Cholera-diagnosis-used cheap microflow control device for conducting liquid flow driving through interface characteristics

Abstract

The invention relates to a cholera-diagnosis-used cheap microflow control device for conducting liquid flow driving through interface characteristics and belongs to the field of analytical tests. When polydimethylsiloxane (PDMS) which is cheap and extremely easy to process is adopted to make a substrate of a cholera-diagnosis-used cheap microflow control chip, a series of problems are caused; the surface of the PDMS material is highly hydrophobic, and the effect of targeted surface modification or surface decoration is difficult to endure; the device aims to solve the relevant problems. The device is mainly characterized in that PDMS having the originally-ecological surface is selected for making a substrate, a miniature ultrasonic transducer is arranged at the position, near a sample liquid flow terminal, of a microflow control chip in an attached mode, interfacial tension is lowered through ultrasonic waves, and meanwhile by means of high absorption capacity of PDMS to the ultrasonic waves, so that the effect that the intensity of the ultrasonic waves is gradually decreased within a short distance rapidly is achieved, thereby interfacial tension difference is formed at the two ends of the chip, the pressure difference is formed at the two ends due to the interfacial tension difference, and the pressure difference drives sample liquid flow to flow toward the terminal along a capillary tube channel.

Description

technical field [0001] The invention relates to a low-cost microfluidic device for cholera diagnosis driven by liquid flow based on interface characteristics. The microfluidic device is a special device for diagnosing cholera antigen based on antigen / antibody specific reaction, and belongs to the field of analysis and testing. Background technique [0002] For the technical background of multi-channel microfluidic cholera diagnosis, please refer to CN 200910150930.4 and other invention patent applications. [0003] As far as the overall overview of microfluidic technology itself is concerned, you can refer to the monograph "Illustrated Microfluidic Chip Laboratory" published by the famous microfluidic expert Mr. Lin Bingcheng not long ago, which has been published by Science Press. The past, present, and future prospects of microfluidic technology, etc., have detailed and long-form discussions that go deep into specific details. [0004] So, let's talk about the key issues ...

AI Technical Summary

Problems solved by technology

[0007] But it's not that simple

[0008] First, this polydimethylsiloxane material, the material referred to by the acronym PDMS, is itself a strongly hydrophobic material. Microchannels are built on this material. If the microchannels are not targeted The modification operation of the surface of the channel, then, after the overall assembly is completed, that is, after the cover is covered, because the inner surface of the micro channel in the structure occupies most of the inner surface of the liquid flow channel, then the PDMS micro channel The strong hydrophobic characteristic of the inner surface of the channel is the decisive factor, which will make it very difficult for the polar liquid flow similar to the aqueous solution to pass through, and its flow resistance is so large that even ordinary micropumps are difficult to push. Of course, If the cover sheet also chooses to use the PDMS material, then the problem is basically the same, with little difference; therefore, in the prior art, it is necessary to modify and modify the inner surface of the microchannel on the PDMS material; then , is this modification operation for the inner surface of the PDMS microchannel very troublesome? That's not the problem. What constitutes a serious technical problem is another problem: the PDMS polymer molecules in the bulk phase of the PDMS material substrate have the characteristics of automatic diffusion and migration to the surface. The characteristics of polymer molecules diffusing and migrating to the surface automatically will make the modified state of the inner surface of the microchannel modified by the surface modification unable to maintain for a long enough time, and the microgroove after surface modification The maintenance time of the inner surface state of the channel is roughly only enough to complete the time required for the internal test experiment in the laboratory; in other words, the inner surface of the PDMS microchannel after surface modification or surface modification is formed after modification The surface state of the surface does not last long, but quickly tends to or changes back to the surface state before the surface modification, and returns to the original strongly hydrophobic surface state in a relatively short period of time. Then, just imagine, Can such microfluidic chips be produced in large quantities, stored in large quantities, and widely promoted? The answer is obvious, that is, impossible

This problem has also existed for many years, and so far, it has not been properly solved

Images