An Integrated CMOS Mems Gas Flow Sensor with Detection Limit Towards Micrometer Per Second

We report an integrated Thermoresistive Micro Calorimetric Flow (TMCF) sensor with the detection limit towards μm/s level by using proprietary InvenSense CMOS MEMS technology. The TMCF sensor shows a prominent normalized sensitivity of 533μV/(m/s)/mW for N2 flow (-1.29m/s~1.29m/s). With the very low flow testing in the mixed convection regime , the TMCF sensor shows a good resolution of less than 3.2mm/s and Minimum Detectable Flow Velocity (MDFV) of less than 1.6mm/s (2% error). Moreover, the intrinsic MDFV and resolution of the TMCF sensor to the noise level at the zero flow is determined as good as 30μm/s and 60μm/s, respectively. Therefore, this proposed TMCF sensor will be a promising flow device for ultra-low fluid flow measurements in micro/nanofluidics.