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CN-121972246-A - Magnetic bead mixing device for magnetic control liquid drop micro-fluidic system

CN121972246ACN 121972246 ACN121972246 ACN 121972246ACN-121972246-A

Abstract

The invention discloses a magnetic bead mixing device for a magnetic control liquid drop micro-fluidic system, and relates to the technical field of micro-fluidics. The device comprises a magnetic control unit and a mechanical movement unit, wherein the magnetic control unit comprises a magnet and a control mechanism which are arranged outside the system, and the mechanical movement unit comprises a mechanism for driving the chip bearing platform to vibrate. The two units work cooperatively, and the magnetic beads are mixed uniformly in the closed cavity of the chip under the combined action of the magnetic field and the mechanical vibration. The magnetic control unit controls the magnetic field to change, and the mechanical unit drives vibration at a preset frequency. The invention solves the problem of low mixing efficiency in the laminar flow environment in the liquid drop microfluidic system through a nonlinear cooperative mechanism, has simple structure and easy integration, is suitable for scenes needing magnetic bead mixing such as immunodetection, nucleic acid detection and the like, and improves the detection accuracy and the system reliability.

Inventors

  • ZHOU CONGCONG
  • LV CHUAN
  • YE XUESONG

Assignees

  • 浙江大学

Dates

Publication Date
20260505
Application Date
20260212

Claims (10)

  1. 1.A magnetic bead mixing device for a magnetic control droplet micro-fluidic system, the system comprising a chip (2) and a chip carrying platform (1) carrying the chip (2), the device being used for performing a magnetic bead mixing operation on the chip (2), characterized by comprising: The magnetic control unit comprises a magnet (3) arranged outside the system and a magnet control mechanism for controlling the change of a magnetic field, and is used for applying a magnetic field effect on the magnetic beads in the liquid drops in the mixing process; the mechanical movement unit comprises a driving mechanism for driving the chip bearing platform (1) to generate mechanical vibration; wherein the magnetic control unit and the mechanical movement unit are configured to work cooperatively, and the magnetic beads are uniformly mixed in the closed cavity of the chip (2) under the combined action of the magnetic field change and the mechanical vibration.
  2. 2. The magnetic bead mixing device for a magnetic control droplet microfluidic system according to claim 1, wherein the magnet control mechanism is configured to control a distance between a lower surface of the magnet (3) and an upper surface of the chip (2) to be 1-20mm.
  3. 3. The magnetic bead mixing device for the magnetic control liquid drop micro-fluidic system according to claim 1, wherein the driving mechanism is a motor and is configured to drive the chip carrying platform (1) to generate reciprocating vibration at a frequency of 5-30Hz, and the reciprocating vibration comprises linear vibration, swinging, eccentric vibration or micro-amplitude periodic motion.
  4. 4. The magnetic bead mixing device for the magnetic control liquid drop micro-fluidic system according to claim 1, wherein the mechanical movement unit further comprises a traction mechanism for connecting the driving mechanism and the chip carrying platform (1), and the traction mechanism comprises a traction cross rod (4), a transmission shaft (5) and a connecting frame (6).
  5. 5. The magnetic bead mixing device for the magnetic control liquid drop micro-fluidic system according to claim 1, wherein the magnet (3) is a ring magnet, an integral magnet, a spliced magnet or an electromagnet.
  6. 6. A magnetic bead mixing device for a magnetically controlled droplet microfluidic system according to claim 1, characterized in that the magnet control mechanism is configured to control the magnet (3) to remain stationary or to move along a preset single axis of motion during mixing.
  7. 7. The magnetic bead mixing device for a magnetic controlled droplet microfluidic system of claim 1, wherein the magnet control mechanism is configured to generate a magnetic field during mixing and to deactivate the magnetic field before and after mixing.
  8. 8. Use of a magnetic bead mixing device for a magnetic controlled droplet microfluidic system according to any of claims 1-7 in detection of an immune response involving magnetic beads.
  9. 9. Use of a magnetic bead mixing device for a magnetic controlled droplet microfluidic system according to any one of claims 1-7 in detection of nucleic acid reactions in which magnetic beads participate.
  10. 10. Use of a magnetic bead mixing device for a magnetic controlled droplet microfluidic system according to any of claims 1-7 in a droplet microfluidic system requiring magnetic bead mixing or washing.

Description

Magnetic bead mixing device for magnetic control liquid drop micro-fluidic system Technical Field The invention relates to the technical field of microfluidics, in particular to a magnetic bead mixing device for a magnetic control liquid drop microfluidic system. Background The microfluidic technology is a technology for realizing accurate manipulation and analysis of micro-fluid (such as nano-liter to micro-upgrade liquid drops) in a microchip, has the advantages of high portability, strong parallel processing capability, low reagent consumption and the like, and becomes an important platform for biochemical analysis integration and miniaturization. The microfluidic technology based on liquid drops further improves expandability, programmability and operation efficiency by independently controlling discrete liquid drops. The magnetic control droplet microfluidic technology is used as a branch, and the magnetic beads are controlled to collect and transfer between droplets in a non-contact manner by using an external magnetic field, for example, in immunoassay, a magnetic bead coated antibody is combined with a target antigen to form a compound, and detection is completed by transferring and reacting between different chambers, so that the magnetic control droplet microfluidic technology has high flexibility and simplicity. The magnetic bead mixing module is a key component of the system, and the magnetic beads can be uniformly dispersed in the liquid drops by effective mixing, so that the detection accuracy is improved. However, in a microfluidic closed chamber, the flow is in a laminar state due to the low reynolds number of the fluid (typically Re < 1), and the diffusion process is slow. In the absence of external drive, there is little flow inside the droplets and the beads tend to remain in an aggregated state, resulting in inadequate mixing. The existing mixing method is divided into two types, namely passive mixing which relies on a runner geometric structure to induce mixing, but is complex in design, low in efficiency and not suitable for a closed discrete liquid drop microfluidic system, and active mixing which relies on an external source such as mechanical vibration, sound waves, bubble stirring or magnetic force. Mechanical vibration is too slow to disperse the beads effectively in the closed chamber, and high-speed vibration can cause overheating and mechanical losses, affecting instrument life. The mixing of sound waves can cause extrusion of liquid drops to further cause reagent crosstalk to interfere with detection results, the stirring of bubbles requires an additional injection pump, the system is complex, and the size of bubbles is unstable and can influence detection signals (such as photon counting). The magnetic force mixing drives the magnetic beads to realize mixing through the change of an external magnetic field, and the magnetic force mixing device is low in cost and easy to control, so that the magnetic force mixing device is widely focused. However, the complex magnet array occupies a large space and is difficult to integrate, and even dispersion of magnetic beads can not be realized by simple magnet movement (single axis movement or combined movement) and on-off of the electromagnet, so that insufficient reaction or incomplete cleaning is caused, and finally, the detection sensitivity and accuracy are reduced. Therefore, the prior art lacks a simple structure, high efficiency and easy integrated magnetic bead mixing device, and the prior art can not realize rapid and sufficient magnetic bead mixing in a droplet microfluidic environment with limited size and sealed in advance. Disclosure of Invention The invention aims to provide a magnetic bead mixing device for a magnetic control liquid drop micro-fluidic system, which overcomes the defects of the prior art, combines the dynamic change of a magnetic field and the internal flow of liquid drops through the synergistic effect of a magnetic control unit and a mechanical movement unit to realize the efficient dispersion of magnetic beads, has the characteristics of simple structure, high efficiency and easy integration, and can realize rapid and sufficient magnetic bead mixing in a closed micro-fluidic chamber environment. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a magnetic bead mixing device for a magnetic controlled droplet microfluidic system, the system comprising a chip and a chip carrying platform carrying the chip, the device being for performing a magnetic bead mixing operation on the chip, comprising: The magnetic control unit comprises a magnet arranged outside the system and a magnet control mechanism for controlling the change of the magnetic field, and is used for applying the magnetic field effect on the magnetic beads in the liquid drops in the mixing process; The mechanical movement unit comprises a driving mechanism for driving the chip bearing platform to