Piezoresistive Versus Piezoelectric Position Sensing in MEMS Micromirrors: A Noise and Temperature Drift Comparison

This letter presents a comparative study concerning the characterization of piezoresistive (PZR) and piezoelectric (PZT) tilt-angle sensing in MEMS micromirrors. Position tracking is mandatory in such devices, so to achieve high-resolution displays, and the control system must be accurate against noise sources and stable against drifts of physical parameters, such as ambient temperature. This letter presents the performance results achieved on PZR and PZT sensors integrated on the same micromirror, showing that, at the cost of a larger area occupation, the latter achieves ten times larger sensitivity (with improvements in the signal-to-noise ratio and thus in position accuracy), and a five times lower overall transduction variation under temperature changes.