Piezoresistive Geometry for Maximizing Microcantilever Array Sensitivity

Previous work showed the capability of T-shaped piezoresistive cantilevers to detect gas composition using a nonreaction-based method - viscous damping [1]. However, this geometry yielded only small changes in resistance. Computational studies [2] indicate that optimizing the geometry of the base piezoresistor increases device sensitivity up to 700 times. This work reports on the development and testing of these novel asymmetric piezoresistive cantilevers. The first mode of resonance ranged from 40 kHz to 63 kHz, depending on piezoresistor geometry and beam length. Initial testing on the redesigned piezoresistive microcantilevers indicates that the new designs are 15-200 times more sensitive than the best symmetric design previously reported by our group.