Scientists Create Caterpillar-like 'Soft Robot' That Can Crawl Under Obstacles

Researchers at North Carolina State University have created a caterpillar-like soft robot that can move forward, backwards, and crawl under objects. The caterpillar-bot’s movement is driven by a novel pattern of silver nanowires that use heat to control the way the robot bends allowing users to steer the robot in either direction and make it dip under obstacles. “A caterpillar’s movement is controlled by local curvature of its body – its body curves differently when it pulls itself forward than it does when it pushes itself backwards,” says Yong Zhu corresponding author of a paper and the Andrew A. Adams Distinguished Professor of Mechanical and Aerospace Engineering at NC State. Engineering soft robots that can move in two different directions is a significant challenge in soft robotics. The caterpillar-bot can achieve this as it consists of two layers of polymer, which respond differently when exposed to heat. The bottom layer shrinks, or contracts, when exposed to heat. The top layer expands when exposed to heat. The researchers can control which sections of the nanowire pattern heat up by applying an electric current, controlling the amount of heat. It is hoped that similar soft robot locomotion technology will eventually have various applications – such as search-and-rescue devices.