These Light-Powered Robots Can Keep Jumping Forever

A self-resetting soft robot can repeatedly jump under infrared light, with simple design changes controlling how and where it moves. A teardrop-shaped soft robot developed at North Carolina State University can keep jumping for as long as infrared light shines on it, without needing.

Depending on a simple change to its geometry, the same design can crawl forward, jump ahead, or leap vertically. The self-resetting movement comes from a mechanism that stores elastic energy through twisting and then releases it all at once.

What Happened

The work demonstrates a new approach to repeated jumping behavior in soft robotics. The robot consists of a liquid crystal elastomer ribbon formed into a teardrop, with a thin V-shaped aluminum tube attached at one end.

• This work was done with support from the National Science Foundation under grants 2329674, 2445551 and 2527304.

• Instead, they see the self-resetting mechanism as a foundation for exploring how soft robots might move through more complicated environments.

• The researchers are not proposing an immediate practical use for the design.

Key Details

Infrared light causes the surface of the ribbon to contract, which makes the ribbon rotate. Instead of allowing the ribbon to simply roll, the stiff V at one end forces it to twist progressively tighter.

• In proof-of-concept tests, the teardrop-shaped robots successfully leaped across slopes and hurdles and moved over surfaces that included grass, sand, rocks, and mulch.

• The light must be strong enough to trigger jumping, but excessive intensity can make the movement unstable.

• Infrared light intensity provides another level of control.

Why It Matters

Energy builds until the twist reaches a critical point. The stored energy is then released, snapping the V downward against the surface and launching the robot into the air.

• The researchers also found that adding a small amount of weight to the rounded end could improve jumping distance.

• In other words, a single geometric parameter determines whether it crawls, jumps forward, or leaps upward.

What Reports Say

Coverage of the story so far points to:

• Continued reporting by SciTechDaily as more details emerge