In this paper, a liquid-based micro thermal convective accelerometer (MTCA) is optimized by the Rayleigh number ( Ra ) based compact model and fabricated using the $0.35\mu $ m CMOS MEMS technology. To achieve water-proof performance, the conformal Parylene C coating was adopted as the isolation layer with the accelerated life-testing results of a 9-year-lifetime for liquid-based MTCA. Then, the device performance was characterized considering sensitivity, response time, and noise. Both the theoretical and experimental results demonstrated that fluid with a larger Ra number can provide better performance for the MTCA. More significantly, Ra based model showed its advantage to make a more accurate prediction than the simple linear model to select suitable fluid to enhance the sensitivity and balance the linear range of the device. Accordingly, an alcohol-based MTCA was achieved with a two-order-of magnitude increase in sensitivity (43.8 mV/g) and one-order-of-magnitude decrease in the limit of detection (LOD) ( $61.9~\mu \text{g}$ ) compared with the air-based MTCA. [2021-0092]

中文翻译：

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一种可靠的液体基 CMOS MEMS 微型热对流加速度计，具有增强的灵敏度和检测限

在本文中，一种基于液体的微热对流加速度计（MTCA）通过瑞利数（Rayleigh number）进行了优化（ Ra ) 基于紧凑模型并使用 $0.35\亩$ m CMOS MEMS 技术。为实现防水性能，采用保形Parylene C涂层作为隔离层，加速寿命测试结果为液基MTCA的寿命为9年。然后，考虑灵敏度、响应时间和噪声来表征设备性能。理论和实验结果均表明，流体具有较大的Ra 数可以为 MTCA 提供更好的性能。更重要的是，基于 Ra 的模型显示出比简单线性模型更准确预测的优势，可以选择合适的流体以提高灵敏度并平衡设备的线性范围。因此，实现了基于酒精的 MTCA，灵敏度提高了两个数量级 (43.8 mV/g)，检测限 (LOD) 降低了一个数量级（ $61.9~\mu \text{g}$ ) 与基于空气的 MTCA 相比。[2021-0092]