Elimination of Temperature Drift for MEMS Thermal Wind Sensor With On-Chip Surrounding Thermistor

A novel micro-electro-mechanical system (MEMS) thermal wind sensor based on silicon in glass (SIG) technology is proposed to eliminate temperature shift in this work. The on-chip surrounding ambient thermistor, thermally insulated from the heater, is connected to the central thermistor in the constant temperature difference (CTD) circuit. Consequently, temperature drift caused by variations in temperature coefficient of resistance (TCR) between ambient and chip sensing elements due to power supply fluctuations is mitigated. The finite element method (FEM) was employed to optimize the chip structure, ensuring that the silicon substrate remains at ambient temperature without sensitivity deterioration. Wind tunnel experiments demonstrate that the device operates within a range of 0 to 30 m/s, with power consumption varying from 72.3 mW to 116.7 mW. Compared to the sensor with off-chip ambient thermistor, the proposed device can reduce the speed error to $\pm ~0.15$ m/s with a decrease of 62%. Furthermore, temperature chamber experiments reveal that wind speed errors are reduced from $\pm ~0.45$ m/s to $\pm ~0.15$ m/s for the ambient temperature ranging from −10° to 50°C. The proposed MEMS thermal wind sensor, characterized by high precision and low drift, can offer wide-temperature-range application in future. [2025-0084]