LTOI 单压电晶片中的高速鞭状模式微谐振器：测量方法与大幅信号表征
High-Velocity Whip-Mode Microresonator in LTOI Unimorph: Measurement Methodology and Large-Signal Characterization
- The University of Texas at Austin（德克萨斯大学奥斯汀分校）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文提出LTOI单压电晶片锥形悬臂梁鞭状模式微谐振器，通过几何放大实现高速测量，在192 Vpp下提取尖端速度达58.9 m/s，为MEMS惯性传感器提供可行路径。
AI中文摘要：
本文介绍了基于绝缘体上钽酸锂（LTOI）单压电晶片平台的高阶鞭状模式弯曲微谐振器的设计、表征及大幅信号测量方法。锥形悬臂梁通过结构速度放大效应将动能集中于自由端，目标鞭状模式频率为9.175 MHz，在空气中测得品质因数Q为691。结果表明，在高模态频率下，该器件对粘性阻尼的敏感性显著降低。在另一器件上进行的空气中大幅信号测试证实，在锥形尖端处激光多普勒测振仪（LDV）的可靠测量范围被超过之前，尖端速度可达20 m/s，而器件本身在失效前可承受高达240 Vpp的驱动电平。过渡到真空环境后，LDV激光照射下LTOI悬臂梁出现光热引起的静态弯曲，该效应阻碍了对这些谐振器进行直接速度测量。因此，这促使采用间接提取方法。本工作中，一个在低驱动下独立校准的3.85倍基底至尖端几何放大因子被应用于基底速度测量，以推断大幅信号条件下的尖端速度。使用该方法配合窄带啁啾激励，在192 Vpp下获得最大提取尖端速度为58.9 m/s，对基底速度的频谱分析为该估计值设定了36.2 m/s的保守下限。大幅信号失效模式分析确定，Pt/Au电极在210 Vpp时熔化是当前速度上限的原因。这些结果表明，高阶弯曲模式中的几何放大为下一代MEMS惯性传感器所追求的高检测质量速度提供了一条可行途径。
英文摘要：
This paper presents the design, characterization, and large-signal measurement methodology of a high-order whip-mode flexural microresonator on a lithium tantalate-on-insulator (LTOI) unimorph platform. A tapered cantilever concentrates kinetic energy at the free tip through a structural velocity amplification effect, with a targeted whip mode at 9.175 MHz exhibiting a measured Q of 691 in air. The results indicate a substantially reduced susceptibility to viscous damping at high modal frequencies. In-air large-signal testing on a separate device confirms tip velocities up to 20 m/s before the reliable measurement range of the laser Doppler vibrometer (LDV) at the tapered tip is exceeded, while the device itself sustains drive levels up to 240 Vpp before failure. Transitioning to vacuum reveals photothermal-induced static bending of the LTOI cantilever under LDV laser illumination, an effect that prohibits direct velocity measurement for these resonators. Hence, it motivates an indirect extraction methodology to be implemented. In this work, a 3.85 times base-to-tip geometric amplification factor, independently calibrated at low drive, is applied to base velocity measurements to infer tip velocity under large-signal conditions. Using this approach with narrowband chirp excitation, a maximum extracted tip velocity of 58.9 m/s is obtained at 192 Vpp, with spectral analysis of the base velocity placing a conservative lower bound of 36.2 m/s on this estimate. Large-signal failure-mode analysis identifies Pt/Au electrode melting at 210 Vpp as the current velocity ceiling. These results suggest that geometric amplification in high-order flexural modes offers a viable pathway toward the high proof-mass velocities targeted for next-generation MEMS inertial sensors.
