modular bio-actuator actuated by skeletal muscle tissues. The objective of this study was to enhance the contraction force of the actuator and establish optimal experimental conditions for creating high-performance robots. By applying continuous electrical stimulation for five days during culture of bio-actuator, we were able to increase the contraction force by more than threefold. Additionally, we determined the appropriate electric field based on the electrode distance, which enabled us to establish an optimal experimental setup. We also confirmed that connecting the actuators in series can significantly increase the moving distance. Connecting two actuators in series resulted in a total movement distance equivalent to the sum of the distances of each actuator. This finding suggests the potential to create robots with a larger operational workspace. Using these actuators, we first constructed a manipulator with a rotational joint. This research is expected to contribute not only to the development of various robots utilizing bio-actuators but also to advancements in biology technology.