A Large-Stroke 3-DOF Micromirror With Novel Lorentz Force-Based Actuators Utilizing Metallic Glass Thin Film

Abstract

An electromagnetic tip-tilt-piston micromirror with a large stroke is presented. This research introduced a novel actuation structure, based on a spring made from conductive metallic glass with excellent mechanical properties. For the first time, two functional elements, an electromagnetic actuation element and a mechanical support structure, were successfully integrated into a single-layer spring, made of metallic glass. With this novel actuator, the performance of stroke and angle controllability is remarkably improved. The fabricated device can achieve a $418 ~\mu \text{m}$ static stroke in upward direction. Furthermore, the tilting angles of the micromirror can be controlled with maximum accuracy of 0.05°/mA. The device is robust and has miniature dimensions, comparable or smaller, than existing electromagnetic micromirror dimensions published in literature. The displacement values of the micromirror are larger, compared to state-of-the–art electromagnetic micromirrors, which usually have strokes under $300 ~\mu \text{m}$ and do not have angle control mechanism. In spectrometer applications, the micromirror with a large stroke and controllable angle allows spectrometers to achieve higher resolution. These special qualities of the micromirror, will provide efficient, and reliable spatial light modulation required for interferometer applications. [2023-0104]