講演情報
[23p-12E-6]Air Damping Effect on Quality-Factor in High-Order Resonance Modes of Single-Crystal Diamond Microcantilevers
〇(DC)Guo Chen1,2, Zilong Zhang1, Keyun Gu1, Liwen Sang1, Satoshi Koizumi1, Yasuo Koide1, Zhaohui Huang2, Meiyong Liao1 (1.National Institute for Materials Science, 2.China University of Geosciences (Beijing))
キーワード：
single-crystal diamond、MEMS cantilever、energy dissipation
Single-crystal diamond (SCD) for micro/nanoelectromechanical systems (MEMS/NEMS) has attracted a lot of interest because of their numerous outstanding properties, such as the highest Young’s modulus, the highest thermal conductivity, and low intrinsic dissipation. Resonant cantilevers with high-frequency and high-quality (Q) factors hold great promise for high-sensitivity and high-resolution sensors. Under practical use, resonators are always operated in atmospheric air, and this environment significantly impacts their Q-factor in comparison to vacuum conditions. For MEMS cantilevers, air damping is very pronounced, particularly in the fundamental resonance mode. However, the resonant behavior in high-order modes of SCD cantilevers against pressures has not been reported yet. In this work, we fabricated diamond cantilevers and investigated the effect of gas atmosphere on Q-factor in high-order resonance of SCD MEMS cantilevers. The Q-factor of the high-order modes is found to be nearly constant up to pressures between 10-4 to 100 Pa and then decreases to less than 1,000 in 103 Pa, similar to the fundamental mode. Compared to the high-order modes, the first mode has higher Q-factors in vacuum (intrinsic regime). Nevertheless, the high-order modes in the molecular and viscous flow regimes (P > 101 Pa) exhibit higher Q-factors than the fundamental mode. Hence, in low-vacuum and atmospheric environments, the high-order resonance modes provide a profound sensitivity improvement for MEMS sensing devices, attributed to the much higher f·Q product.