Piezoresistive sensing in a strongly-coupled high Q Lamé mode silicon MEMS resonator-pair

We present a 13 MHz strongly coupled bulk Lamé mode silicon MEMS resonator-pair with quality factor (Q) of 10⁶ (i.e. f·Q product of 1.3×10¹³) in addition to a 28 dB increase in transduction by uniquely adapting the coupling spring as an integrated piezoresistor. Our device exploits and preserves the intrinsic high Q of the isochoric Lamé mode while also tapping into the high concentration of stress in the coupling spring as the pair of Lamé mode resonators is synchronized to resonate in phase. This concentration of stress along the coupling beam benefits the output transduction efficiency, which in turn results in enhancing overall transduction while preserving very high Q. Q of the device also remains stable with increasing bias current.