University of Washington Engineers Unveil 1-Gram Hopping Robot With Precise Height Control

Engineers at the University of Washington have developed a miniature hopping robot weighing approximately 1 gram (0.04 ounces) that can precisely control its jump height to clear obstacles such as standard stair steps. The system, dubbed DirectHop, offers a low-power alternative to aerial drones by leveraging a form of locomotion that is nearly two orders of magnitude more energy-efficient than sustained flight.

The underlying research, first reported by TechXplore (https://techxplore.com/news/2026-09-tiny-robot-precisely-height.html), will be presented on Sept. 30 at the International Conference on Intelligent Robots and Systems (IROS 2026). Senior author Sawyer Fuller, an associate professor of mechanical engineering at the University of Washington, led the project alongside lead author Hanquan (John) Wang, a graduate research assistant at the university.

Conventional miniature hopping machines often imitate insect physiology by using latches and mechanical springs. While spring-loaded designs can propel small devices over substantial distances, discharging a spring is an all-or-nothing action that prevents fine adjustment of jumping distances. Springs and latch mechanisms are also complex to manufacture and operate at ultra-small scales.

DirectHop bypasses springs entirely, utilizing a tiny electric motor connected to a central tower by a length of fishing line. Rapid motor acceleration spools the line to hoist the mechanism while three hinged legs maintain structural alignment. By adjusting the electrical current delivered to the motor, the researchers demonstrated the ability to dictate jump height with an accuracy of 1 centimeter (0.4 inches).

To manage landing instability, the palm-sized prototype features a protective roll cage inspired by the shell structure of box turtles. When the machine lands on its side, lowering the motor back down the central tower shifts its center of gravity, rolling the unit back onto its base. The team achieved a 90% success rate in self-righting tests.

While the current prototype relies on tethered power cables and lacks steering mechanisms, the development team is actively working on solutions for autonomy. Planned upgrades include onboard batteries, solar cells, a vibration motor for rotational positioning, micro retractable feet to adjust launch angles, and integrated cameras paired with onboard processors to enable autonomous stair-climbing capabilities.

The researchers anticipate that component simplicity will keep hardware manufacturing costs low. Wang estimated that production costs could drop to roughly $10 per unit, enabling the deployment of swarms containing hundreds or thousands of robots. Such fleets could carry out industrial leak detection in refineries, monitor agricultural resources, or perform planetary exploration at a fraction of the cost of larger robotic platforms.