A smart actuator-based underwater microrobot with two motion attitudes

Various microrobots were widely used in the fields of biomedical engineering and underwater operation during the last few years. By having a compact structure, low driving voltage and a simple control system, microrobots could complete a variety of underwater tasks, even in limited spaces. To realize the multifunctionality of the microrobot for adapting to complex underwater environments, we proposed a walking biomimetic microrobot with two kinds of motion attitudes, lying state and standing state. The microrobot used eleven ICPF (ionic conducting polymer film) actuators to move and two SMA (shape memory alloy) actuators to change motion attitude. In the lying state, the microrobot could implement stick insect-inspired walking/rotating motion, fish-like swimming motion, horizontal grasping motion, and floating motion. In the standing state, it could implement inchworm-inspired crawling motion along two directions and vertical grasping motion. Then we developed a prototype of multi-functional biomimetic microrobot and evaluated its walking, rotating and floating speeds experimentally. Experimental results indicated that the robot could obtain a maximal walking speed of 3.6mm/s, a maximal rotating speed of 9deg/s and a maximal floating speed of 7.14mm/s.