Static Hysteresis Mitigation for PZT MEMS Varifocal Liquid Lens

Piezoelectric MEMS varifocal lenses suffer from static hysteresis, which degrades optical precision. This work presents a novel approach to mitigate hysteresis using integrated piezoresistive sensors. The sensors provide real-time displacement monitoring, allowing for improved actuator linearity <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(R^{2}=0.99)$</tex> compared to conventional open-loop control methods. A fabricated MEMS actuator with a PZT thin film and embedded sensors demonstrates significant reduction in focal length deviation. Experimental results confirm the feasibility of sensor-based compensation, paving the way for more precise tunable optics in applications requiring compact autofocus systems. Future work will focus on closed-loop implementation for enhanced optical performance and stability.