Microchannel pressure sensor

Abstract

The invention discloses a microchannel pressure sensor which comprises the components of a tested fluid bypass microchannel (1), a micro-capacitance signal measuring system (2) and liquid micro-electrode channels (3). The liquid micro-electrode channels (3) are symmetrically configured at two sides of a micro-channel detecting segment (4) of the tested fluid bypass microchannel (1). Each liquid micro-electrode channel (3) is provided with a liquid micro-electrode inlet (5) and a liquid micro-electrode outlet (6). The two liquid micro-electrode channels (3) are connected with the micro-capacitance signal measuring system (2). According to the microchannel pressure sensor, micro-electrodes are formed at two sides of the micro-channel detecting segment (4). A pressure change in the tested fluid bypass microchannel (1) is obtained through measuring the capacitance, thereby improving measuring accuracy, reducing an interference to liquid flow and furthermore realizing simple manufacture and low cost.

Description

technical field [0001] The invention relates to the technical field of micro-channel pressure detection, and more particularly to a micro-channel pressure sensor. Background technique [0002] Microcapacitive pressure sensor is an important component for detecting microfluidic pressure in microfluidic system, and it is a device for pressure detection in micron-scale or even smaller-scale flow channels. The fluid pressure detection in the flow channel is generally divided into contact type and non-contact type. The main difference between the two is whether the measuring element is in contact with the fluid to be measured. The contact pressure measurement method is to install a pressure sensor at the measured point, and the pressure-sensing element directly contacts the measured medium, converts the pressure value into an electrical signal and transmits the signal in a way that is suitable for the site, which can be directly and simply felt. The pressure changes, but its dis...

AI Technical Summary

Problems solved by technology

The contact pressure measurement method is to install a pressure sensor at the measured point, and the pressure-sensing element is directly in contact with the measured medium, converts the pressure value into an electrical signal and transmits the signal in a manner suitable for the site, which can be directly and simply felt The pressure changes, but its disadvantages are also obvious: on the one hand, due to the contact between the measuring element and the fluid, the sensor will affect the flow of the fluid, especially for the flow channel at the micro-nano scale. On the other hand, the contact sensor The flow channel will be modified, which will increase the difficulty of the manufacturing process and increase the production cost; the non-contact pressure sensor has a displacement sensor and a capacitive sensor. The amount of deformation can be used to calculate the internal fluid pressure of the pipeline; the non-contact type also has an ultrasonic pressure detection sensor. It propagates in a straight line at a constant speed, and when it propagates from one medium to another, it will produce the principle of reflection and refraction, and then use the probe to receive these reflected and refracted ultrasonic waves to the ultrasonic instrument, which will be enlarged and displayed on the ultrasonic display screen by the ultrasonic instrument , the disadvantage is that the signal at the micro-nano scale is too small, easily disturbed, and the accuracy is too poor

[0003] In short, the existing technology has poor accuracy in detecting the pressure of the microchannel and has technical defects that affect the flow of liquid in the microchannel.

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