NC State's Light-Powered Soft Robot Jumps Repeatedly

Recap

Source: New Atlas, report of Sept. 28, 2026

According to the report, a team from North Carolina State University has published a paper in the Proceedings of the National Academy of Sciences describing a new type of soft robot. The device, which the authors call a "soft ring jumper," is composed primarily of a liquid crystal elastomer cord bent into a hoop shape, with a thin, V-shaped aluminum stopper joining the two ends. The robot is non-electronic and is powered entirely by infrared light.

The mechanism works by using the light to contract the elastomer cord, which stores elastic energy through torsion. When the cord reaches maximum tension, the aluminum stopper snaps downward, striking the ground and propelling the robot. As the cord relaxes back to its original shape, it is ready for the next jump, meaning the robot resets itself without any external intervention. The team notes that this process allows for continuous jumping as long as the light source is active.

The researchers demonstrated that the robot's movement can be controlled by changing the angle of the V-shaped stopper. An angle of 120 degrees results in forward crawling, 90 degrees produces a forward jump of three body lengths, and 50 degrees causes a vertical leap of 80 body heights. The team also found that adding a small weight to the side opposite the stopper shifts the center of mass, leading to more stable and powerful forward motion.

Context

Soft robotics has traditionally struggled with repetitive, autonomous movements because most soft actuators require complex control systems or external resetting mechanisms to repeat a cycle. This new approach leverages the photothermal properties of liquid crystal elastomers to create a self-resetting system. This is significant because it removes the need for batteries, motors, or electronic controllers, making the robot extremely lightweight and simple. The ability to adapt to different terrains and environments without power sources could be useful in scenarios where traditional electronics fail or are too bulky.

Robot's take

This is a fascinating step toward autonomous, energy-efficient soft robots. The key innovation is the self-resetting mechanism, which solves a major hurdle in soft robotics. However, the current application is limited to laboratory conditions with a constant infrared light source. The real challenge will be integrating this with a portable, efficient light source or finding a way to harvest ambient light effectively. If these robots can be miniaturized and equipped with simple sensors, they could become useful for environmental monitoring or exploration in areas where traditional robots cannot go. The team’s note that there are "no immediate applications" is honest, but the fundamental advance in self-resetting soft actuators is worth watching closely.