A microfluidic device driven by tip discharge

Abstract

The present invention provides a microfluidic device driven by tip discharge, belonging to the technical field of microfluidic control. It includes a tip group module, and the tip group module includes: multiple tips, which are fixedly arranged evenly and equidistantly around a circle; a DC high-voltage power supply, electrically connected to the tip group module; an ITO conductive glass, arranged below the tip group module. By energizing the tip group module, the air near the tips is ionized, and the same charge as the tip surface accumulates on the surface of the droplet, so that it is affected by the electric field force near the tip. Since the tips are fixedly arranged evenly and equidistantly around a circle, the resultant force of the electric field forces received by the droplet is 0. When the tip group module moves, the force balance of the droplet will be broken, and the droplet moves towards the center of the tip group module until it stops at the center of the tip group module again, realizing the driving of the droplet movement by the movement of the tip group module. This device can quickly and accurately control the movement of droplets and can be applied to fields such as microorganisms, medicine, chemistry, and microfluidic control.

Description

Technical Field

[0001] The present invention belongs to the technical field of microfluidic control, and particularly relates to a microfluidic device driven by tip discharge. Background Art

[0002] In the field of nanoscale microfluidics, there are generally two ways to control microfluidics: the first way is to improve the material or microstructure of the droplet-bearing surface, and control the droplet by changing the wettability of the droplet on the bearing surface; the other way is to apply an external force on a bearing surface with appropriate wettability to make the droplet overcome the resistance and thus control the droplet behavior.

[0003] However, the first way usually has defects in terms of flexibility. The droplet can only be transported unidirectionally, and microfabrication or surface treatment must be used, which is costly and has low reliability; most of the second way requires operation on a specially treated surface, and it is impossible to ensure both precision and speed at the same time. When the speed is high, the precision is low, and when the precision is high, the speed is slow.

[0004] However, the existing technology has problems of slow droplet control speed and low control precision. Summary of the Invention

[0005] In order to overcome the above-mentioned deficiencies of the existing technology, the present invention provides a microfluidic device driven by tip discharge.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A microfluidic device driven by tip discharge, comprising:

[0008] A tip group module, the tip group module comprising: a plurality of tips, fixedly arranged uniformly and equidistantly around a circle;

[0009] A DC high-voltage power supply, electrically connected to the tip group module;

[0010] An ITO conductive glass, disposed below the tip group module, and a droplet is provided on the surface of the ITO conductive glass, and the droplet is located at the center of the tip group module.

[0011] Further, an oil layer covers the surface of the ITO conductive glass.

[0012] Further, the distance between the tip group module and the oil layer is 30 mm to 60 mm.

[0013] Further, the voltage adjustment range of the DC high-voltage power supply is 0 - 40 KV.

[0014] Further, it further comprises: a controllable moving platform, which is fixedly connected to the tip group module.

[0015] Further, it further includes: a control module, electrically connected to the controllable mobile platform.

[0016] Further, the positive pole of the DC high-voltage power supply is connected to the tip group module, and the ground wire of the DC high-voltage power supply is connected to the conductive side of the ITO conductive glass.

[0017] A tip discharge-driven microfluidic device provided by the present invention has the following beneficial effects:

[0018] When a high voltage is applied to one end of the tip, an electric field will be generated between the tip and the ITO conductive glass. Due to the effect of the electric field, charges accumulate on the surface of the tip. Ions in the air with the same charge as the tip tip move away from the tip, and ions with the opposite charge to the tip tip approach the tip; at this time, ions with the same charge as the tip surface are injected onto the surface of the droplet, making the surface of the droplet subject to the electric field force; since multiple tips are fixedly arranged around the circle at equal intervals, and the droplet is located at the center of the tip group module, the resultant force of the electric field forces acting on the droplet is 0; when the tip group module moves, the lateral thrust exerted by the electric field of the tip close to the droplet is greater than the thrust in the opposite direction provided by the tip symmetrically arranged away from the droplet, and the force balance of the droplet will be broken, and the droplet will move towards the center of the tip group module until it stops at the center of the tip group module again, thereby realizing the driving of the microfluid to move by the movement of the tip group module.

[0019] The present invention can change the speed and precision of controlling the droplet by controlling the number of tips and the voltage value, and solves the problems of slow droplet control speed and low control precision in the existing problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention and its design, the accompanying drawings required for this embodiment will be briefly introduced below. The accompanying drawings in the following description are only partial embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic structural diagram of a tip discharge-driven microfluidic device according to an embodiment of the present invention;

[0022] Figure 2 It is a schematic structural diagram of the tip group module according to an embodiment of the present invention;

[0023] Figure 3 It is a schematic diagram of the tip discharge principle according to an embodiment of the present invention;

[0024] Figure 4 It is a schematic diagram of controlling the movement of the droplet by applying this device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To enable those skilled in the art to better understand the technical solution of the present invention and be able to implement it, the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the technical solution of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0027] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly specified or limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more, which will not be elaborated here.

[0028] Embodiment:

[0029] The present invention provides a microfluidic device driven by tip discharge, specifically as Figure 1 shown, including:

[0030] A tip group module 4, the tip group module 4 includes: a plurality of tips, which are fixedly arranged evenly and equidistantly around a circle; a DC high-voltage power supply 1, which is electrically connected to the tip group module 4; an ITO conductive glass 6, which is arranged below the tip group module 4, and a droplet is provided on the surface of the ITO conductive glass 6, and the droplet is located at the center of the tip group module 4.

[0031] Specifically, the positive electrode of the DC high-voltage power supply 1 is connected to the tip group module 4, and the ground wire is connected to the conductive side of the ITO conductive glass 6.

[0032] The principle of controlling the movement of the droplet in this embodiment is:

[0033] When a high voltage is applied to one end of the needle tip, an electric field will be generated between the needle tip and the ITO conductive glass 6. Due to the effect of the electric field, charges accumulate on the surface of the needle tip. Ions in the air with the same charge as the tip of the needle move away from the needle tip, and ions with the opposite charge to the tip of the needle approach the needle tip. At this time, ions with the same charge as the surface charge of the needle tip are injected into the surface of the droplet, causing the surface of the droplet to be affected by the electric field force. Since multiple needle tips are fixedly arranged around a circle at equal distances, and the droplet is located at the center of the needle tip group module 4, the resultant electric field force acting on the droplet is 0. When the needle tip group module 4 moves, the lateral thrust exerted by the electric field of the needle tip close to the droplet is greater than the thrust in the opposite direction provided by the needle tip symmetrically arranged away from the droplet. The force balance of the droplet will be broken, and the droplet will move towards the center of the needle tip group module 4 until it comes to rest again at the center of the needle tip group module, thereby realizing the driving of microfluid movement by the movement of the needle tip group module.

[0034] This device can be used in various chemical and biological applications, such as blood testing, and can provide higher flexibility, less sample consumption, and reduced equipment manufacturing costs.

[0035] Specifically, it also includes: the ITO conductive glass 6, which is arranged below the needle tip group module 4.

[0036] Specifically, the surface of the ITO conductive glass 6 is covered with an oil layer. Through the corona discharge of the needle tips of the needle tip group module, ions and electrons are ionized and generated in the ionization region near the emitter. Under the action of the electric field, the ions move towards the collecting electrode in the migration region, and a strong ion distribution is formed within a circular range on the surface of the collector. When these ions are injected into the oil layer, the electric field will drive the oil layer to move out of the ion distribution region. At this time, the oil layer in the overlapping ion distribution region of the multi-needle corona discharge is simultaneously subjected to the driving forces generated by the discharges of multiple needle tips, thereby forming the deposition of the oil layer. At this time, the oil layer wraps the water droplet and drives the water droplet to move along with the deposition region of the oil layer.

[0037] In addition, the oil layer can also reduce the movement resistance of the droplet, cover the surface of the droplet with an oil layer, increase the surface charge density of the droplet, and better drive the movement of the droplet.

[0038] Specifically, the distance between the needle tip group module 4 and the oil layer is 30 mm to 60 mm.

[0039] Specifically, the voltage regulation range of the DC high voltage power supply is 0 - 40 KV.

[0040] Specifically, it also includes: the controllable moving platform 3, which is fixedly connected to the needle tip group module 4.

[0041] Specifically, it also includes: the control module, which is electrically connected to the controllable moving platform 3.

[0042] The following embodiments are the specific operation procedures for applying this device to control the movement of the droplet:

[0043] Operation step 1: Prepare an ITO conductive glass 6 and apply an oil layer on its surface.

[0044] Operation step 2: Set the distance between the tip group module 4 and the oil layer on the surface of the ITO conductive glass 6 to 30 - 60 mm, and the angle to 80 - 110°.

[0045] Operation step 3: Connect the DC high - voltage terminal of the DC power supply to the tip end, and the ground terminal to the ITO conductive glass module.

[0046] Operation step 4: Drop a small water droplet 7 on the surface of the oil layer.

[0047] Operation step 5: Turn on the DC voltage and adjust the voltage to 12 kV.

[0048] Control the movement of the controllable moving platform through the operation control module 2, and the droplet aligned by the tip moves accordingly.

[0049] The above - described embodiments are only the preferred specific embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Any simple changes or equivalent replacements of the technical solutions that can be obviously obtained by those skilled in the art within the technical scope disclosed by the present invention all belong to the protection scope of the present invention.

Claims

1. A microfluidic device driven by tip discharge, characterized in that, it includes: a tip group module (4), the tip group module (4) includes: multiple tips, which are fixedly arranged evenly and equidistantly around a circle; it further includes: a controllable moving platform (3), the controllable moving platform (3) is fixedly connected to the tip group module (4); a DC high-voltage power supply (1), which is electrically connected to the tip group module (4); an ITO conductive glass (6), which is arranged below the tip group module (4), there is a droplet on the surface of the ITO conductive glass (6), and the droplet is located at the center of the tip group module (4); an oil layer covers the surface of the ITO conductive glass (6); Through the corona discharge of the tips of the tip group module (4), ions and electrons are ionized and generated in the ionization region near the emitter. Under the action of the electric field, the ions move towards the ITO conductive glass (6) in the migration region, and an ion distribution is formed within a circular range on the surface of the ITO conductive glass (6); when these ions are injected into the oil layer, the electric field will drive the oil layer to move out of the ion distribution region; at this time, the oil layer in the ion distribution region where the multi-tip corona discharges overlap is simultaneously subjected to the driving forces generated by the discharges of multiple tips, thereby forming the deposition of the oil layer; at this time, the oil layer wraps the water droplet, driving the water droplet to move along with the deposition region of the oil layer; When a high voltage is applied to one end of the tip, an electric field will be generated between the tip and the ITO conductive glass (6). Due to the action of the electric field, charges accumulate on the surface of the tip, and the ions in the air with the same charge as the tip tip move away from the tip, and the ions with the opposite charge to the tip tip approach the tip; at this time, ions with the same charge as the tip surface are injected into the surface of the droplet, causing the surface of the droplet to be subjected to the action of the electric field force; since multiple tips are fixedly arranged evenly and equidistantly around a circle and the droplet is located at the center of the tip group module (4), the resultant force of the electric field forces on the droplet is 0; when the tip group module (4) moves, the force balance of the droplet will be broken, and the droplet moves towards the center of the tip group module (4) until it stops at the center of the tip group module again, thereby realizing the driving of the microfluid by the movement of the tip group module.

2. A microfluidic device driven by tip discharge according to claim 1, characterized in that, the distance between the tip group module (4) and the oil layer is 30 mm to 60 mm.

3. A microfluidic device driven by tip discharge according to claim 1, characterized in that, the voltage adjustment range of the DC high-voltage power supply (1) is 0 - 40 KV.

4. A microfluidic device driven by tip discharge according to claim 1, characterized in that, it further includes: a control module, which is electrically connected to the controllable moving platform (3).

5. A microfluidic device driven by tip discharge according to claim 1, characterized in that, the positive pole of the DC high-voltage power supply (1) is connected to the tip group module (4), and the ground wire of the DC high-voltage power supply (1) is connected to the conductive side of the ITO conductive glass (6).

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