Gait Exploration of Sub-2 g Robots Using Magnetic Actuation

This work describes a method to study terrestrial robot locomotion at small scales (robot mass < 2 g) and is inspired by incredible feats of locomotion by natural organisms like insects at these same scales. 3-D printing was used to fabricate lightweight robots and magnets were embedded in the robot legs. An external magnetic field was then applied to actuate the legs and move the robot. To illustrate the studies that this method enables, a number of different quadrapedal gaits (e.g., pronking, trotting, bounding, and waddling) are demonstrated by changing the orientation of the magnets in the robots' legs, and the robot is tested at a variety of speeds (up to 3.9 body lengths per second) and over multiple terrains, with random height variations up to 8.3 mm (1.47 times hip height). These results demonstrate the versatility of magnetic actuation to study terrestrial locomotion at small scales; a single control signal can produce a variety of gait patterns.