Research on the output characteristics of MEMS convective accelerometer under heavy impact

Microelectromechanical system (MEMS) convective accelerometer based on convection heat transfer has many advantages such as simple structure, low cost and great anti-shock property. Due to its great anti-shock property, we research the output characteristics of the convective accelerometer with low measuring range (plusmn5 g) (g stands for acceleration of gravity) when the input is heavy impact (500~30,000 g). First, we introduce the structure and operating principle of the convective accelerometer and give the reason why it can endure heavy impact. Second, by the study of its structure and operating principle, we analyze theoretically the output characteristics of MEMS convective accelerometer under heavy impact. Grashof number, which governs the convection heat transfer process, is used to determine the output results. We draw the conclusion by qualitative analysis that the output is non-linear extremely to the input, even up to saturation. Then we take a series of impact test to a convective accelerometer. From the results of test, the theoretical analysis we have done is proved correct. Meanwhile, we find that when the amplitude and actuation duration of the impact reach certain value, the output of accelerometer hardly change. We summarize the output law of the convective accelerometer under heavy impact by analyzing the test results. According to its characteristics, we point out the potential application field of MEMS convective accelerometer such as steady threshold switch in the situation enduring heavy impact. The research provides a new idea to use MEMS convective accelerometer in heavy impact field and is a theoretical and testing base for its further research and application.