| In order to solve the shortcomings of the traditional differential pressure flow sensor which is difficult to measure the tiny flow,this paper proposes a differential pressure tiny flow measurement method based on graphene membrane,processes and fabricates the experimental sample of tiny flow sensor,and verifies the feasibility of the method through simulation and The feasibility of the method is verified by simulation and real flow experiments,and the main research contents are as follows:(1)The overall scheme of differential pressure micro flow sensor based on graphene membrane is given,and the conversion relationships between reflected optical power and F-P cavity length,F-P cavity length and deflection of graphene membrane,deflection of graphene membrane and pressure,differential pressure and flow of each physical quantity are studied,and the theoretical model of the measurement mechanism is established and verified by finite element simulation method.(2)According to the results of finite element simulation analysis,the dimensions of microfluidic chip and graphene membrane were optimized,based on which the graphene membrane pressure sensitive element and microfluidic chip were fabricated,and the experimental prototype of differential pressure micro flow sensor was fabricated.(3)The theoretical model of optical power and F-P cavity length was verified by F-P cavity length experiment,the theoretical model of F-P cavity length and graphene membrane pressure was verified by gas pressure experiment,and the characteristic relationship between optical power and pressure was obtained;the theoretical model of differential pressure and flow rate was verified by real flow experiment,and then the characteristic relationship between optical power and flow rate was obtained;the calibration experiment of the experimental sample tested the performance of the experimental The performance of the experimental sample was tested and the feasibility of the measurement method was verified. |
