DirectHop: A one-gram robot that jumps with centimeter accuracy

A robot the size of a finger that hops on its own. On 23 September 2026, researchers at the University of Washington presented a jumper weighing about one gram. It performs several jumps in sequence and clears an ordinary stair step to within a centimeter. t3n and the university both reported on the system, called DirectHop.

How the jump works

A tiny electric motor and three folding legs drive the robot. The researchers say the jump height can be controlled to within one centimeter. This precision turns a series of jumps into a steerable path rather than random hops. The prototype fits in a palm. When the robot falls over, a short, fast movement of the motor sets it upright again. In the tests, this worked in 90 percent of cases.

Sawyer Fuller, associate professor of mechanical engineering at the University of Washington and lead author of the work, identifies three core problems: varying the jump distance, righting the robot, and recharging energy for the next jump. DirectHop solves all three with a completely new design, Fuller said. On-board power, control, and navigation are the next tasks, he adds. Small walking robots are difficult precisely because these elements must work together. A device that jumps well once is not a functional robot.

Why jump instead of fly

The researchers estimate that hopping is about two orders of magnitude more energy-efficient than flying. This is critical for small powered robots, where the power supply is the hardest constraint. Every gram of battery adds weight to the mechanics. A biological comparison illustrates the principle. A flea jumps about 50 times its own body height without continuous energy expenditure. A mosquito, by contrast, hovers only as long as it applies force.

Classical mechanical engineering has solved the problem differently so far. Many jumpers are spring-loaded and released by latches. Springs and latches are difficult to build and control at very small scales. Releasing a spring is an all-or-nothing process, making it hard to dose the jump distance. DirectHop therefore eliminates the spring entirely. It uses a very small electric motor that accelerates fast enough to trigger the jump directly. According to the university, the results were presented on 30 September at the International Conference on Intelligent Robots and Systems (IROS).

Possible fields of use

The tasks named are those where large machines are too expensive or too heavy: finding gas leaks in a refinery, monitoring water and fertilizer levels on farmland, or exploring unknown terrain. Extremely light, energy-saving robots are also discussed for exploring other celestial bodies.

For German robotics, the approach is interesting above all for its method. Progress today comes less from larger motors than from the combination of precise control, mechanical simplicity, and an energy calculation over the whole path. In practice, such systems can only be deployed if they survive operation without constant manual intervention.

Jumping costs about two orders of magnitude less energy than flying, and at a total weight of one gram, that is decisive.