A Fast Bipedal Biohybrid Crawler Driven by Single Muscle Swinging

Biohybrid robots actuated by living cells/tissues, a soft robot system that integrates many advantages of life systems and mechanical systems, are promising candidates for developing a new generation of biomedical and environmental monitoring robots. However, due to the limited muscle contraction performance and lack of flexible muscle contraction modes, biohybrid robots' low speed and flexibility have become a major challenge for their application. To overcome the limitation, different from the existing contraction mode along the longitudinal axis with pulse stimulation, we firstly adopted the square wave stimulation on triceps femoris tissue with pennate fibers arrangement from bullfrogs and found a novel muscle swinging mode with high flexibility and controllability. Based on it, we developed a biomimetic crawler actuated by triceps femoris tissue. The crawler achieved fast forward movement (average speed: ∼6.19 mm/s; maximum speed: ∼7.35 mm/s) and flexible turning ability (∼14.77°/s and ∼9.55°/s for left and right turning speed, respectively) in a liquid environment at room temperature. We believe that the results provide valuable references for the development of soft robots driven by muscle tissue and pave the way to fulfill lifelike motions and break through limitations in conventional biohybrid robots.