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 by 44.5% and lowers angular creep rates by 36.2%. Under 50°C accelerated aging, lifetime increases from 248 hours to over 688 hours, projecting to ~ 7,650 hours at room temperature—meeting automotive light detection and ranging (LiDAR) demands. Key innovations include: (1) parameter distribution optimization to minimize the maximum stress 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.