A sensor platform based on piezoresistive cantilever

In this paper U-shaped as well as rectangular piezoresistive cantilever array have been designed and fabricated based on silicon micromachining technology. Single crystalline silicon is used as the piezoresistive material. The sensitivities and the noises of piezoresistive cantilevers were systematically investigated from both the theory and the experimental results. The minimum detectable deflections (MDD) of piezoresistive cantilever are calculated to be 0.3 nm for rectangular cantilever and 0.2 nm for U-shaped cantilever at a 6 V bias voltage and a 1000 Hz measurement bandwidth. Using polymer-coated cantilevers as a chemical sensor, its response to water vapor was tested by measuring its output voltage signals. The measurement shows that the sensor sensitivity is high and the response is quick.