Polarity-sensitive position controller for MEMS-based radiation sensing

To successfully deploy many advanced radiation detection schemes, strict control of the system's response to environmental influences is required. For micromechanical radiation detectors in particular, highly sensitive lever-motion sensors––with resolutions in the picometer range––require not only mechanical control, but overall thermal and electrical control in order to maintain a constant system response. In this work, we report on the successful development of a piezo-electric actuator controller that maintains sub-nanometer precision in a noisy environment. The inadequacy of proportional-integral-differential (PID) controllers is demonstrated and explained, and the implementation of a polarity-sensitive controller is detailed. The resulting temporal control scheme can be profitably deployed for other nonlinear systems requiring drift-free control.