On-Chip Self-Sensing Piezoelectric Micro-Lens Actuator With Feedback Control

High-speed micro-lens actuators are required for fast auto-focusing in miniaturized cameras. The speed can be enhanced by adding damping at the resonance frequency through feedback control. Previous approaches to implement control were based on expensive OFF-chip bulky laser sensors that not suitable In this article, using an ON-chip self-sensing piezoelectric sensor with a novel readout circuit, passive resonant controller (PRC) is designed, implemented, and tested. stability of closed-loop actuator guaranteed use mixed negative-imaginary (NI) passivity theory design. performance circuit compared sensor, results show comparable performance. damps fundamental mode 20.6 dB, which similar 21.9 dB reduction obtained sensor. settling time less than 10 ms, also 8 ms signal-to-noise ratios (SNRs) 108 118 respectively. These replace without sacrificing performance, making it more appealing portable micro-optics devices.