Development of a complete dual-axis micromachined convective accelerometer with high sensitivity

A convective accelerometer is an accelerometer, which contains neither a solid proof mass nor moving components. It mainly consists of heaters and thermal sensors which measure temperature differences caused by free convection due to an input acceleration. In this paper, we report a complete dual-axis micromachined convective accelerometer with high sensitivity and an effective microfabrication process to realize the device. Compared with other convective accelerometers, our design shows dramatically increased sensitivity with a low operating power as well as improved linearity and response time by integrating a unique heater design and controlling key design parameters. In order to examine the performance of our device, various parameters, such as heating power, packaging volume and its gas medium, are considered and tested. According to our current design, a sensitivity of 2.8 mV/g is obtained with an operating power of 10 mW using SF₆ as an enclosed gas medium.