An Electromagnetically Driven Micromirror with a Large Stroke

In this research, a micromirror driven by electromagnetic force is designed and fabricated.The micromirror features a microfabricated L-shaped spring for large deflection and a bulk permanent magnet with a size of 1 × 1 × 1.5 mm 3 mounted on the micromirror for generating electromagnetic actuation force.The device has a footprint of approximately 10 × 10 mm 2 .The design of the micromirror is based on Castigliano's theorem, theoretic spring constant evaluation, and finite element analysis, which are applied to estimate the deflection.The fabricated micromirror can be actuated at the resonance frequency in the atmosphere.The piston vibration at a fundamental frequency of 26.6 Hz is desirable for Michelson interferometers.An 830 µm stroke is achieved by applying 1 Vpp at the resonance frequency, and a 4.44° tilting angle is observed.Overall, the large stroke of the fabricated micromirror implies that the electromagnetic micromirror is promising for high-resolution interferometer applications.