Scientists from North Carolina State University have created a soft robotic caterpillar that can move forwards and backwards through tight spaces. The robot’s movement is achieved through a mesh of silver nanowires that bend when heated. The team was inspired by the biomechanics of a caterpillar, which moves differently when it pulls forward than when it pushes backwards. This movement is a major challenge that is made possible by the embedded nanowire heaters.
The robot consists of two polymer layers that react differently to heat. The bottom layer contracts when it heats up, while the top layer expands. A mesh of fine silver nanowires is embedded in the polymer layers, with several connection points for electrical current. Individual sections can be heated to different degrees, depending on how much electricity is applied.
To move in any direction, the robotic caterpillar can pull itself forward or push itself backwards, moving faster or slower depending on the current applied. The correct cycle between tensing and relaxing the caterpillar muscle had to be found, however, to allow enough time for the body to relax before it contracts.
The researchers also crawled the robot under a small gap to demonstrate that it can be precisely controlled in height, upward tilt, forward and backward movement. This motion approach is energy efficient, and the team is striving for further advances by installing sensors to enable it to be used in search and rescue robots.
Overall, the development of soft robots marks a major advancement in robotics, as they are more flexible and adaptable to their surroundings than traditional rigid robots.
