ChevBot – An Untethered Microrobot Powered by Laser for Microfactory Applications

Abstract

In this paper, we introduce a new class of submillimeter robot (ChevBot) for microfactory applications in dry environments, powered by a 532 nm laser beam. ChevBot is an untethered microrobot propelled by a thermal Micro Electro Mechanical (MEMS) actuator upon exposure to the laser light. Novel models for opto-thermal-mechanical energy conversion are proposed to describe the microrobot's locomotion mechanism. First, an opto-thermal simulation model is presented which is experimentally validated with static displacement measurements with microrobots tethered to the substrate. Then, stick and slip motion of the microrobot was predicted using a dynamic extension of our simulation model, and experiments were conducted to validate this model in one dimension. Promising microrobot designs were fabricated on a silicon on insulator (SOI) wafer with 20 μm device layer and a dimple was assembled at the bottom to initiate directional locomotion on a silicon substrate. Validation experiments demonstrate that exposure to laser power below 2W and repetition frequencies below 60 kHz can generate actuator displacements of a few microns, and 46 μm/s locomotion velocity.