An Insect-Scale Self-Sufficient Rolling Microrobot

We design an insect-sized rolling microrobot driven by continuously rotating wheels. It measures 18 mm × 8 mm × 8 mm. There are 2 versions of the robot - a 96 mg laser-powered one and a 130 mg supercapacitor powered one. The robot can move at 27 mm/s (1.5 body lengths per second) with wheels rotating at 300$^\circ$/s, while consuming an average power of 2.5 mW. Neither version has any electrical wires coming out of it, with the supercapacitor powered robot also being self-sufficient and is able to roll freely for 8 seconds after a single charge. Low-voltage electromagnetic actuators (1V-3 V) along with a novel double-ratcheting mechanism enable the operation of this device. It is, to the best of our knowledge, the lightest and fastest self-sufficient rolling microrobot reported yet.

I. Introduction

The future is filled with milligram-scale microrobots (or, microbots) doing things like active remote sensing, searching for earthquake and other disaster survivors, and exploring other planets. These applications are mainly due to their small size, but this size also turns out to be challenging for their mobility in natural terrains. Robustness to tough terrains generally increases the less the bot interacts with the environment. Fliers minimize this interaction by flying over and avoiding the obstacles in contrast with earthworms (and ants) which have to crawl (and walk) over each little bump.