Low power sub-milligram resonant MEMS load sensor

A miniaturized resonant load sensor demonstrating sub-milligram sensitivity is presented. The sensor response is not limited by creep and hysteresis often observed in traditional load sensors. A prototype sensor demonstrates a resolution of 0.1 mg over a load range of 300 mg demonstrating excellent linearity over this range (R2=0.9998). An energy efficient front-end CMOS readout circuit consumes only 5 μW from a 1.2 V supply