Mechanical Quality Factor Evaluation of Damping Film Materials for Polymer/PZT Composite MEMS Actuator

This paper reports the experimental estimation of the mechanical quality factor ( $Q_{m}$ ) of polymer films, which can be used as damping materials for MEMS. Considering the application to MEMS devices, polymer/PZT composite actuators using two thick photoresists (TMMR-NA1000 and SU8) and PDMS were fabricated and the Q factors were evaluated in a vacuum environment. The comparison between the measured and simulated Q factor confirmed a $Q_{m}$ range of 14-18 for TMMR-NA1000, 13-20 for SU8, and 5-8 for PDMS, indicating the superior damping capability of PDMS. Additionally, it was also found that the PZT thin film used in this study exhibited $Q_{m}$ of 200-220 under the driving voltage of 2 Vpp with +1V DC offset. The evaluation approach developed for assessing $Q_{m}$ of polymer materials is straightforward, easily implementable, and has broad structure applicability, offering a promising tool for assessing a wide array of materials. [2024-0096]