A High-Speed Capacitive Humidity Sensor

U. Kang, K.D. Wise
1998 1998 Solid-State, Actuators, and Microsystems Workshop Technical Digest   unpublished
This paper reports a high-speed capacitive humidity sensor with an integrated boron-diffused heater. A response time of 1.0sec and a sensitivity of 30.0fF/%RH have been obtained with the fabricated devices. High speed is achieved using multiple polyimide columns having diameters of a few microns and allowing moisture to diffuse into them circumfer entially, altering the dielectric constant. A subsecond response time is expected when the geometry is further reduced. The purpose of the heater is
more » ... o enable the sensor to recover from contamination and aging. It allows bake-out of the sensing film on demand and is useful in self-test protocols.
doi:10.31438/trf.hh1998.40 fatcat:f2ma4luqsrfhxeolvpgx4enrea