Cheap cholera-diagnosing micro-fluidic unit capable of realizing liquid flow driving based on interfacial characteristics

Abstract

The invention relates to a cheap cholera-diagnosing micro-fluidic unit capable of realizing liquid flow driving based on interfacial characteristics, belonging to the field of analytical testing. A series of obstacles exist in preparation of a substrate for a cholera-diagnosing micro-fluidic chip from cheap and easily workable polydimethylsiloxane (PDMS). According to main points of a technical scheme in the invention, PDMS with an original surface is selected as a substrate; the pipelines of a chip are filled with a micronsized silica particle filler which is used for supporting the inner walls of the pipelines, compensating original hydrophobic pipelines with a set of hydrophilic micro-channels, and extruding and covering the inner wall surfaces of the pipelines so as to reduce the contact between biological macromolecules and the inner wall surfaces; and a minisized ultrasonic transducer is adhered onto the terminal of the chip, and rapid and progressive decrease of ultrasonic intensity is realized in a short distance in virtue of strong ultrasonic wave absorption capacity of PDMS, so interfacial tension difference is formed at two ends of the chip under such induction, and sample liquid flow is thus allowed to flow towards the terminal along the pipelines of the chip.

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, 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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