Liquid-based cmos mems micro thermal convective accelerometer

Abstract

This invention refers to a liquid-based micro thermal convective accelerometer (MTCA) optimized using a compact model based on the Rayleigh number (Ra). The MTCA is fabricated using CMOS MEMS technology. To ensure water resistance, an isolation layer such as a waterproof cover, exemplified by the conformal Parylene C coating, is employed. The device's performance is assessed in terms of sensitivity, response time, and noise. Theoretical and experimental findings establish that fluids with higher Ra numbers yield improved MTCA performance. 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. In some cases, the liquid of MTCA can be selected as alcohol, and an alcohol-based MTCA was achieved with a two-order-of magnitude increase in sensitivity and one-order-of-magnitude decrease in the limit of detection compared with the air-based MTCA.

Dependencies are inferred from the claim text.