Optimizing fatigue resistance and lifetime of MEMS scanning mirrors with a novel coupled parameter distribution structural framework

We present a coupled parameter distribution structural optimization framework that enhances the fatigue resistance and extends the lifetime of micro-electro-mechanical systems (MEMS) scanning mirrors. Simultaneous refinement of the number, distribution, and local width of control points reduces maximum stress range amplitude (SRA) by 44.5% and lowers angular creep rates by 36.2%. Under 50 °C accelerated aging, lifetime increases from 266.0 h to over 690.7 h, projecting to 6658.3 h-9780.3 h at room temperature. Key innovations include: (1) parameter distribution optimization to minimize the maximum SRA in the torsion beam while preserving optical performance; (2) control point distribution strategies ensuring robust convergence; and (3) cubic spline interpolation for smooth, fabrication-ready geometries. This framework enables the determination of locally optimal structural configurations within the explored design space, providing a versatile route to extend MEMS scanning mirror lifetimes and manage fatigue in MEMS actuators.