Cheap micro-fluidic device used for diagnosis of AIDS by novel mode liquid flow transmission

Abstract

The invention relates to a low-cost microfluidic device for AIDS diagnosis which transmits liquid flow in a new way, and belongs to the field of analysis and testing. There are technical obstacles in making the substrate of the microfluidic chip for AIDS diagnosis with cheap and easy-to-process polydimethylsiloxane (PDMS). The main point of this case is that the substrate is made of PDMS with an original ecological surface, and the pipes of the chip are filled with doped micron-sized titanium dioxide particles; the titanium dioxide particles are titanium dioxide that can induce superhydrophilic properties on the surface through pre-irradiation of visible light Particles; the collection of super-hydrophilic gaps between the particles of the titanium dioxide particle filler compensates and surpasses the original strong hydrophobic channels, thereby achieving a constant and super-hydrophilic modification effect; at the same time, with a small power The ultrasonic wave induces a difference in interfacial tension at the first and last ends of the chip, and then promotes the flow of the sample liquid along the channel of the chip to the direction of the terminal.

Description

Technical field [0001] The invention relates to a cheap microfluidic device for AIDS diagnosis that transmits liquid flow in a new way, and belongs to the field of analysis and testing. Background technique [0002] For the technical background of multi-channel microfluidic AIDS diagnosis, please refer to CN 200910151219.0 and other invention patent applications. [0003] For the overall overview of microfluidic technology itself, you can refer to the monograph "Illustrated Microfluidic Chip Lab" recently published by the famous microfluidic expert Mr. Lin Bingcheng. This monograph has been published by Science Press. The past, present, and future prospects of microfluidic technology are all detailed and detailed long discussions. [0004] So, let's talk about the key issues of concern in this case. [0005] The basic structure of a microfluidic chip includes a substrate etched with channels and a cover sheet attached to it. The liquid flow channels on the substrate, before the cover...

AI Technical Summary

Problems solved by technology

[0007] But it's not that simple

[0008] First, this polydimethylsiloxane material, which is referred to by the acronym PDMS, is itself a strongly hydrophobic material, and channels are built on this material. modification operation, then, after the overall assembly is completed, that is, after the cover is covered, because the inner surface of the channel in the structure occupies most of the inner surface of the liquid flow channel, then the inner surface of the PDMS channel is The strong hydrophobicity is the decisive factor, it will make it very difficult for the polar liquid fine flow similar to the aqueous solution to pass through, and its flow resistance is so large that even the general micropump is difficult to push, of course, if the cover sheet is also If you choose to use the PDMS material, then the problems are basically the same, with minor differences; therefore, in the prior art, it is necessary to modify and modify the inner surface of the channel on the PDMS material; then, this is for the PDMS channel Is the modification operation of the inner surface of the channel 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 channel modified by the surface unable to maintain for a long enough time. The maintenance time of the internal surface state is roughly only enough to complete the time required for the internal test experiment in the laboratory; in other words, the surface state of the PDMS channel inner surface after surface modification or surface modification is formed after modification It cannot last for a long time, but it will automatically tend to or change back to the surface state before the surface modification, and return to the original strongly hydrophobic surface state in a short period of time. Then, just imagine, such a slight Can flow control 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

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