An insect-scale quadruped robot with a mechanically coupled transmission for confined environments

Abstract Insect-scale robots hold promise for exploration and rescue in confined environments, yet achieving simultaneous fast locomotion, high payload capacity, and long endurance under severe mass and volume constraints remains a fundamental challenge. Here, we present a 20.9 g, 6 cm insect-scale quadruped robot enabled by a mechanically coupled single-degree-of-freedom transmission. By tuning the transmission ratio, we engineered two distinct configurations. The high-torque variant utilizes a three-stage gearbox to transport up to 250 g—12 times its own weight—and sustains a 12 N quasi-static load, while the standard configuration achieves a forward speed of 36.9 cm/s. Operating untethered with wireless control, the robot completes more than 400 m of continuous locomotion. Furthermore, it successfully executes teleoperated pickup-and-return tasks within physically confined spaces. These results establish a mechanically coordinated design strategy that links high agility, load-bearing capacity and task-level integration at insect scale.