Zhang Hemin, Pandit Milind, Sobreviela Guillermo, Parajuli Madan, Chen Dongyang, Sun Jiangkun, Zhao Chun, Seshia Ashwin A
The Nanoscience Centre, University of Cambridge, Cambridge, CB3 0FF UK.
Silicon Microgravity Ltd., Cambridge Innovation Park, Cambridge, CB25 9PB UK.
Microsyst Nanoeng. 2022 Feb 7;8:17. doi: 10.1038/s41378-021-00340-4. eCollection 2022.
Mode-localized sensors have attracted attention because of their high parametric sensitivity and first-order common-mode rejection to temperature drift. The high-fidelity detection of resonator amplitude is critical to determining the resolution of mode-localized sensors where the measured amplitude ratio in a system of coupled resonators represents the output metric. Operation at specific bifurcation points in a nonlinear regime can potentially improve the amplitude bias stability; however, the amplitude ratio scale factor to the input measurand in a nonlinear regime has not been fully investigated. This paper theoretically and experimentally elucidates the operation of mode-localized sensors with respect to stiffness perturbations (or an external acceleration field) in a nonlinear Duffing regime. The operation of a mode-localized accelerometer is optimized with the benefit of the insights gained from theoretical analysis with operation in the nonlinear regime close to the top critical bifurcation point. The phase portraits of the amplitudes of the two resonators under different drive forces are recorded to support the experimentally observed improvements for velocity random walk. Employing temperature control to suppress the phase and amplitude variations induced by the temperature drift, 1 noise at the operation frequency is significantly reduced. A prototype accelerometer device demonstrates a noise floor of 95 ng/√Hz and a bias instability of 75 ng, establishing a new benchmark for accelerometers employing vibration mode localization as a sensing paradigm. A mode-localized accelerometer is first employed to record microseismic noise in a university laboratory environment.
模式局域传感器因其高参数灵敏度和对温度漂移的一阶共模抑制能力而备受关注。对谐振器振幅的高保真检测对于确定模式局域传感器的分辨率至关重要，在耦合谐振器系统中，测量的振幅比代表输出指标。在非线性区域的特定分岔点处运行可能会提高振幅偏置稳定性；然而，非线性区域中振幅比比例因子与输入被测物之间的关系尚未得到充分研究。本文从理论和实验两方面阐明了在非线性杜芬区域中模式局域传感器对于刚度扰动（或外部加速度场）的运行情况。借助从理论分析中获得的见解，在接近顶部临界分岔点的非线性区域中运行，对模式局域加速度计的运行进行了优化。记录了不同驱动力下两个谐振器振幅的相图，以支持实验观察到的速度随机游走的改善情况。采用温度控制来抑制温度漂移引起的相位和振幅变化，运行频率处的噪声显著降低。一个加速度计原型设备展示了95 ng/√Hz的本底噪声和75 ng的偏置不稳定性，为采用振动模式局域作为传感范式的加速度计建立了新的基准。首次使用模式局域加速度计在大学实验室环境中记录微地震噪声。
