Microfluidic chip device depending on interphase interface characteristics to achieve sample fluid transfer

Abstract

The invention relates to a microfluidic chip device depending on interphase interface characteristics to achieve sample fluid transfer, which belongs to the field of analytical testing. In practice, certain problems exist in using cheap and extremely easy-to-process polydimethylsiloxane (PDMS) to produce a substrate of a microfluidic chip. The microfluidic chip device is characterized in that PDMS with the original surface is chosen by the substrate, ducts of a chip are filled up with micron-sized silicon dioxide particle filler, and the functions of the filler include supporting the internal walls of the ducts, using a set of hydrophilic microchannels to compensate original hydrophobic ducts and squeezing and covering the internal wall surfaces of the ducts in order to reduce the chance of contact between biomacromolecules and the internal wall surfaces; a miniature ultrasonic transducer is mounted on a terminal of the chip in an attaching manner, the strong ultrasonic absorption of the PDMS is utilized to rapidly decrease ultrasonic intensity within a short distance, thereby an interface tension difference is induced to be formed at both ends of the chip, and sample fluid is then promoted to flow in a direction toward the terminal along the ducts of the chip.

Description

technical field [0001] The invention relates to a microfluidic control chip device that realizes liquid flow transmission of a sample relying on interphase interface characteristics, and belongs to the field of analysis and testing. Background technique [0002] For the overall overview of microfluidic technology itself, 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 fluidic technology, etc., all have detailed and long-form expositions that go deep into specific details. [0003] The fields where microfluidic chips are often applied include various analysis and detection of sample solutions containing biomacromolecules. [0004] 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 a...

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Problems solved by technology

[0006] But it's not that simple

[0007] 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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