A digital-to-analog converter of displacement by an integrated micromechanism

We have newly invented a micromechanism for precise position control, which is equivalent to that of an electrical digital-to-analog converter(DAC) of the R-2R resistor network. The micromechanical C-2C compliance suspension network has been fabricated on a silicon-on-insulator wafer by a micromachining technique. When N-bit digital driving voltages are applied to the micromechanism, cascaded electrostatic microactuators produce a set of displacements of +/-1 mu m. These displacements accumulate in the suspension network with binary weights to synthesize DAC-like displacement output. A traveling displacement of 6 mu m is obtained while the positioning resolution is 0.38 mu m in the case of 4 bit input. Resolution can be improved further by increasing the addressing size of the input.