A miniaturized wall-climbing segment robot inspired by caterpillar locomotion

Caterpillars are very successful soft-bodied climbers that navigate in complex environments. This paper develops a multi-segmented robot climbing on vertical surfaces using dry adhesive pads, inspired by caterpillar locomotion. The miniaturized robot consists of four segments, and each segment uses a solenoid actuator with a permanent magnet plunger. The head and body segments adapt a novel mechanism and Scott-Russell linkages to generate a bi-directional plane motion using one solenoid actuator, resulting to reliable attaching and peeling motions of gecko pads. A tail is also attached at the back of the last segment to avoid falling or exhibiting unstable motion. Gecko-inspired adhesive pads are fabricated from polydimethylsiloxane (PDMS) with the area of 20 mm  ×  10 mm. We have conducted experiments on the locomotion performance of the segment robot climbing vertical surfaces for two types of locomotion, achieving the fast and stable climbing motion.