A mini robot weighing just 1 g, which moves through hopping and is powered by a tiny motor, has been developed by a team of engineers at the University of Washington (UW).
Aptly named DirectHop, the robot can fit in the palm of a human hand. According to its developers, DirectHop combines three folding legs with a miniature electric motor enabling it to leap higher than a standard stair, perform multiple consecutive hops and recover from a fall by righting itself.
Source: University of Washington
Since hopping uses far less energy than flying, the researchers see swarms of these robots as a cheaper alternative to drones for jobs such as inspecting oil refineries for gas leaks.
DirectHop generates its movement by rapidly reeling in a fishing line attached to a motor, with the other end suspended in a small wire cage. The inertia of the upward acceleration, and sudden stop of the motor, launches the entire device into the air. Three hinged legs fold outward as the motor climbs, keeping it aligned with the foot during launch. Unlike spring-powered robots, DirectHop can control its jump height by adjusting the electrical current to the motor.
Because DirectHop frequently lands on its side, the researchers added a protective roll cage designed to help the robot right itself after a jump. With the motor accounting for more than 80% of the robot’s weight, positioning it closer to the foot lowers DirectHop’s center of gravity, allowing the cage to tip the robot back onto its foot. In testing, the self-righting mechanism successfully recovered the robot in 90% of attempts.
The current version of DirectHop relies on a wired tether for power and control and cannot yet steer. To improve DirectHop’s mobility and autonomy, the team is developing onboard electronics and navigation cameras, along with solar cells and batteries to power the robot. Planned upgrades also include a vibration motor for rotating in place and tiny retractable feet for adjusting its hopping angle.
A paper detailing the technology behind DirectHop, “DirectHop: A Direct-Drive Insect-Sized Robot that can Control Jump Height and Self-Right,” will be presented at the International Conference on Intelligent Robots and Systems, held Sept. 27 to Oct. 1, 2026, in Pittsburgh, Pennsylvania.
