A microchannel pressure sensor

Abstract

The invention discloses a micro-channel pressure sensor, which comprises a micro-channel (1), a micro-capacitance signal measurement system (2), and a liquid micro-electrode channel (3); The liquid microelectrode channel (3) is symmetrically arranged on both sides of the microchannel detection section (4) of the channel (1), and the liquid microelectrode channel (3) has a liquid microelectrode inlet (5) and a liquid microelectrode outlet (6). The two liquid microelectrode flow channels (3) are both connected to the micro capacitance signal measurement system (2). The present invention forms micro-electrodes on both sides of the micro-channel detection section (4), and obtains the pressure change in the side branch micro-channel (1) of the measured fluid by measuring the capacitance, which improves the measurement accuracy and reduces the interference to the liquid flow , while making simple, low-cost.

Description

technical field [0001] The invention relates to the technical field of microchannel pressure detection, and more specifically relates to a microchannel pressure sensor. Background technique [0002] Microcapacitive pressure sensor is an important component for detecting microfluidic pressure in microfluidic systems, and it is a device for detecting pressure in micron-scale or even smaller-scale flow channels. 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 measured fluid. 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 di...

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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