Biomimetic-Inspired Silicon-Honeycomb/PDMS Hybrid Damper for Piezoelectric MEMS Microspeakers

This study proposes a piezoelectric MEMS microspeaker featuring a novel biomimetic-inspired silicon-honeycomb/PDMS hybrid passive damper that synergistically combines geometric compliance and viscoelastic material damping. The integration of PDMS through a custom-developed EBLO process ensures high pattern fidelity and excellent reproducibility. As a result, the proposed design achieves up to 49.5 % and 75.4 % reductions in the$Q$-factor compared with multi-cantilever type and Y -spring type reference devices, respectively. Under a driving condition of 20 Vpp, it delivers a sound pressure level (SPL) of 105 dB at 1 kHz, with resonance peak suppression of 8 dB and 12 dB relative to the references, and reduces maximum total harmonic distortion (THD) from 26 % and 61 % to 13 % (51 % and 22 % of those of the reference structures). These results demonstrate a new approach to achieve high-fidelity MEMS audio performance through a structural-material hybrid damping design.