In-Situ Semiconductor Position Sensor For Differentially Piezo-Driven Nanopositioners

We address design, implementation, and characterization of semiconductor strain gauges as stage displacement sensors with small footprint for piezo-driven nanopositioners in differential actuation mode. The results indicate that in this actuation mode, a differential sensing strategy provides much better accuracy than the conventional non-differential schemes. The proposed differential sensor has a large sensitivity of 4.4 V/mu m, 3 sigma-resolution of 2.4 nm, and bandwidth of 4 kHz.