Micro Peristaltic Robot Simulating Earthworm and Its Control System

Based on the research of motion principle of earthworm, this paper proposed a micro bionic and peristaltic robot simulating the walking motion of earthworm. The robot consists of three flexible units: each unit is composed of two plates connected with three shape memory alloys (SMA) every 120 degrees, and rubber gas bag around the SMA wires inflated with air inside. The unit corresponds to a segment of an earthworm, and the SMA and rubber gas bag have the same functions as the cricoid and longitudinal muscles of earthworm, and the flexible unit can fulfill the same motion as the segment of earthworm. A control system was designed to fulfill control of the three flexible unit's motions, such as stretching, shrinking and bending. The experiments show that the micro robot can walk forward and backward, and choose the direction. This micro robot is of safety, flexibility and simple structure.