A novel micro transportation system with fast movement of a micro container based on electrostatic actuation and a ratchet mechanism

Abstract

This paper presents a novel micro transportation system (MTS), which can drive micro containers in both straight and curved paths based on an electrostatic comb actuator and a ratchet mechanism. The micro container, which has four driving wings and four anti-reverse wings attached to its central ‘backbone’, is driven to move forward only by an electrostatic actuator. While the driving wings act as the legs of a water strider to push the container forward, the anti-reverse wings work as a ratchet mechanism to prevent the container from moving backward. The container with a length, width and thickness of 500 µm, 250 µm and 30 µm, respectively, moves unidirectionally with a desirable velocity up to 1000 µm s−1 in straight and curved paths. The velocity can be changed by varying the frequency and/or amplitude of the driving voltage. The MTS has been fabricated from SOI (silicon on insulator) wafer utilizing silicon micromachining technology with only one mask.