A silicon-based micro-flow sensor with Sandwich structure was designed according to the mechanism of opto-pneumatic detection and fabricated by micro-electro-mechanical system (MEMS) technology. A snaky platinum film resistor of 1.6 kΩ with the temperature coefficient of resistance of 2. 2 × 10 -3/ ℃ was fabricated as the heater and the thermometer. The platinum film was supported by beams of 4 μn silicon nitride and the power consumption is 44 mW at the operating temperature of 125 ℃. The effects of the space between two platinum resistors and the working temperature on the properties of the micro-flow sensor were investigated and the sensor was applied for CO2 gas detection. The developed micro-flow senor exhibits linear relationship between signal and gas flow with the flow range from 0 to 1 mL/min and the detection limit is about 8.5 μ/min, which are suitable for opto-pneumatic detection for infrared gas absorption.%针对气体红外吸收的气动探测应用,设计了基于MEMS技术的Sandwich结构硅基微流量传感器.在1 mm2面积内制备了阻值约1.6 kΩ的蛇形Pt薄膜作为加热及测温电阻,其电阻-温度系数(TCR)约2.2×10-3/℃.Pt薄膜采用4 μm厚氮化硅悬梁作支撑,在125℃工作温度下功耗约44 mW.研究了Pt薄膜电阻对的间距以及工作温度对微流量传感器性能的影响,并将其用于CO2气体检测.在0～1 mL/min的测试范围内,该微流量传感器输出信号与气体流量成线性关系,理论检测下限约8.5 μL/min,可用于气体红外吸收的气动探测.
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