Development of an electrical current stimulator for activating muscle tissues in biohybrid machines

Soft and flexible robots are being developed as an alternative to traditional robotics. While they offer significant adaptability to the external environment, the integration of biological tissues as actuators presents several challenges. One of the critical challenges is the activation of the biological tissues to contract and move the robotic system's joints. In this paper, we discuss the development of an electrical current stimulator that can activate muscle tissues in soft robotic systems. The stimulator, realized with commercial components and designed using a stacked approach, combines a power supply board and an electrical stimulation front-end. A stacked-design approach allows to keep the device compact, with a total size of 59 mm x 28 mm x 25 mm (lxwxh). The stimulator, which has a power consumption of 1.3 W, can deliver up to 18 mA of stimulation current, and it has been verified to activate muscle tissues, demonstrating the ability to trigger muscle contraction by inducing up to 178 µN of contraction force.