An 8x8 Robust Capacitive Pressure Sensor Array

Abstract

Abstract In this work, robust substrates, such as stainless steel, have been studied as substrates for micromachined devices. The use of robust substrates may allow for the co-fabrication of micromachined devices and sensor packages. Lamination process techniques combined with traditional micromachining processes have been investigated as suitable fabrication technologies. To illustrate these principles, a capacitive pressure sensor array has been designed, fabricated, and characterized using a stainless steel substrate, Kapton polyimide film as a suspended movable plate, and an electroplated nickel fixed back electrode. The net capacitance change of this sensor over the applied pressure range (0 to 34 kPa) was approximately 0.14 pF. Multivibrator circuitry has been integrated with pressure sensors in a hybrid fashion and used for frequency-modulated output measurements. An important attribute of this design is that only the steel substrate and the pressure sensor inlet is exposed to the flow; i.e., the sensor is self-packaged.