Single-drive 2-DOF wideband micromirror via mode interaction

Micromirror technology is one of the current research hotspots. In this work, what we believe to be a novel electrostatic 2-DOF micromirror structure with double-biased torsional axes is proposed. By introducing internal resonance, synchronous motions of the two axes with a locked frequency ratio under a single driving force were achieved within a wide frequency range. The mechanical structure can thus be greatly simplified, as well as the operating frequency band is broadened. Also, two driving methods were proposed to realize the density spot acquisition with a 1:2 frequency ratio. The macroscopic experiment is further carried out to verify the validity of the theoretical model, which successfully realized a 1:2 internal resonance. The structural optimization design of internal resonance micromirrors is discussed, and a band expansion of at least 135.58% can be achieved in the simulation results. Compared with the traditional resonant micromirrors, the proposed one greatly increases the operating band at a very small sacrifice of vibration amplitude, and the resonant state can be guaranteed in complex environments. This novel micromirror provides a new chip solution for portable devices in complex environments and greatly simplifies the structure of dual-axis resonant micromirrors, reduces processing costs, and improves processing reliability.