Friction-driven Three-foot Robot Inspired by Snail Movement

Snails have amazing adhesive locomotion abilities which help them climb up walls and even across ceilings. They generate this versatile and stable movement by muscular exploiting travelling waves and friction modulation. Inspired by these characteristics, snail-like robots have recently become the focus of growing research. In this paper, we present a novel friction-driven three-foot snail-like robot which employs a simple mechanism to capture and replicate snail-like motion. This robot is driven by two servo motors, which makes it easy and low-cost to fabricate. The robot operates by breaking frictional symmetry in the cyclic motion of the three feet, in much the same way as the three-sphere Golestanian swimmer. The symmetry of its structure and properties of friction give the robot distinctive movements. We present a mathematical model of the robot's locomotion, focusing on its kinetic harmonic-peristaltic movement. We designed and fabricated the robot, then undertook simulations and experiments, which closely match the analytic solutions. This robot provides a new approach to realising simpler, lower cost, and potentially more efficient, biomimetic mobile robots.