FABRICATION OF MICROMACHINED SILICON TIP TRANSDUCER FOR TACTILE SENSING

The tunneling vacuum diode was employed to construct a novel displacement transducer for tactile sensing. High sensitivity of the emission current to variations of cathode-anode separation is the most important feat re. The device was fabricated on a silicon wafer. The device components are a single tip or an array of tips made by wet etching, and a metal anode diaphragm. Nitric acid-ammonium fluoride etchant is used at room temperature to etch the silicon tips, with an easily controlled etch rate and excellent uniformity. A unique sacrificial layer technique creates and controls the spacing between cathode tip and anode diaphragm. Highly sensitive responses of the device current to different force loads on the anode diaphragm are presented.