Image Courtesy: NC State University
Researchers have developed a soft robot that can repeatedly jump without being manually reset, as long as it remains exposed to infrared light. A simple change to its design can also determine whether the robot crawls, jumps forward, or launches itself vertically.
The teardrop-shaped device was created by researchers at North Carolina State University. Its unusual movement is powered by a self-resetting mechanism that stores elastic energy through twisting before releasing it in a sudden burst. The robot then automatically returns to its original position and begins the process again.
The robot consists of a ribbon made from liquid crystal elastomer, a material that changes shape when exposed to infrared light. A thin, V-shaped aluminum component is attached to one end of the teardrop. As the light causes the elastomer to contract, the structure begins to rotate and twist.
Instead of simply rolling, the V-shaped component causes the robot to build up torsional energy. Once the twist reaches a critical point, that stored energy is suddenly released. The component snaps against the ground, launching the robot into the air before the entire structure resets itself.
“This ‘ring leaper’ design is very simple,” said Jie Yin, a professor of mechanical and aerospace engineering at NC State and the corresponding author of the research paper. “We use torsion to store elastic energy and then release that energy all at once.”
Researchers found that changing the angle of the V-shaped component dramatically altered the robot’s movement. At an angle of 120 degrees, the robot crawled forward. Reducing the angle to 90 degrees caused it to jump forward, while a 50-degree angle made it leap vertically.
The team also discovered that adding a small amount of weight to the rounded end could improve the robot’s jumping distance by changing its center of mass. Infrared light intensity also influenced its behavior, although excessive power caused the robot to move unpredictably.
In proof-of-concept tests, the robots crossed slopes and hurdles and moved across grass, sand, rocks, and mulch. The researchers say the technology has no immediate commercial application, but the self-resetting mechanism could eventually prove useful for environmental navigation, swarm robotics, and movement across difficult terrain.
