A control structure of a microfluidic chip

Abstract

The present invention discloses a control structure of a microfluidic chip, including a spherical magnet with a clear NS pole, a rectangular magnet sheet with a clear NS pole, and a driving coil; the spherical magnet is arranged in a fluid chamber, the rectangular magnet sheet and the driving coil are arranged outside the fluid chamber, the rectangular magnet sheet is placed flat on the inner annular surface of the driving coil, a square wave is passed through the driving coil, and the spherical magnet reciprocates in the fluid. The present invention utilizes a square wave current to generate a changing magnetic field to drive the strongly magnetic rectangular magnet sheet to swing, thereby driving the spherical magnet to vibrate with a stronger swinging magnetic field, and realizing different flow directions of the fluid through the vibration of the spherical magnet under different channel conditions. The overall size of the present invention can be controlled within 1 cm, with a small size and low cost, and has scalability and integrability, and can be widely used in chemistry, life sciences, environmental sciences, medical and health fields.

Description

Technical Field

[0001] The invention relates to the field of microfluidics, and in particular to a control structure of a microfluidics chip. Background Art

[0002] Microfluidics is a technology that precisely controls and manipulates microscale fluids, especially submicron structures. Microfluidic chips use semiconductor-like microelectromechanical processing technology to build a microfluidic system on the chip, transferring the experimental and analytical processes to a chip structure composed of interconnected paths and liquid chambers. After loading biological samples and reaction solutions, micromechanical pumps, electrohydraulic pumps, and electroosmotic flow are used to drive the flow of buffer solutions in the chip to form a microfluidic path, and perform one or multiple reactions on the chip.

[0003] There are many ways to classify micropumps: according to whether there is a movable valve plate, they can be divided into valved micropumps and valveless micropumps; according to different driving methods, they can be divided into piezoelectric, electrostatic, pneumatic, thermal drive, etc. Valved micropumps generally work by using the periodic change of cavity volume and one-way valves. The principle of valved micropumps is simple, the manufacturing process is relatively mature and easy to control, and it is the mainstream of current applications. However, due to the presence of mechanical components such as valve plates in the pump body, the fatigue and life of the valve plates have always been a problem that has troubled researchers, greatly limiting its scope of application; and the processing technology and processing accuracy of these mechanical movable components limit the further miniaturization of valved micropumps, which are not suitable for the technical requirements of microfluidic chips that have developed rapidly in recent years. Compared with valved micropumps, valveless micropumps have unique development advantages and broad application prospects due to their novel principles, relatively simple structures, low manufacturing process requirements, and suitability for miniaturization.

[0004] Patent 201310378611.5 proposes "a traveling wave valveless micro pump based on the coordinated drive of a rotating micromagnetic array", which uses the interaction of two sets of micromagnetic arrays to generate four standing waves with the same amplitude, frequency, and vibration direction, but with a phase difference of 90 degrees on the pipeline. Since the four columns of standing waves can synthesize traveling waves on the microfluidic pipeline, the liquid in the pipeline flows along the traveling wave direction. The two sets of micromagnet arrays are composed of four annular magnets and cylindrical magnets respectively. The size of the annular magnet is 2mm high, 1mm in diameter, and 2.3mm in outer diameter. The size of the cylindrical magnet is 2mm high and 1mm in diameter. The size of the motor is 6mm in diameter and 14mm in length. The overall size of the entire microfluidic pump is about 3cm, which is still too large and not suitable for the more delicate microfluidic field. Summary of the invention

[0005] The present invention provides a control structure of a microfluidic chip to realize the simplest driving structure of microfluids.

[0006] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0007] A control structure of a microfluidic chip is characterized by comprising a spherical magnet with a clear NS pole, a rectangular magnet sheet with a clear NS pole and a driving coil; the spherical magnet is arranged in a fluid cavity, the rectangular magnet sheet and the driving coil are arranged outside the fluid cavity, the rectangular magnet sheet is placed flat on the inner ring surface of the driving coil, a square wave is passed through the driving coil, and the spherical magnet reciprocates in the fluid.

[0008] The present invention uses a square wave current to generate a changing magnetic field to drive a strongly magnetic rectangular magnet sheet to swing, thereby driving the spherical magnet to vibrate with a stronger swinging magnetic field, and realizing different flow directions of the fluid through the vibration of the spherical magnet under different channel conditions. The overall size of the present invention can be controlled within 1 cm, with a small volume, low cost, scalability and integrability, and can be widely used in the fields of chemistry, life sciences, environmental sciences, medical care and health. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the basic composition structure of the present invention.

[0010] Figure 2 is an action schematic diagram of the present invention, wherein: Figure 2 a is a schematic diagram of the initial state, Figure 2 b is the schematic diagram of the movement of the magneton when the magnet rotates clockwise. Figure 2 c is the schematic diagram of the movement of the magneton when the magnet rotates counterclockwise. Figure 2 d is a schematic diagram of the movement of magnets and magnons under square wave current.

[0011] Figure 3 It is a schematic diagram of the entity of Example 1 of the present invention.

[0012] Figure 4 is a schematic diagram of the flow field generated by an oscillator under various boundary conditions, where Figure 4 a is the several position lines of the oscillator; Figure 4 b is a schematic diagram of the slow vibration of the magneton suspended in the fluid (i.e. without boundaries). Figure 4 c is a schematic diagram of rapid vibration without boundaries; Figure 4 d is a schematic diagram of the flow field when the oscillator rapidly vibrates in the direction parallel to the vertical single boundary; Figure 4 e is a schematic diagram of the flow field when the oscillator vibrates rapidly in a direction parallel to the vertical boundary at the angular boundary position; Figure 4 f is a schematic diagram of the flow field when the oscillator vibrates rapidly perpendicular to the single boundary direction.

[0013] Figure 5 It is a schematic diagram of the superposition of multiple oscillators and flow fields. Figure 5 a is an oscillator, Figure 5b are two oscillators, Figure 5 c is 3 oscillators, Figure 5 d is 4 oscillators.

[0014] Figure 6 It is a structural diagram of the microfluidic chip for audio input.

[0015] In the figure, 1 is a spherical magnet, 2 is a rectangular magnet sheet, 3 is a driving coil, 4 is a partition wall, 5 is a loop channel, and 6 is an audio cable. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0017] Figure 1-6 It is the preferred embodiment of the present invention. The present invention is a microfluidic pump for driving a cavity fluid, comprising a spherical magnet 1 with a clear NS pole, a rectangular magnet sheet 2 with a clear NS pole, and a driving coil 3; the spherical magnet 1 is placed in the fluid cavity, and the rectangular magnet sheet 2 and the driving coil 3 are driving bodies, which are arranged outside the fluid cavity, that is, there is a partition wall 4 (also called a boundary) between the rectangular magnet sheet 2 and the driving coil 3 and the spherical magnet 1. The spherical magnet 1 will be adsorbed by the rectangular magnet sheet 2 on the nearest inner wall of the cavity, and when the buoyancy is constant, the spherical magnet 1 can be suspended in the fluid. The rectangular magnet sheet 2 is placed flat on the inner annular surface of the driving coil 3, and the driving coil 3 has the ability to drive the rectangular magnet 2 to rotate or swing. Figure 3 This is a schematic diagram of a specific embodiment of the present invention. The spherical magnet 1, the rectangular magnet piece 2 and the driving coil 3 are all purchased on the market. This embodiment uses a spherical magnet 1 with a diameter of 2mm, a rectangular magnet piece 2 with a length of 4.5mm, and a driving coil 3 with an inner circle width of 5mm and a length of 3mm. The rectangular magnet piece 2 is placed in the driving coil 3. The overall size of the entire experimental device does not exceed 1cm, which is much smaller than the volume of other microfluidic pumps. The spherical magnet 1, the rectangular magnet piece 2 and the driving coil 3 can be expanded in size as needed.

[0018] After the driving coil 3 is energized, the positions of the N pole and the S pole of the rectangular magnet piece 2 will change by adjusting the current, thereby causing the position of the spherical magnet 1 to change, such as Figure 2 As shown, with the center of the rectangular magnet piece 2 as the swing fulcrum, when the driving coil 3 is energized in the forward direction, the N-pole of the rectangular magnet piece 2 swings clockwise toward the spherical magnet 1; when the driving coil 3 is energized in the reverse direction, the S-pole swings counterclockwise toward the spherical magnet 1; when the input current of the driving coil 3 is a square wave current, the rectangular magnet piece 2 swings regularly with the center as the fulcrum, and the change in magnetic force causes the spherical magnet 1 on the other side of the partition wall 4 to reciprocate in a direction parallel to the rectangular magnet piece 2.

[0019] The flow field generated by the vibration of the spherical magneton 1 under various boundary conditions is as follows: Figure 4 As shown, it can be seen that when there is no boundary (that is, the oscillator is located in the fluid), the flow field around the oscillator will generate 4 vortices ( Figure 4 b and Figure 4 c), while in the case of a single boundary, the flow field around the oscillator generates two vortices with different vibration directions and vortex shapes, such as Figure 4 d and Figure 4 f, when the vibrator is located at the corner boundary, it is affected by the partition wall 4 and the vortex flow field formed is smaller.

[0020] Due to the small size of the spherical magneton 1, a vibrator pump only needs 0.248mw of energy at minimum, and driving the vibration of four spherical magnetons only requires less than 1mW of power consumption. This embodiment uses sound waves as the driving source and designs a dual-pump microchip to connect to an external audio output device, such as Figure 6 As shown, the microchip has an internal circulation channel 5, and the circulation channel 5 is filled with liquid. The chip is installed in the middle of a double-pump plastic driver in the shape of a hand mirror, and has a 3.5 mm audio jack. Two spherical magnets 1 are placed in the circulation channel 5, and two driving coils 3 (containing rectangular magnet pieces 2) are placed outside the circulation channel 5 near the two spherical magnets 1, as shown in FIG. Figure 6 As shown, two spherical magnets 1 are placed on the left and right sides of the circulation channel 5 to form a left pump and a right pump. The driving coils of the left and right pumps are directly connected to the left and right channels of the external audio output respectively. When playing stereo music, the left or right electrical audio signal reaches the left pump or the right pump respectively through the 3.5 mm audio cable 6. The two vibrator pumps are equivalent to two headphones. By changing the audio output file to a square wave file, effective driving can be achieved.

[0021] The present invention utilizes a vibrator to drive microfluids. The vibrator drive is to generate positive pressure in the direction of the vibration axis and negative pressure in all directions on the plane orthogonal to the vibration axis through a localized vibrating vibrator, thereby driving the fluid to move. The audio square wave is used to generate a changing magnetic field to drive the swing of the strong magnetic rectangular magnet piece 2, thereby driving the vibration of the spherical magnet 1 with a stronger swinging magnetic field to complete the vibrator vibration action. The present invention is a fully sealed non-contact type, which uses a magnetic field to control the vibration of the vibrator or the rotation of the rotor. This is the preferred method for penetrating a partition wall for control. The spherical magnet 1 can be selected according to the working temperature, and it can work normally under harsh environmental conditions with very high temperatures.

[0022] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the present invention.

Claims

1. A control structure of a microfluidic chip, characterized in that: It includes a spherical magnet with a clear NS pole, a rectangular magnet sheet with a clear NS pole and a driving coil; the spherical magnet is arranged in a fluid cavity, the rectangular magnet sheet and the driving coil are arranged outside the fluid cavity, the rectangular magnet sheet is placed flat on the inner ring surface of the driving coil, a square wave is passed through the driving coil, and the spherical magnet reciprocates in the fluid; the spherical magnet is placed in a microchip with a circulation channel, the driving coil and the rectangular magnet sheet are arranged outside the circulation channel, the driving coil is connected to an external audio output device through an audio cable, the audio input by the audio cable is a square wave input, and the audio square wave is used to generate a changing magnetic field to drive the swing of the strongly magnetic rectangular magnet sheet, thereby driving the vibration of the spherical magnet.

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