Passive convergence-diffusion micro-mixer for fluids with low diffusion coefficient

Abstract

The invention belongs to the field of miniaturized total analysis systems and fluid micro-mixing and relates to a passive convergence-diffusion micro-mixer for fluids with low diffusion coefficient. The micro-mixer is composed of a fluid inlet channel, a fluid mixing channel and a fluid outlet channel; polygonal structural units are repeatedly arranged in the fluid mixing channel; the polygonal structural units are arranged in a staggered form, so that a convergence-diffusion chamber structure is formed on tooth-shaped edges of the polygonal structural units and a mixing chamber structure is formed on the top ends of the polygonal structural units; the convergence-diffusion chamber structure is capable of inducing the fluid to change periodically, so as to form a convergence-diffusion flowvariable; convergence-diffusion effect and sharp corner effect of the mixing chamber structure are utilized to induce the fluid to generate other various mixing mechanisms except for diffusion mechanism in the mixing chamber. The passive convergence-diffusion micro-mixer provided by the invention is capable of realizing fast and efficient mixing between fluids with low diffusion coefficient in awide range of reynolds number.

Description

technical field

[0001] The invention belongs to the field of micro-total analysis system, micro-fluid mixing and related fields, and relates to a passive convergent-divergent micro-mixer for fluid with low diffusion coefficient. Background technique

[0002] With its unique advantages such as miniaturization, integration, and less sample consumption, microfluidic devices are widely used in the fields of biology and chemistry, including biochemical analysis, medical diagnosis, genetic testing, and drug development. At the microscopic scale, the fluid in the microchannel is mainly in the state of laminar flow, and the mixing between the fluids in the natural state depends entirely on the molecular diffusion between the fluid layers with different concentrations. Diffusion mixing itself is a slow and inefficient process, requiring considerable time and sufficiently long channels to achieve effective mixing. According to Fick's law, the total time required for diffusion is inve...

Examples

Embodiment Construction

[0048] The specific implementation manners of the present invention will be further described below in conjunction with the accompanying drawings and technical solutions.

[0049] The present invention proposes a passive convergent-divergent micro-mixer for fluids with low diffusion coefficient. The mixer is made of polydimethylsiloxane (PDMS). The channel structure pattern is transferred to a single crystal silicon wafer to obtain a positive mold; then the PDMS stock solution and the curing agent are mixed evenly at a ratio of 10:1, and the air bubbles in the PDMS mixed solution are discharged using a vacuum drying oven and then applied to the mold, and then vacuumed again Remove the air bubbles on the mold, and then heat at a constant temperature of 80°C for two hours; finally, peel off the heated and cured PDMS from the single crystal silicon wafer in absolute ethanol, then clean it with deionized water, and dry it with nitrogen gas for later use. Permanently bond the PDMS ...

technical field

[0001] The invention belongs to the field of micro-total analysis system, micro-fluid mixing and related fields, and relates to a passive convergent-divergent micro-mixer for fluid with low diffusion coefficient. Background technique

[0002] With its unique advantages such as miniaturization, integration, and less sample consumption, microfluidic devices are widely used in the fields of biology and chemistry, including biochemical analysis, medical diagnosis, genetic testing, and drug development. At the microscopic scale, the fluid in the microchannel is mainly in the state of laminar flow, and the mixing between the fluids in the natural state depends entirely on the molecular diffusion between the fluid layers with different concentrations. Diffusion mixing itself is a slow and inefficient process, requiring considerable time and sufficiently long channels to achieve effective mixing. According to Fick's law, the total time required for diffusion is inve...

Examples

Embodiment Construction

[0048] The specific implementation manners of the present invention will be further described below in conjunction with the accompanying drawings and technical solutions.

[0049] The present invention proposes a passive convergent-divergent micro-mixer for fluids with low diffusion coefficient. The mixer is made of polydimethylsiloxane (PDMS). The channel structure pattern is transferred to a single crystal silicon wafer to obtain a positive mold; then the PDMS stock solution and the curing agent are mixed evenly at a ratio of 10:1, and the air bubbles in the PDMS mixed solution are discharged using a vacuum drying oven and then applied to the mold, and then vacuumed again Remove the air bubbles on the mold, and then heat at a constant temperature of 80°C for two hours; finally, peel off the heated and cured PDMS from the single crystal silicon wafer in absolute ethanol, then clean it with deionized water, and dry it with nitrogen gas for later use. Permanently bond the PDMS ...

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