A High-Load Large-Stroke MEMS Micro-motion Platform Based on Polyimide/Al Bimorph for Optical Image Stabilization

This paper presents a novel micro-motion platform for optical image stabilization (OIS) and autofocus, featuring a platform that directly manipulates a CMOS image sensor (CIS). Based on the electrothermal actuation, the micro-motion platform has three-degree-of-freedom movement via parallel PSPI/Al lateral-shift-free (LSF) actuators around the platform. This design achieves simultaneous high-load capacity and large stroke - critical for moving image sensor chips - while maintaining low driving voltage. Its capacity to combine excellent loading performance with large displacement is demonstrated by its displacement of 240 μm when unloaded, 286 μm when supporting a CIS chip, and 320 μm when supporting an 80 mg load at 20 Vdc. Ultimately, through the imaging experiment of actively compensating for defocus blur by sensor displacement, the practical functions of this device's multi-axis image stabilization are verified. This work provides a key device design and integration process foundation for the development of the next generation of high-performance and miniaturized imaging systems.