A micromachined nanopositioner with on-chip electrothermal actuation and sensing

This letter describes the design of a micromachined nanopositioner with thermal actuation and sensing capabilities in a single chip. The positioner has a dynamic range of 14.4 μm, and the sensor drift is 8.9 nm over 2000 s with a differential sensing scheme. The on-chip displacement sensing enables a feedback control capability. A proportional–integral feedback controller is designed and implemented digitally. The closed-loop step response results show a positioning resolution of 7.9 nm and a time constant of 1.6 ms.