An optimized micromachined convective accelerometer with no proof mass

作者：Luo X B^*; Yang Y J; Zheng F; Li Z X; Guo Z Y

来源：Journal of Micromechanics and Microengineering, 2001, 11(5): 504-508.

DOI：10.1088/0960-1317/11/5/309

• Convective micromachined accelerometer
• Grashof number
• Low pressure chemical vapor deposition
• Microheater
• Proof mass
• Temperature sensors

Miniaturization, low cost and high performance of accelerometers have been the topic of extensive research. A kind of convective micromachined accelerometer without proof mass is described in this paper. It consists of a microheater and two temperature sensors which measure the temperature difference between two sides of the microheater caused by the effect of acceleration on free convection. The optimization consideration is conducted before fabrication; some key factors, heater size and power, cavity size, distance between the heater and the sensor and the working medium, are considered. The test for the optimized device shows that the linearity error is smaller than 0.35% under tilt conditions of natural gravity and smaller than 2% under acceleration to 10 g (g = 9.81 m s-2). A sensitivity of 600 μV g-1 is measured for operating power of 87 mW, the response frequency is about 75 Hz and the corresponding noise equivalent acceleration is approximately 1 mg Hz-1/2 at 25 Hz. The dependence of the sensitivity on the heating power is a nearly linear function and the resolution increases with heating power increasing.

• 出版日期2001
• 单位清华大学