Rodriguez Janna, Chandorkar Saurabh A, Watson Christopher A, Glaze Grant M, Ahn C H, Ng Eldwin J, Yang Yushi, Kenny Thomas W
Department of Mechanical Engineering, Stanford University, Stanford, California, 95304, USA.
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California, 94025, USA.
Sci Rep. 2019 Feb 19;9(1):2244. doi: 10.1038/s41598-019-38847-6.
Silicon Microelectromechanical Systems (MEMS) resonators have broad commercial applications for timing and inertial sensing. However, the performance of MEMS resonators is constrained by dissipation mechanisms, some of which are easily detected and well-understood, but some of which have never been directly observed. In this work, we present measurements of the quality factor, Q, for a family of single crystal silicon Lamé-mode resonators as a function of temperature, from 80-300 K. By comparing these Q measurements on resonators with variations in design, dimensions, and anchors, we have been able to show that gas damping, thermoelastic dissipation, and anchor damping are not significant dissipation mechanisms for these resonators. The measured f · Q product for these devices approaches 2 × 10, which is consistent with the expected range for Akhiezer damping, and the dependence of Q on temperature and geometry is consistent with expectations for Akhiezer damping. These results thus provide the first clear, direct detection of Akhiezer dissipation in a MEMS resonator, which is widely considered to be the ultimate limit to Q in silicon MEMS devices.
硅微机电系统（MEMS）谐振器在计时和惯性传感方面有着广泛的商业应用。然而，MEMS谐振器的性能受到耗散机制的限制，其中一些耗散机制很容易被检测到且已被充分理解，但有些耗散机制从未被直接观测到。在这项工作中，我们展示了一系列单晶硅拉梅模式谐振器的品质因数Q随温度（80 - 300 K）变化的测量结果。通过比较这些在设计、尺寸和锚点存在变化的谐振器上的Q测量值，我们能够表明气体阻尼、热弹性耗散和锚点阻尼对于这些谐振器而言并非显著的耗散机制。这些器件测得的f·Q乘积接近2×10，这与阿基耶泽尔阻尼的预期范围相符，并且Q对温度和几何形状的依赖性也与阿基耶泽尔阻尼的预期一致。因此，这些结果首次清晰、直接地检测到了MEMS谐振器中的阿基耶泽尔耗散，而阿基耶泽尔耗散被广泛认为是硅MEMS器件中Q的最终极限。
