A multi-droplet manipulation device based on surface acoustic waves

Abstract

The invention discloses a multi-droplet operation device based on surface acoustic wave, comprising a lithium niobate substrate, N interdigital electrodes, an operation panel, a vibration-absorbing glue and a control module; the operation panel is arranged at the center of the lithium niobate substrate, and the N interdigital electrodes are evenly arranged around the operation panel; a planned path for droplet driving and droplet reaction is provided on the operation panel; the control module is electrically connected to the N interdigital electrodes, and is used to control the N interdigital electrodes to emit corresponding surface acoustic waves to drive the droplets on the operation panel to move on the planned path. The invention can realize precise driving, merging, and splitting of multiple droplets, and the operation panel can be replaced, which is economical.

Description

Technical Field

[0001] The invention relates to the technical field of micro-droplet operation, and in particular to a multi-droplet operation device based on surface acoustic waves. Background Art

[0002] Traditional biological detection and biological reactions are carried out in test tubes, which have disadvantages such as long mixing reaction time, poor mixing uniformity, and difficulty in removing bubbles. The droplets have a large specific surface area, and the reaction between droplets is rapid, and it is also easier to improve the uniformity of the composition. Reacting on a two-dimensional operating plate platform can easily remove bubbles in the droplets, stir the droplets to make the composition uniform, and remove the droplets by adsorption.

[0003] Electric or magnetic field driven droplets require that the droplets have charge or magnetism, which greatly restricts the application of two-dimensional micro-reaction platforms. Surface acoustic waves are elastic waves that do not require droplets to have charge or magnetism, and have advantages in droplet driving. At present, droplets driven on solid surfaces using surface acoustic waves have disadvantages such as difficulty in driving droplets to move precisely and difficulty in driving multiple droplets to react sequentially. Based on the surface acoustic wave interdigital transducer array, the free movement of droplets on the surface of fluorinated oil can be achieved by using acoustic streaming, but there is a problem that the droplets are difficult to extract from the fluorinated oil after the reaction and the chemical properties of the fluorinated oil itself limit biological experiments. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a multi-droplet operation device based on surface acoustic waves to address the defects involved in the background technology, so as to achieve precise driving, merging and splitting of multiple droplets. In addition, the operation panel is pasted on the substrate and can be replaced, which has good economic efficiency and can be applied on a large scale.

[0005] The present invention adopts the following technical solutions to solve the above technical problems:

[0006] A multi-droplet operation device based on surface acoustic waves, comprising a lithium niobate substrate, N interdigital electrodes, an operation panel, a vibration absorbing glue and a control module, wherein N is a natural number greater than or equal to 3;

[0007] The N interdigital electrodes and the operating plate are both arranged on the lithium niobate substrate, wherein the operating plate is arranged at the center of the lithium niobate substrate, and the N interdigital electrodes are evenly arranged around the operating plate;

[0008] The operation panel is provided with a planned path for droplet driving and droplet reaction; the planned path includes a plurality of stationary points and a plurality of connection grooves for connecting the stationary points, wherein the stationary points are ridge-shaped microstructures forming a wetting gradient for adsorbing droplets;

[0009] The control modules are electrically connected to the N interdigital electrodes respectively, and are used to control the N interdigital electrodes to emit corresponding surface acoustic waves to drive the droplets on the operation board to move on the planned path, thereby realizing the driving, merging, and splitting of multiple droplets;

[0010] The vibration absorbing glue is arranged on the lithium niobate substrate to form a closed loop including the lithium niobate substrate and N interdigital electrodes, and is used for absorbing overflowing surface acoustic waves.

[0011] As a further optimization scheme of the multi-droplet operation device based on surface acoustic waves of the present invention, it also includes N reflection gratings, which are arranged one by one on the outside of the N interdigitated electrodes and are all located in the closed loop formed by the vibration-absorbing glue, so as to enhance the driving force of the surface acoustic wave on the liquid on the operation plate.

[0012] As a further optimization scheme of a multi-droplet operation device based on surface acoustic waves of the present invention, the control module includes a signal source and a power amplifier. The signal source is used to generate a sinusoidal signal. After being amplified by the power amplifier, the signal acts on the interdigital transducer to generate surface acoustic waves.

[0013] As a further optimization solution of the multi-droplet operation device based on surface acoustic waves of the present invention, the operation plate is attached to the lithium niobate substrate by glue.

[0014] As a further optimization scheme of the multi-droplet operation device based on surface acoustic waves of the present invention, N is 4, and the thickness range of the interdigital electrodes is 100-200 nm.

[0015] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0016] 1. The present invention realizes precise driving of droplets, and droplets within a certain size span can be precisely positioned; only specific stationary points in different vertical rows are connected through the wetting gradient, so that multiple droplets can be driven in an orderly manner; when droplets pass through specific microstructures, the droplets are split under the combined action of the wetting gradient, capillary effect, and surface acoustic wave;

[0017] 2. The operation panel is pasted on the lithium niobate substrate and can be torn off and replaced, greatly reducing maintenance costs; the operation panel is a two-dimensional platform with the advantages of strong operability and easy integration with other equipment;

[0018] 3. The present invention has a simple and portable structure and strong operability. It can realize non-contact precise driving of multiple droplets and the merging and splitting of droplets. It has low sample loss and short reaction time and can be applied to a variety of biochemical micro-droplet operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a schematic diagram of the structure of the present invention;

[0020] Figure 2 is a schematic diagram of the electric field between the motors in the interdigitated electrodes of the present invention;

[0021] Figure 3 It is a structural schematic diagram of the operating panel in the present invention.

[0022] In the figure, 1-operating panel, 2-interdigitated electrodes, 3-reflection grid, 4-lithium niobate substrate, 5-vibration absorbing glue. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings:

[0024] The present invention can be implemented in many different forms and should not be considered to be limited to the embodiments described herein. On the contrary, these embodiments are provided to make this disclosure thorough and complete, and will fully express the scope of the present invention to those skilled in the art. In the accompanying drawings, components are enlarged for clarity.

[0025] like Figure 1 As shown, the present invention discloses a multi-droplet operation device based on surface acoustic waves, comprising a lithium niobate substrate, N interdigital electrodes, an operation panel, a vibration absorbing glue and a control module, where N is a natural number greater than or equal to 3;

[0026] The N interdigital electrodes and the operating plate are both arranged on the lithium niobate substrate, wherein the operating plate is arranged at the center of the lithium niobate substrate, and the N interdigital electrodes are evenly arranged around the operating plate; Figure 2 As shown, an alternating electric field is generated between the electrodes of the interdigitated electrodes, and surface acoustic waves are excited on the surface of the lithium niobate wafer according to the inverse piezoelectric effect;

[0027] like Figure 3 As shown, the operation board is provided with a planned path for droplet driving and droplet reaction; the planned path includes a plurality of stationary points and a plurality of connection grooves for connecting the stationary points, wherein the stationary points are ridge-shaped microstructures forming a wetting gradient for adsorbing droplets;

[0028] The control modules are electrically connected to the N interdigital electrodes respectively, and are used to control the N interdigital electrodes to emit corresponding surface acoustic waves to drive the droplets on the operation board to move on the planned path, thereby realizing the driving, merging, and splitting of multiple droplets;

[0029] The vibration absorbing glue is arranged on the lithium niobate substrate to form a closed loop including the lithium niobate substrate and N interdigital electrodes, and is used for absorbing overflowing surface acoustic waves.

[0030] The present invention may also include N reflection gratings, which are arranged one by one on the outside of the N interdigitated electrodes and are all located in a closed loop formed by the vibration absorbing glue to enhance the driving force of the surface acoustic wave on the liquid on the operating panel.

[0031] The control module comprises a signal source and a power amplifier. The signal source is used to generate a sinusoidal signal. After being amplified by the power amplifier, the signal acts on the interdigital transducer to generate a surface acoustic wave.

[0032] The operating plate is glued to the lithium niobate substrate, N is preferably 4, and the thickness of the interdigital electrodes is in the range of 100-200 nm.

[0033] The surface acoustic waves excited by the interdigital transducer can be coupled into standing waves and traveling waves on the operating panel. The coupled standing waves can change the wetting properties of the droplets and promote the formation of microflows inside the droplets. The microflows make the internal components of the droplets evenly mixed; the traveling waves drive the droplets to move between the stagnation points. Because the wetting gradient at the center of the stagnation point is the lowest, the droplets always move from the center of one stagnation point to the center of another stagnation point, realizing precise control of the droplet position. When multiple droplets are located in the same vertical row of stagnation points, the traveling waves are absorbed by the droplets closest to the wave propagation direction, while other droplets in the vertical row can hardly absorb the traveling waves. Therefore, the droplets closest to the wave propagation direction are driven into the stagnation points of other droplets in the vertical row, and the droplets merge under the joint action of the surface waves and the wetting gradient. The wetting gradients at different horizontal positions in different vertical rows are different, and the liquid can only enter the stagnation points of different vertical rows at specific positions. When the droplets pass through a specific microstructure, the droplets split under the joint action of the wetting gradient, capillary effect, and surface acoustic waves.

[0034] The present invention divides the surface into stationary points through the wetting gradient, thereby achieving precise driving of droplets, and droplets within a certain size span can be precisely positioned. Only specific stationary points in different vertical rows are connected through the wetting gradient, thereby achieving orderly driving of multiple droplets. When droplets pass through specific microstructures, the droplets are split under the combined action of the wetting gradient, capillary effect, and surface acoustic wave. At the same time, the operating panel is pasted on the lithium niobate substrate and can be torn off and replaced, greatly reducing maintenance costs. The operating panel is a two-dimensional platform with the advantages of strong operability and easy integration with other equipment. The present invention has a simple and portable structure and strong operability, and can achieve non-contact precise driving of multiple droplets and the merging and splitting of droplets. It has low sample loss and short reaction time, and can be applied to a variety of biochemical micro-droplet operations.

[0035] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0036] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-droplet operation device based on surface acoustic waves, characterized in that: It includes a lithium niobate substrate, N interdigital electrodes, an operation panel, a vibration absorbing adhesive and a control module, where N is a natural number greater than or equal to 3; The N interdigital electrodes and the operating plate are both arranged on the lithium niobate substrate, wherein the operating plate is arranged at the center of the lithium niobate substrate, and the N interdigital electrodes are evenly arranged around the operating plate; The operation panel is provided with a planned path for droplet driving and droplet reaction; the planned path includes a plurality of stationary points and a plurality of connection grooves for connecting the stationary points, wherein the stationary points are ridge-shaped microstructures for forming a wetting gradient, and the wetting gradient at the center of the stationary point is the lowest, which is used for adsorbing droplets; The control modules are electrically connected to the N interdigital electrodes respectively, and are used to control the N interdigital electrodes to emit corresponding surface acoustic waves to drive the droplets on the operation board to move on the planned path, thereby realizing the driving, merging, and splitting of multiple droplets; The vibration absorbing glue is arranged on the lithium niobate substrate to form a closed loop including the lithium niobate substrate and N interdigital electrodes, and is used for absorbing overflowing surface acoustic waves.

2. The multi-droplet operation device based on surface acoustic waves according to claim 1, characterized in that: It also comprises N reflection gratings, which are arranged one by one on the outside of the N interdigital electrodes and are all located in a closed loop formed by the vibration absorbing glue, so as to strengthen the driving force of the surface acoustic wave on the liquid on the operating panel.

3. The multi-droplet operation device based on surface acoustic waves according to claim 1, characterized in that: The control module comprises a signal source and a power amplifier. The signal source is used to generate a sinusoidal signal. After being amplified by the power amplifier, the signal acts on the interdigital transducer to generate a surface acoustic wave.

4. The multi-droplet operation device based on surface acoustic waves according to claim 1, characterized in that: The operating panel is adhered to the lithium niobate substrate by glue.

5. The multi-droplet operation device based on surface acoustic waves according to claim 1, characterized in that: When N is 4, the thickness of the interdigitated electrode is in the range of 100-200 nm.

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