A CAVITY-LESS MICROMACHINED CAPACITIVE PRESSURE SENSOR FOR WIRELESS OPERATION IN LIQUID AMBIENT

摘要: This paper reports a micromachined capacitive pressure sensor that does not use the traditional cavity and diaphragm, its in aqueous environment. The device is fabricated with two plates of stainless steel an intermediate polymer layer soft enough to deform target range. A polyurethane room-temperature-vulcanizing liquid rubber 38-μm thickness used as deformable material. For frequency-based interrogation capacitance, passive inductor-capacitor tank by combining inductive coil, which formed using 80-μm-diameter copper wire. Wireless sensing demonstrated monitoring variation resonant frequency via external coil magnetically coupled tank. sensitivity at room temperature measured be 23-33 ppm/KPa over dynamic range 340 KPa, shown match theoretical estimate obtained bonded elastomer model. geometrical impact on response also evaluated.