Micro-fluidic chip device containing PDMS substrate and based on double drive coupling mode

Abstract

The invention relates to a micro-fluidic chip device containing a PDMS (polydimethylsiloxane) substrate and based on a double drive coupling mode, and belongs to the field of analysis and testing. When cheap and extremely-easily-processed polydimethylsiloxane (PDMS) is used to manufacture a substrate of a microfluidic chip, in fact a series of difficult problems exist. Key points of the technicalscheme are as follows: PDMS with an original ecological surface is used as the substrate, a chain-ring-type electromagnetic fixture which is equipped with a micro ultrasonic transducer is located at aposition near to a sample fluid flow tail end of the microfluidic chip in a sleeving manner, driving force based on an interfacial tension difference is formed by inducing of supersonic waves, and the driving force is coupled with driving force of a micro pump to synergistically drive sample fluid flows to flow towards a tail-end direction of the sample fluid flows, the interiors of pipelines ofthe chip are filled with a micron-sized silicon dioxide particle filler, and functions of the filler comprise the following aspects: supporting inner walls of the pipelines, using collection of hydrophilic micro flow channels to replace and compensate original hydrophobic pipelines, and squeezing and covering the inner wall surfaces of the pipelines to reduce contact opportunity of biomacromolecules and the inner wall surfaces.

Description

Technical field [0001] The invention relates to a microfluidic chip device containing a PDMS substrate based on a dual drive coupling mode, which 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. This monograph has been published by Science Press. The past, present, and future prospects of flow control technology are all detailed and detailed long discussions. [0003] The fields that microfluidic chips are often applied to include various analysis and detection of sample solutions containing biological macromolecules. [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, before the cover sheet is assembled, appear to be some The chann...

AI Technical Summary

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

[0016] Third, as mentioned above, the inner surface of the PDMS channel is strongly hydrophobic, and targeted surface chemical modification or surface chemical modification is difficult to last. It is effective to use it within a short period of time; if the relatively short expiration date has passed and it is still used forcibly, since the surface state is already close to the hydrophobic state, there must be a relatively large liquid flow driven by the conventional micropump. In this way, the sample liquid can only be forced to flow in the target direction by increasing the pumping power and pumping pressure of the micropump. Sending pressure to pump the sample liquid flow will cause bubbling, puffing, twisting, and deformation of the channel at the sampling end of the substrate, including the area near the sampling end, and, under such high pressure conditions, in the The channel and its periphery at the injection end and its vicinity are also prone to peeling between the substrate and the cover slip. In this case, the sample solution will enter the gap between the substrate and the cover slip formed after the peeling. This actually leads to the damage of the microfluidic chip; of course, if the surface modification or surface modification is not in place, it will also lead to the above-mentioned situation within the short customary validity period; In the case of an external micropump for liquid flow drive, the above-mentioned problem always exists

As mentioned above, if no pre-operations such as surface modification or surface modification have been done at all, then the above-mentioned problem will be more serious, even if there is no channel bubbling at the injection end and its vicinity, Problems such as puffing, twisting, deformation, and peeling between the substrate and the cover sheet, etc., just because the flow resistance is too large, the use of a high-pressure micropump may not be able to drive the sample liquid flow toward the terminal.

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