Novelmicro Transportation Systems Based on Ratchetmechanism and Electrostatic Actuators

This paper describes a design and fabrication of Si micro transportation systems (MTS) to drive microcars based on ratchet mechanism and electrostatic comb-drive actuators. This MTS consists of linear and rotational comb actuators, microcars, and micro ratchet mechanism. The microcars can be moved with different velocities by comb-drive actuators through ratchet teeth. In this study, the MTS was fabricated by using SOI wafer with device layer of 30μm, buried SiO
₂
layer of 4μm, and with only one mask. In our experiments, the movement of the microcar has been tested with driving frequency ranges from 5Hz to 40Hz. The velocity of the microcar was proportional to the driving frequency, and it matched well with theoretical calculation.