CN115672227B

CN115672227B - Multi-liquid drop operation device based on surface acoustic wave

Info

Publication number: CN115672227B
Application number: CN202211343734.0A
Authority: CN
Inventors: 张耀东; 杨颖�
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2022-10-31
Filing date: 2022-10-31
Publication date: 2025-02-21
Anticipated expiration: 2042-10-31
Also published as: CN115672227A

Abstract

The invention discloses a multi-liquid drop operation device based on a surface acoustic wave, which comprises a lithium niobate substrate, N interdigital electrodes, an operation board, vibration absorbing glue and a control module, wherein the operation board is arranged at the center of the lithium niobate substrate, the N interdigital electrodes are uniformly arranged around the periphery of the operation board, a planning path for driving liquid drops and reacting the liquid drops is arranged on the operation board, and the control module is electrically connected with the N interdigital electrodes and is used for controlling the N interdigital electrodes to send out corresponding liquid drops on the surface acoustic wave driving operation board to move on the planning path. The invention can realize accurate driving, merging and splitting control of multiple liquid drops, and the operation panel can be replaced, thereby having good economy.

Description

Multi-liquid drop operation device based on surface acoustic wave

Technical Field

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

Background

The traditional biological detection and biological reaction are carried out in a test tube, and the defects of long mixing reaction time, high mixing uniformity, difficult bubble discharge and the like exist. The specific surface area of the liquid drops is large, the reaction between the liquid drops is rapid, and the uniformity of the components is easier to improve. The reaction is carried out on a two-dimensional operation panel platform, so that bubbles in liquid drops can be easily removed, and the liquid drops are stirred to ensure that components are uniform and the liquid drops are removed by adsorption.

The electric field or the magnetic field drives the liquid drop, so that the liquid drop is required to have charges or magnetism, and the application of the two-dimensional micro-reaction platform is greatly restricted. The surface acoustic wave is an elastic wave, has no charge or magnetism requirement on liquid drops, and has advantages in the aspect of liquid drop driving. At present, the liquid drops driven on the solid surface by utilizing the surface acoustic wave have the defects of difficult driving of the liquid drops to accurately move, difficult driving of a plurality of liquid drops to react sequentially and the like. The interdigital transducer array based on the surface acoustic wave can realize the free movement of liquid drops on the surface of the fluorinated oil by utilizing the action of acoustic flow, but has the problems that the liquid drops are difficult to extract from the fluorinated oil after reaction and the limitation of the chemical properties of the fluorinated oil to biological experiments.

Disclosure of Invention

Aiming at the defects related to the background technology, the invention provides the multi-drop operation device based on the surface acoustic wave, which realizes precise driving, merging and splitting of the multi-drops, and the operation board is stuck on the substrate, can be replaced, has good economy and can realize large-scale application.

The invention adopts the following technical scheme for solving the technical problems:

A multi-drop operation device based on surface acoustic wave comprises a lithium niobate substrate, N interdigital electrodes, an operation board, vibration absorbing glue and a control module, wherein N is a natural number greater than or equal to 3;

the N interdigital electrodes and the operation plate are arranged on the lithium niobate substrate, wherein the operation plate is arranged at the center of the lithium niobate substrate, and the N interdigital electrodes are uniformly arranged around the periphery of the operation plate;

The operation board is provided with a planning path for driving liquid drops and reacting liquid drops, wherein the planning path comprises a plurality of residence points and a plurality of connecting grooves for communicating the residence points, and the residence points are ridge microstructures for forming infiltration gradients and are used for adsorbing the liquid drops;

the control module is respectively and electrically connected with the N interdigital electrodes and is used for controlling the N interdigital electrodes to send out corresponding liquid drops on the surface acoustic wave driving operation board to move on a planned path so as to realize driving, merging and splitting of multiple liquid drops;

The vibration absorbing glue is arranged on the lithium niobate substrate to form a closed loop containing the lithium niobate substrate and N interdigital electrodes and is used for absorbing overflowed surface acoustic waves.

As a further optimization scheme of the multi-drop operation device based on the surface acoustic wave, the multi-drop operation device based on the surface acoustic wave further comprises N reflection grids, wherein the N reflection grids are arranged on the outer sides of the N interdigital electrodes in a one-to-one correspondence mode and are all positioned in a closed loop formed by the vibration absorbing glue and used for enhancing the driving force of the surface acoustic wave on liquid on an operation plate.

As a further optimization scheme of the multi-drop operation device based on the surface acoustic wave, the control module comprises a signal source and a power amplifier, wherein the signal source is used for generating a sine signal, and the signal acts on the interdigital transducer to generate the surface acoustic wave after being amplified by the power amplifier.

As a further optimization scheme of the multi-drop operation device based on the surface acoustic wave, the operation plate is adhered to the lithium niobate substrate through glue.

As a further optimization scheme of the multi-drop operation device based on the surface acoustic wave, N is 4, and the thickness range of the interdigital electrode is 100-200 nm.

Compared with the prior art, the technical scheme provided by the invention has the following technical effects:

1. The invention realizes the accurate driving of the liquid drops, and simultaneously the liquid drops in a certain size span range can be accurately positioned, and only specific resident points of different longitudinal rows are communicated through the infiltration gradient to realize the orderly driving of a plurality of liquid drops;

2. the operation board is a two-dimensional platform, and has the advantages of strong operability, easiness in integrating other equipment and the like;

3. The invention has simple and portable structure and strong operability, can realize non-contact accurate driving of multiple liquid drops and merging and splitting of the liquid drops, has little loss on samples and short reaction time, and can be applied to the operation of multiple biochemical micro liquid drops.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic diagram of the electric field between motors in the interdigitated electrodes of the present invention;

Fig. 3 is a schematic structural view of an operation panel in the present invention.

In the figure, a 1-operation plate, a 2-interdigital electrode, a 3-reflecting grating, a 4-lithium niobate substrate and 5-vibration absorbing glue.

Detailed Description

The technical scheme of the invention is further described in detail below with reference to the accompanying drawings:

This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the components are exaggerated for clarity.

As shown in fig. 1, the invention discloses a multi-drop operation device based on surface acoustic waves, which comprises a lithium niobate substrate, N interdigital electrodes, an operation board, vibration absorbing glue and a control module, wherein N is a natural number greater than or equal to 3;

The N interdigital electrodes and the operation plate are arranged on the lithium niobate substrate, wherein the operation plate is arranged at the center of the lithium niobate substrate, and the N interdigital electrodes are uniformly arranged around the circumference of the operation plate;

The invention can also comprise N reflecting grids which are arranged at the outer sides of the N interdigital electrodes in a one-to-one correspondence manner and are all positioned in a closed loop formed by the vibration absorbing glue for enhancing the driving force of the surface acoustic wave on the liquid on the operation plate.

The control module comprises a signal source and a power amplifier, wherein the signal source is used for generating a sine signal, and the signal is amplified by the power amplifier and then acts on the interdigital transducer to generate the surface acoustic wave.

The operation plate is stuck on the lithium niobate substrate through glue, N is preferably 4, and the thickness of the interdigital electrode is in the range of 100-200 nm.

The acoustic surface wave excited by the interdigital transducer can be coupled into standing waves and travelling waves on the operation board, the standing waves which are coupled can change the infiltration performance of liquid drops and promote the interior of the liquid drops to form micro-flow, the micro-flow enables the components in the liquid drops to be uniformly mixed, the travelling waves drive the liquid drops to move between the standing points, and the liquid drops always move from the center of one standing point to the center of the other standing point because of the lowest infiltration gradient of the center of the standing point, so that the accurate control of the positions of the liquid drops is realized. When a plurality of liquid drops are positioned in the standing point of the same longitudinal row, the travelling wave is absorbed by the liquid drop closest to the wave propagation direction, and the travelling wave is hardly absorbed by other liquid drops in the longitudinal row, so that the liquid drop closest to the wave propagation direction is driven into the standing point of the other liquid drops in the longitudinal row, and the liquid drops are combined under the combined action of the surface wave and the infiltration gradient. The wetting gradients of different longitudinal rows at different horizontal positions are different, and liquid can only enter the standing points of different longitudinal rows at specific positions. When the liquid drops pass through the specific microstructure, the division of the liquid drops is realized under the combined action of the wetting ladder, the capillary effect and the surface acoustic wave.

The invention divides the surface into the standing points through the infiltration gradient, realizes the accurate driving of the liquid drops, and simultaneously can accurately position the liquid drops within a certain size span range. And only specific resident points of different longitudinal rows are communicated through the infiltration gradient, so that orderly driving of multiple liquid drops is realized. When the liquid drop passes through a specific microstructure, the division of the liquid drop is realized under the combined action of an infiltration gradient, a capillary effect and a surface acoustic wave. Meanwhile, the operation plate is stuck on the lithium niobate substrate and can be torn off for replacement, so that the maintenance cost is greatly reduced. The operation panel is a two-dimensional platform, and has the advantages of strong operability, easiness in integrating other devices and the like. The invention has simple and portable structure and strong operability, and can realize non-contact accurate driving of multiple liquid drops and merging and splitting of the liquid drops. The method has the advantages of less loss on the sample and short reaction time, and can be applied to various biochemical micro-droplet operations.

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 commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

While the foregoing is directed to embodiments of the present invention, other and further details of the invention may be had by the present invention, it should be understood that the foregoing description is merely illustrative of the present invention and that no limitations are intended to the scope of the invention, except insofar as modifications, equivalents, improvements or modifications are within the spirit and principles of the invention.

Claims

1. A multi-droplet operation device based on surface acoustic waves, characterized in that it comprises 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;

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 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 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. According to the multi-droplet operation device based on surface acoustic waves according to claim 1, it is characterized in that 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 a 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.

3. According to the multi-droplet operation device based on surface acoustic waves as described in claim 1, it is characterized in that the control module includes a signal source and a power amplifier, the signal source is used to generate a sinusoidal signal, and the signal is amplified by the power amplifier and acts on the interdigital transducer to generate surface acoustic waves.

4 . The multi-droplet operation device based on surface acoustic waves according to claim 1 , wherein the operation plate is glued to the lithium niobate substrate.

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