Device and method for measuring slip velocity at microscale

Abstract

A device for measuring slip velocity under micro-scale comprises a trace gas pump, a barometer, a microinjection pump, liquid, a rectangular channel, a high-speed camera system and a water tank which are connected through relations, the left side wall of the rectangular channel is a hydrophilic silicon wafer I, the right side of the rectangular channel is formed by splicing two pieces of silicon wafers, the lower side of the rectangular channel is a hydrophilic silicon wafer III, the upper side of the rectangular channel is a hydrophilic silicon wafer II, and the front side and the rear side of the rectangular channel are transparent glass sheets; the trace gas pump sends trace gas into the rectangular channel, the microinjection pump injects a liquid column into the rectangular channel, the high-speed camera system performs camera shooting on the inside of the channel, analysis processing is performed on a shot image, the distances between the two positions of the movement of the liquid column and the contact points of the silicone wafer I and the silicone wafer II, and the movement time are measured respectively, the velocities of the liquid column on the surfaces of the two silicone wafers are obtained by dividing displacement by time, and the velocity difference on the two silicone wafers is the slip velocity of the liquid column on the silicone wafer II. The device for measuring the slip velocity under micro-scale has the advantages that an experiment is convenient to implement, post processing is simple, and experimental results are clear and easy to comprehend; repeatability is good; the device for measuring the slip velocity under micro-scale is applicable to micro-fluid systems.

Description

technical field [0001] The invention belongs to the technical field of microfluidic system measurement, and in particular relates to a microfluidic system slip velocity measurement technique, in particular to an image method measurement slip velocity technique. Background technique [0002] With the development of microfluidic systems, research on micro-scale flow has always been a subject of concern. With the development of micro-machines, the flow conditions of micro-channel flow fields have attracted more and more attention. The diameter of these micro-channels often ranges from nanometers to micrometers. Due to the influence of channel wall gravitation and surface topography, the movement characteristics of microfluids are different from the liquid flow characteristics in macroscopic channels. The slip velocity on the wall boundary has attracted more and more attention. At present, the explanation of the drag reduction mechanism of hydrophobic surfaces at home and abroad...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is: the use of the measurement of macroscopic quantities to study microscopic phenomena, its accuracy is affected to a certain extent

With the development of technologies such as flow field quantitative visualization, particle tracking velocimetry, and particle image velocimetry (Particle Image Velocity, PIV), there are methods for directly observing the influence of superhydrophobic surfaces on velocity in the prior art. The disadvantage of this method is : It requires a lot of analysis of data and images, which is more complicated

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