Microcantilever-based Weather Station for Temperature, Humidity And Wind Velocity Measurement

The current study develops a new process for the fabrication of Pt resistor temperature detectors (RTD), cantilevers covered with a water-absorbent polyimide layer for humidity measurement and bending-up cantilevers to determining the wind velocity. Pt RTD's are fabricated on the silicon substrate. The temperature measurement is based on the linear resistance variations when temperature changes. The polyimide layer is spun on the cantilever to form a humidity sensing layer. A variation in humidity causes moisture-dependent bending of the microcantilever, which changes the measured resistance of the resistor on the microcantilever. The same type of microcantilever without spinning on polyimide is used to form an anemometer. It is found the cantilever slightly bends upward as a result of the released residual stress induced in the beam during the fabrication. When wind passes over the cantilever beam, a small deformation occurs. Variations in the wind velocity can therefore be determined by measuring the changes in resistance caused by the beam deflection using a LCR meter