Soft Robotics Without the Air

Soft robotics, using flexible grippers and other appendages, rather than the rigid devices that one sees most often, presents some exciting possibilities for adapting robots to different situations. One problem with most “soft robots” though is that they need a source of air to properly deform their appendages, thus they need a source of compressed air.

Engineers at the University of California San Diego, however, have been working on a way to construct these robots that rely on electricity only for both their movement and control. To accomplish this, they used liquid crystal elastomers, which change shape when heated. To make their tubular grippers, they sandwiched three heating wires in between two elastomer layers, then rolled them into a cylinder. With this arrangement, the tubes are able to bend in six different directions, with each of the three regions deforming differently depending on the applied current.

With these unique actuators, the researchers were able to make a three-jaw griper that can squeeze together to pick up objects. From there they constructed a four-legged robot that can move independently under control of a tiny Arduino Pro Mini. As of now, the actuators are quite slow, requiring 30 seconds for bends, and minutes to return to their original shape. The eventual goal is to make them bend as fast as human muscles, but for now the process looks really interesting when sped up by eight to 80X on video!