Cheap micro-fluidic device used for diagnosis of syphilis by liquid flow transmission via interfacial characteristics

Abstract

The invention relates to a low-cost microfluidic device for syphilis diagnosis, which uses interface characteristics to transmit liquid flow, and belongs to the field of analysis and testing. There are some difficulties in using cheap and easy-to-process polydimethylsiloxane (PDMS) to make the substrate of the microfluidic chip for syphilis diagnosis; The interior is filled with doped micron-sized titanium dioxide particles; the titanium dioxide particles are titanium dioxide particles that can induce super-hydrophilic properties on the surface through pre-irradiation of visible light; the titanium dioxide particles fill the super-hydrophilic gaps between the particles Collect, compensate, and surpass the original strong hydrophobic pipeline, thereby achieving a constant and super-hydrophilic modification effect; at the same time, a small power ultrasonic wave induces a difference in interfacial tension at both ends of the chip, which in turn promotes The sample liquid flows along the channel of the chip toward the terminal.

Description

technical field [0001] The invention relates to a low-cost microfluidic device for syphilis diagnosis, which uses interface characteristics to transmit liquid flow, and belongs to the field of analysis and testing. Background technique [0002] For the technical background of multi-channel microfluidic syphilis diagnosis, please refer to CN 200910160439.X 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 of this case. [0005] The basic structure of a microfluidic chip includes a substrate etched with channels and ...

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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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