Watch this little robot hop and swim like a frog

A new study published in Science Advances reveals a novel propulsion mechanism for small robots that can hop and swim, much like a frog. The research, co-led by Khalid Jawed of UCLA and Xiaonan (Sean) Huang of the University of Michigan, demonstrates that twisting and bending of elastic rods can produce a snapping motion that provides powerful, repeatable movements with minimal energy consumption.

The researchers found that the shape of the rod, rather than its size, determines whether it snaps sharply or deforms gradually, which could enable the development of tiny robots with powerful bursts of motion. The team built a robot prototype with snapping rods at the rear that can hop over various terrains, including sand, grass, and water with attached paddles.

The robot can navigate obstacle courses and even use light sensors to follow a light source, demonstrating potential applications for robots that must maneuver in cluttered environments or across both land and water. The project was funded by the National Science Foundation.