Micro Sensors for Real-time Monitoring of Mold Spores and Pollen

Organic airborne particles such as mold spores and pollen cause a variety of diseases. Two types of micro sensors for real-time monitoring of such organic airborne particles have been developed using semiconductor thin-film. A basic type thin-film sensor has a simple configuration with a double-layered sensing film deposited on an alumina substrate. A MEMS type sensor is composed of two parts: a sensing element and a micro heater. Both parts are fabricated by using thin film technology, IC fabrication process and micromachining technique. The double-layered sensing film is deposited on a diaphragm formed on a Si substrate. A thin film heater is placed in parallel at a distance of about 50 im. The resistance of both sensors steeply decreases and then recovers to the initial value when a mold spore or a grain of pollen adheres to the surface of the sensing film and burns on it. The resistance change and the recovery time depend on the size of the organic airborne particles. Thus it is p (More)