Piezoresistive geometry for maximizing microcantilever array sensitivity

Abstract

Our group has focused on the development of piezoresistive cantilevers for gas detection using a nonreactionbased method -viscous damping. This work represents a continuation of this effort by reporting on the development, fabrication and testing of a second generation device consisting of asymmetric piezoresistive cantilevers to maximize device sensitivity. The first mode of resonance, static & dynamic sensitivities, and Q-factors ranged from 40 kHz -63 kHz, 1-6 Ω/µm & 3-17 Ω/µm, and 1700 -4200, respectively, depending on piezoresistor geometry and beam length. The redesigned piezoresistive microcantilevers were 15 -200 times more sensitive than the best symmetric design previously reported by our group.

Improved fabrication and modeling of piezoresistive microcantilever beams for gas detection and sensing.

“…Research at UofL has utilized an asymmetric base arrangement in the sensor design; this has greatly improved device sensitivity. [15][16] Other researchers have pursued size reductions towards the nanoscale to increase sensitivity of beam sensors. [17][18] [20] In addition to the challenges of inducing vibration, microscale devices are quite sensitive to a host of effects, such as the viscosity of any surrounding gas, that could often be neglected when dealing with traditional macro structures.…”