Biosyncretic robots have potential advantages associated with both living organisms and electromechanical systems. Skeletal muscle tissue is a candidate as bioactuators for biosyncretic robots because of its excellent contraction force and controllability. However, the low quality of myoblast (C2C12) differentiation into contractile myotubes and the lack of control research on biosyncretic robots are two of the main challenges in the development of biosyncretic robots. In this study, an approach with circularly distributed multiple electrodes (CEs) is proposed to improve C2C12 differentiation and to control the movement of a myotube-based biosyncretic crawling robot. To analyze the advantages of the proposed CEs, the electrical characteristics of CEs and a pair of traditional parallel stimulation electrodes (PEs) were simulated and compared with each other. Then, to determine the optimal electrical stimulation parameters and demonstrate the superiorities of the proposed CEs, electrical pulses with different parameters were used to stimulate two-dimensional and three-dimensional cells during culture with the proposed CEs and PEs. After this the control characteristics of the muscle tissue by the CEs were investigated from the relevance of pulse width-threshold voltage, voltage-contractility, frequency-contractility, and electric field direction-contractility by measuring the real-time responses of myotubes to different electrical stimulations. Moreover, to demonstrate the control of biosyncretic robots by the CEs, a biomimetic biosyncretic crawler actuated by myotubes was designed, fabricated, and controlled to move at different speeds by varying directions of electric field. This study not only provides a potential tool for the development and control of biosyncretic robots but is also informative for muscle tissue engineering and cardiomyocyte culture.
Keywords: C2C12; biohybrid devices; biosyncretic robots; differentiation; living machines; soft robots.