An on-chip enhanced mixing device using reciprocating flow and acoustic flow

Abstract

The present invention relates to the field of microfluidic enhanced mixing technology, and in particular to an on-chip mixing enhancement device using reciprocating flow and acoustic flow, comprising multiple groups of liquid inflow channels, a T-shaped channel, an acoustic vortex mixing enhancement channel, two piezoelectric vibrators and a mixed liquid outlet; the entire device is etched on a chip substrate to form a corresponding channel structure. The present invention utilizes multiple driving chambers to generate reciprocating flows with opposite phases in conjunction with a microchannel T-shaped structure, so that a multi-layer overlapping distribution pattern is formed between solutions, thereby increasing the contact area between different solutions, and then ultrasound is used to form acoustic vortices in a non-shaped tube, so that a flow across a concentration gradient is generated in the multi-layer overlapping distribution of solutions, thereby enhancing the solute transfer between different solutions. This device combines reciprocating flows of different phases with a T-shaped channel for the first time. At the same time, the device has a simple structure, a small size, a high degree of integration, and good versatility, and therefore has good application prospects and use value.

Description

Technical Field

[0001] The invention relates to the technical field of microfluidic enhanced mixing, in particular to an on-chip mixing enhancement device utilizing reciprocating flow and acoustic flow. Background Art

[0002] Microfluidic enhanced mixing technology is conducive to the formation of a uniform mixed solution due to its precisely controllable flow rate, rapid micro-mixing, and efficient mass / heat transfer at the micron level. It provides a new approach to solving technical problems such as the precise regulation of solution mixing and molecular motion. Therefore, microfluidic enhanced mixing technology has an important influence and great application value in the regulation and enhancement of solution mixing processes, and has application potential in many chemical fields. Therefore, related systems involving microfluidic enhanced mixing technology have extremely broad application prospects.

[0003] At present, the system integration related to microfluidic enhanced mixing technology has yet to be optimized. Most chips rely on complex and large external structures to achieve the required functions. These structures are contrary to the characteristics of this system, which is small in size and easy to use, and greatly limit the application scope of this technology.

[0004] Therefore, there is an urgent need to propose a micro-sized enhanced mixing device with enhanced mixing effect, high mixing efficiency, simple structure, small size and high integration. Summary of the invention

[0005] The technical problem solved by the present invention is to overcome the existing defects and provide a microfluidic on-chip enhanced mixing device that combines reciprocating flow with a microchannel T-shaped structure channel and acoustic vortex. Multiple driving chambers are used to generate reciprocating flow with opposite phases in combination with a microchannel T-shaped structure, so that a multi-layer overlapping distribution pattern is formed between the solutions, thereby increasing the contact area between different solutions. Ultrasound is then used to form acoustic vortices in a non-shaped tube, so that a flow across the concentration gradient is generated in the multi-layer overlapping distribution of solutions, thereby enhancing the solute transfer between different solutions. This device combines reciprocating flows of different phases with a T-shaped channel for the first time. At the same time, the device has a simple structure, a small size, a high degree of integration, and good versatility, so it has good application prospects and use value.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] An on-chip enhanced mixing device using reciprocating flow and acoustic flow includes multiple groups of liquid inflow channels, a T-shaped channel, an acoustic vortex mixing enhancement channel, two piezoelectric vibrators and a mixed liquid outlet; the entire device is etched on a chip substrate to form a corresponding channel structure.

[0008] The liquid inflow channel comprises a liquid inlet, an inlet channel, a driving chamber and an elastic membrane; the driving chamber and the liquid inlet are top opening structures, and the elastic membrane covers the top opening of the driving chamber; one end of the driving chamber is connected to the liquid inlet through the inlet channel, and the other end is connected to the T-shaped channel;

[0009] The T-shaped channel comprises a transverse channel and a vertical channel, and a plurality of interfaces are symmetrically arranged on the transverse channel for communicating with the driving chamber of each group of liquid inflow channels;

[0010] The mixed liquid outlet is a top opening structure;

[0011] The acoustic vortex mixing and enhancement channel is a symmetrical "non"-shaped structure, with a straight main channel in the middle and symmetrical side channels on both sides, and the main channel and the side channels are 90°; the acoustic vortex mixing and enhancement channel has its inlet end connected to the tail end of the vertical channel of the T-shaped channel, and its outlet end connected to the mixed liquid outlet.

[0012] The piezoelectric vibrator is symmetrically bonded on both sides of the acoustic vortex mixing enhancement channel, and the distance from the center line of the acoustic vortex mixing enhancement channel is 3-5 times the cross-sectional width of the narrow part of the acoustic vortex mixing enhancement channel.

[0013] The multiple groups of liquid inflow channels are symmetrically arranged, and the number is determined by the amount of liquids to be mixed.

[0014] The liquid inlet, the inlet channel, the driving chamber, the T-shaped channel, the acoustic vortex mixing and strengthening channel and the mixed liquid outlet are located on the same horizontal plane.

[0015] Basic principles of the present invention:

[0016] The present invention uses an electromagnetically driven elastic membrane to produce a reciprocating flow. Reciprocating flow is used to solve the problem of liquid mixing efficiency. Reciprocating flow is a phenomenon in which the liquid flow rate changes periodically between a maximum value and a minimum value over time. Since the device has multiple driving chambers to generate reciprocating flows with opposite amplitudes, the multiple liquids to be mixed enter the acoustic vortex mixing enhancement channel through the T-shaped channel in turn, forming a multi-layer overlapping distribution pattern, which increases the contact area between the two solutions, thereby enhancing the diffusion of the two solutes and further enhancing the mixing effect.

[0017] Acoustofluidics is a technology that combines acoustics with microfluidics, using sound waves as a driving force to manipulate fluids or particles in microchannels, and can be used to enhance the mixing effect of fluids. The present invention uses piezoelectric vibrators and acoustofluidics technology to manipulate fluids in non-shaped tubes through acoustic flow to form acoustic vortices, thereby enhancing the mixing effect of the fluid. In addition, the present invention further enhances the mixing of solutions by using an acoustic vortex mixing enhancement channel in conjunction with a piezoelectric vibrator. When the liquid enters the acoustic vortex mixing enhancement channel, the first layer of vortex structure is generated due to the "non"-shaped structure of the acoustic vortex mixing enhancement channel, and then the piezoelectric vibrator creates an acoustic vortex on the basis of the first layer of vortex structure, generating a more complex vortex structure, thereby generating a flow in a direction perpendicular to the solute concentration gradient between the two overlapping solutions, and enhancing the mixing effect of the solutions through convection between the two solutions.

[0018] The present invention has the following beneficial effects:

[0019] 1. Enhanced mixing effect and high mixing efficiency. The present invention utilizes an on-chip enhanced mixing device that combines reciprocating flow with a microchannel T-shaped structure channel and acoustic vortex, and utilizes two driving chambers to generate reciprocating flow with opposite phases in combination with a microchannel T-shaped structure, so that a multi-layer overlapping distribution pattern is formed between the solutions, thereby increasing the contact area between different solutions, and then ultrasound is used to form acoustic vortexes in the non-shaped tube, so that a flow across the concentration gradient is generated in the multi-layer overlapping distribution solution, thereby enhancing the solute transfer between different solutions, thereby greatly increasing the mixing effect and improving the mixing efficiency.

[0020] 2. Small size and high integration. The present invention integrates the driving and mixing of microfluids, greatly reducing the product volume while ensuring the mixing effect. Two driving chambers are used to generate reciprocating flows with opposite phases, which work together with the T-shaped channel to increase the contact area and preliminarily mix the solution, and then the non-shaped tube and acoustic flow are used to induce the unstable state of flow, thereby further promoting the mixing of the solution. By using an elastomeric membrane, the present invention simplifies the reciprocating flow device into two micro-driving chambers, greatly reducing the volume of the device.

[0021] 3. The mixing effect is easy to adjust. By adjusting the reciprocating flow frequency through electrical signals, the thickness of each layer of the multi-layer overlapping distribution pattern in the microchannel T-shaped structure can be adjusted, thereby adjusting the liquid contact area and adjusting the mixing effect of the liquid. In this way, the present invention can freely and conveniently adjust the mixing effect or reaction time of the liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The schematic diagram of the structure of an on-chip enhanced mixing device using reciprocating flow and acoustic flow according to the present invention.

[0023] Figure 2The cross-sectional structure diagram of an on-chip enhanced mixing device utilizing reciprocating flow and acoustic flow according to the present invention.

[0024] FIG. 3( a ) and FIG. 3( b ) are schematic diagrams showing the working principle of a T-shaped channel of an on-chip enhanced mixing device utilizing reciprocating flow and acoustic flow according to the present invention.

[0025] Figure 4 The present invention is a schematic diagram of the structure of a non-zigzag acoustic vortex mixing enhancement channel of an on-chip enhanced mixing device using reciprocating flow and acoustic flow.

[0026] Figure 5 It is a schematic diagram of the piezoelectric vibrator of an on-chip enhanced mixing device using reciprocating flow and acoustic flow in the present invention to generate an acoustic vortex effect in a non-shaped acoustic vortex mixing and enhancement channel.

[0027] In the figure: 1 left liquid inlet, 2 left inlet channel, 3 left elastic membrane, 4 left driving chamber, 5 right liquid inlet, 6 right inlet channel, 7 right elastic membrane, 8 right driving chamber, 9 T-shaped channel, 10 acoustic vortex mixing enhancement channel, 11 mixed liquid outlet, 12 piezoelectric vibrator. DETAILED DESCRIPTION

[0028] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0029] The on-chip enhanced mixing device of the present invention using reciprocating flow and acoustic flow can mix multiple solutions. This embodiment is described by taking the mixing of two solutions as an example. Figure 1 and Figure 2 As shown, it includes a left liquid inlet 1, a left inlet channel 2, a left elastic membrane 3, a left driving chamber 4, a right liquid inlet 5, a right inlet channel 6, a right elastic membrane 7, a right driving chamber 8, a T-shaped channel 9, an acoustic vortex mixing enhancement channel 10, a mixed liquid outlet 11, and a piezoelectric vibrator 12; the left driving chamber 4 and the right driving chamber 8 are respectively covered by the left elastic membrane 3 and the right elastic membrane 7 to form a chamber whose volume can be changed by an electrical signal.

[0030] Take the left side as an example: the main body of the left driving chamber 4 is circular, and its left and right ends are respectively connected to the left inlet channel 2 and the horizontal part of the T-shaped channel 9, and the center line of the connection position is located on the same straight line passing through the center of the driving chamber 4, and the left inlet channel 2 is connected to the left liquid inlet 1.

[0031] The tail end of the vertical portion of the T-shaped channel 9 is connected to the inlet of the acoustic vortex mixing and intensification channel 10 , and the outlet of the acoustic vortex mixing and intensification channel 10 is connected to the mixed liquid outlet 11 .

[0032] During mixing, the mixing device of the present invention is placed on the oscillator, and solution a and solution b are respectively injected from the left liquid inlet 1 and the right liquid inlet 5, and then the oscillator and the piezoelectric vibrator 12 are started. The working process is as follows:

[0033] Solution a enters the left driving chamber 4 from the left liquid inlet 1 through the left inlet channel 2, and solution b enters the right driving chamber 8 from the right liquid inlet 5 through the right inlet channel 5; start the power supply, and input simple harmonic signals with opposite phases to the elastic membrane a3 and the elastic membrane b7 respectively to cause them to produce regular deformations, so that the solutions in the left driving chamber 4 and the right driving chamber 8 form a reciprocating flow with opposite oscillation phases. Driven by the reciprocating flow with opposite phases, solution a and solution b enter the acoustic vortex mixing enhancement channel 10 through the T-shaped channel 9 in turn. Driven by the reciprocating flow with opposite phases, an interlaced laminar structure is formed for solutions a and solution b in the T-shaped channel 9. After passing through the T-shaped channel 9 to increase the contact area and undergo preliminary mixing, solutions a and b enter the acoustic vortex mixing enhancement channel 10 for further mixing. The structure of the acoustic vortex mixing enhancement channel 10 is shown as follows: Figure 4 As shown, it has a "non"-shaped structure. In the acoustic vortex mixing enhancement channel 10, due to the flow velocity difference and the acoustic flow generated by the piezoelectric vibrators 12 on both sides, vortices are generated, which further disrupt the laminar flow state of the solution, and under the influence of the acoustic flow, the solution generates a velocity component along the concentration gradient direction, thereby improving the mixing effect. Finally, the mixed solution flows out from the mixed solution outlet 11.

[0034] Among them, the mixing of the two solutions in the T-shaped channel 9 when they flow in different directions is as shown in Figures 3(a) and 3(a). Due to the drive of the reciprocating flow with opposite phases, the two solutions in the T-shaped channel 9 form the laminar flow structure shown. Usually, two different solutions generally flow in parallel or parallel when entering the T-shaped channel. In this case, the ability of the T-shaped channel to increase the contact area of ​​the solution is limited by the length and cross-sectional area of ​​the T-shaped channel. Therefore, if the use effect of the T-shaped channel is to be enhanced, the volume of the T-shaped channel can generally only be increased, which is often the reason why the volume reduction of the on-chip laboratory is limited. In addition, since the volume of the T-shaped channel 9 cannot be changed on the chip, when facing the mixing requirements of different solutions, it is often necessary to manufacture multiple on-chip mixing devices with T-shaped channels of different volumes. In summary, the traditional on-chip mixing device with a T-shaped channel is large in size and complicated to use, and it is urgent to propose an on-chip mixing device that can improve the mixing effect under a limited volume. The present invention combines two reciprocating flows with the same period and opposite phases with a T-shaped channel 9 with a length of a, a width of b and a height of c. In this way, the contact area of ​​the solution will increase by 2bc per oscillation period T. By shortening the oscillation period, the contact area of ​​the solution can be maximized in a limited volume, thereby greatly improving the mixing effect of the solution.

[0035] The fluid flow inside the acoustic vortex mixing enhancement channel 10 is as follows: Figure 4 As shown, the acoustic vortex mixing and strengthening channel 10 is a "non"-shaped tube, and piezoelectric vibrators 12 are arranged on both sides; under the action of the piezoelectric vibrator 12, an acoustic vortex effect is generated in the non-shaped tube as shown in FIG. Figure 5 As shown in Figure 2, the acoustic vortex induces the solution flow into an unstable state, further destroying the laminar structure of the solution and increasing the contact area of ​​the solution.

Claims

1. An on-chip enhanced mixing device using reciprocating flow and acoustic flow, characterized in that: The on-chip enhanced mixing device using reciprocating flow and acoustic flow comprises a plurality of liquid inflow channels, a T-shaped channel, an acoustic vortex mixing enhancement channel, two piezoelectric vibrators and a mixed liquid outlet; The liquid inlet channel comprises a liquid inlet, an inlet channel, a driving chamber and an elastic membrane; the driving chamber and the liquid inlet are top opening structures, and the elastic membrane covers the top opening of the driving chamber; One end of the driving chamber is connected to the liquid inlet through the inlet channel, and the other end is connected to the T-shaped channel; The T-shaped channel comprises a transverse channel and a vertical channel, and a plurality of interfaces are symmetrically arranged on the transverse channel for communicating with the driving chamber of each group of liquid inflow channels; The mixed liquid outlet is a top opening structure; The acoustic vortex mixing and strengthening channel is a symmetrical "non"-shaped structure, with a straight main channel in the middle and symmetrical side channels on both sides, and the main channel and the side channels are 90 degrees; the inlet end of the acoustic vortex mixing and strengthening channel is connected to the tail end of the vertical channel of the T-shaped channel, and the outlet end is connected to the mixed liquid outlet; The piezoelectric vibrators are symmetrically bonded on both sides of the acoustic vortex mixing and strengthening channel.

2. The on-chip enhanced mixing device using reciprocating flow and acoustic flow according to claim 1, characterized in that: The multiple groups of liquid inflow channels are symmetrically arranged, and the number of the groups is determined by the number of liquids to be mixed.

3. An on-chip enhanced mixing device using reciprocating flow and acoustic flow according to claim 1 or 2, characterized in that: The liquid inlet, the inlet channel, the driving chamber, the T-shaped channel, the acoustic vortex mixing and strengthening channel and the mixed liquid outlet are located on the same horizontal plane.

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