Researchers built first soft robot
Researchers have built first soft robot that can move without mechanical parts. Representational image Reuters/Paul Hanna

Researchers have built a robot using soft, deployable materials. The first-of-its-kind robot can move without the help of motors or any other mechanical components. It walks when electric current is applied to the shape-memory alloy wires built into its frame.

Wei Wang and team at Seoul National University and Sungkyunkwan University, South Korea, say that the robot can be easily deployed and reconfigured into different forms, which makes it useful in space mission and seabed exploration.

Dubbed DeployBot, the robot is assembled from eight modules; four for the body and one for each of the four legs. The shape memory alloy wires in the robot's frame return to their original form when heated. According to the researchers, current causes the modules to contract or bend, allowing the robot to move.

The team has also demonstrated that the DeployBot can walk with two different gaits; the first, called an undulating gait, is similar to the way an inchworm creeps. It can also walk with an ambulating gait, which resembles the movement of a four-legged animal.

"The main advantage of this modular robot is robustness in various environments due to lack of mechanical systems such as motors and gears," coauthor Sung-Hoon Ahn at Seoul National University told

"Thus, problems facing motor-based robots, such as sealing and lubrication of mechanical systems in water or space environments, are not a problem for the smart actuator," Sung-Hoon said.

The robot can move at a speed of slightly more than two metres per hour. It can also turn, but at a slow rate with 21 strides to turn 90 degrees. Although it is not quite fast, it can still serve as a useful tool for applications that do not require speed.

The researchers expect the techniques used in the robot could also be used to make a wider variety of robot designs and functions.