Soft robots capable of leaping upward or forward when exposed to infrared light have been developed by a team of researchers from North Carolina State University.
According to the robots’ developers, the so-called 'ring leaper' design uses torsion to store elastic energy and then releases that energy all at once, which means the robots do not need to reset between jumps, but repeat themselves instead.
Source: Fangjie Qi
This is possible because the robots are composed of a liquid crystal elastomer tear-shaped ribbon that features a thin V-shaped aluminum tube at one end. This ribbon's surface contracts when exposed to light from an infrared lamp, which causes the ribbon to rotate.
Meanwhile, the rigid V-shaped structure prevents the ribbon from rolling in place, which enables it to store energy. When the twist reaches a critical point, the stored energy is released, causing the V to snap downward and launch the robot into the air. The robot subsequently returns to its original shape, repeating the jumping motion while it is exposed to infrared light.
Minor modification to the robots’ geometry controls how the robots move. For instance, a 120-degree V makes the robots crawl, 90 degrees makes them jump forward and 50 degrees makes them vertically leap. Adding a small weight to the robots’ rounded ends also increases jumping distance by shifting the robots’ center of mass for more powerful, stable movements.
The infrared light also influenced the robots’ jumping behavior. In other words, it has to be strong enough to encourage jumping, but not so strong that the robots jump erratically and unpredictably.
When trialed, these robots jumped across slopes, hurdles and assorted other surfaces like grass, sand, rocks and mulch.
The team suggests that while there currently aren’t specific use cases for such robots, there one day may be for fields like environmental navigation, swarm robotics and unstructured terrain navigation.
An article detailing the robots, “A self-resetting soft ring for autonomous, continuous leaping in unstructured environments,” appears in the journal Proceedings of the National Academy of Sciences.
For more on the robots, watch the accompanying video that appears courtesy of North Carolina State University.
