Development of an Electrostatic Micro Transportation System (MTS) with Strider-like Movement of Micro Carts

This paper presents a novel micro transportation system (MTS), which can drive micro carts by utilizing electrostatic actuator and ratchet mechanism. The micro cart, which has driving-wings and anti-reverse-wings attached to its central ´backbone´, is driven by electrostatic actuator through the ratchet racks in the direction perpendiculars to the movement direction of the cart. The driving wings of the cart play a role like the legs of a water strider. The MTS was fabricated from SOI wafer by using only one mask. The movement of the micro cart has been tested with driving frequency ranges from 1 Hz to 20 Hz. The velocity of the micro cart was linearly proportional to the driving frequency, and it matched well with theoretical calculation. The MTS combined with microscopes is expected to be applied in bio-medical analysis for transportation and classification of small samples.