阅读说明：本技术 一种制造图案化表面电荷的方法和疏水绝缘薄膜及其应用 (Method for manufacturing patterned surface charge, hydrophobic insulating film and application thereof ) 是由 周国富 吴昊 弗里德里希·穆盖莱 于 2019-09-17 设计创作，主要内容包括：本发明公开了一种制造图案化表面电荷的方法和疏水绝缘薄膜及其应用,该制造图案化表面电荷的方法包括先在下基板上设置下电极层,并在下电极层上背离下基板的表面设置疏水绝缘层,而后在疏水绝缘层上背离下电极层的表面设置导电液滴,在导电液滴上设置与导电液滴接触的上电极,再向上电极和下电极层之间施加电压,停止电压后去除导电液滴。通过以上方式,本发明制造图案化表面电荷的方法利用一个外加电源,可通过控制导电液滴的分布设置和改变导电液滴的大小等方法即可获得图案化的表面电荷,且通过改变施加电压的大小或施加电压的时间,可调节材料表面束缚电荷的电荷密度；该方法方便快捷,简单易行,施加较小电压即可实现,且生产成本低。(The invention discloses a method for manufacturing patterned surface charges, a hydrophobic insulating film and application thereof. In this way, the method for manufacturing patterned surface charges of the present invention utilizes an external power source, can obtain patterned surface charges by controlling the distribution of the conductive droplets and changing the size of the conductive droplets, and can adjust the charge density of the bound charges on the surface of the material by changing the magnitude of the applied voltage or the time of the applied voltage; the method is convenient, rapid, simple and easy to implement, can be realized by applying smaller voltage, and has low production cost.)

1. A method of fabricating a patterned surface charge, comprising the steps of:

s1, arranging a lower electrode layer on the lower substrate; then, a hydrophobic insulating layer is arranged on the surface, deviating from the lower substrate, of the lower electrode layer;

s2, arranging conductive liquid drops on the surface, facing away from the lower electrode layer, of the hydrophobic insulating layer;

s3, arranging an upper electrode on the conductive liquid drop, wherein the upper electrode is in contact with the conductive liquid drop;

s4, applying voltage between the upper electrode and the lower electrode layer;

and S5, removing the conductive liquid drop after the voltage is removed.

2. The method of manufacturing a patterned surface charge according to claim 1, wherein in step S3, the upper electrode is an electrode rod inserted in the conductive droplet; in step S4, the lower electrode layer is grounded, and a voltage is applied to the upper electrode.

3. The method of claim 1, wherein in step S3, the upper electrode is an upper electrode layer disposed on an upper substrate;

step S2 specifically includes: arranging spacing support members on the hydrophobic insulating layer, and then arranging conductive liquid drops on the hydrophobic insulating layer in the areas where the spacing support members are not arranged;

step S3 specifically includes: and arranging an upper electrode layer on the upper substrate, and then arranging the upper substrate on the interval support, wherein the upper electrode layer on the upper substrate faces the conductive liquid drop and is in contact with the conductive liquid drop.

4. The method of fabricating a patterned surface charge according to claim 1, wherein the conductive liquid droplet is ultrapure water, an aqueous solution, an ionic liquid, or a liquid metal.

5. The method of claim 1, wherein the material of the hydrophobic insulating layer comprises at least one of PTFE, Teflon AF, Cytop, Hyflon, PDMS.

6. The method of claim 5, wherein the hydrophobic insulating layer has a thickness of 10nm to 5 mm.

7. The method for manufacturing a patterned surface charge according to claim 1, wherein the step S1 specifically comprises: and arranging a lower electrode layer on the lower substrate, arranging an insulating layer on the surface of the lower electrode layer, which is far away from the lower substrate, and arranging a hydrophobic insulating layer on the surface of the insulating layer, which is far away from the lower electrode layer.

8. The method of claim 7, wherein the insulating layer is made of a silicon-based dielectric material, a fluoropolymer, or Parylene.

9. A hydrophobic insulating film having a patterned surface charge, which is obtained by the method for producing a patterned surface charge according to any one of claims 1 to 8.

10. Use of the hydrophobic insulating film with patterned surface charge of claim 9 in the manufacture of a microfluidic device, a nanofluidic device, or a micro-nano electronic device.

Technical Field

The invention relates to the technical field of material preparation, in particular to a method for manufacturing patterned surface charges, a hydrophobic insulating film and application thereof.

Background

The existence of surface charges plays an important role in the fields of hydrophobic insulating materials, such as micro-nano fluid, micro-nano electron, biomolecule surface adsorption, micro-nano self-assembly, new energy acquisition and the like. It is of great importance to produce surface bound charges that have a specific pattern and that can be present stably on the surface of hydrophobic insulation materials, especially in humid or some extreme environments. The current method for producing patterned surface charges is a method of electron beam irradiation, but the method requires the use of high voltage of over kilovolts, and has complicated process, high equipment cost and high production cost.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a method of fabricating a patterned surface charge and a hydrophobic insulating film and applications thereof.

The technical scheme adopted by the invention is as follows: a method of fabricating a patterned surface charge, comprising the steps of:

s1, arranging a lower electrode layer on the lower substrate; then, a hydrophobic insulating layer is arranged on the surface, deviating from the lower substrate, of the lower electrode layer;

s2, arranging conductive liquid drops on the surface, facing away from the lower electrode layer, of the hydrophobic insulating layer;

s3, arranging an upper electrode on the conductive liquid drop, wherein the upper electrode is in contact with the conductive liquid drop;

s4, applying voltage between the upper electrode and the lower electrode layer;

and S5, removing the conductive liquid drop after the voltage is removed.

In step S3, a voltage is applied between the upper electrode and the lower electrode, a bound charge is generated at a position on the surface of the hydrophobic insulating layer corresponding to the three-phase line of the conductive liquid droplet, and during the application of the voltage, a contact angle between the conductive liquid droplet and the hydrophobic insulating layer changes, and the three-phase line of the conductive liquid droplet moves, so as to form a patterned surface charge on the surface of the hydrophobic insulating layer. Generally, the greater the applied voltage in step S4, the greater the density of the surface bound charges generated, but the applied voltage generally does not exceed the voltage that the hydrophobic insulating layer can withstand, and can be generally-30V, -60V, -80V, -90V, -120V, etc.

In the manufacturing process, conductive liquid drops can be arranged on the surface of the hydrophobic insulating layer, which is far away from the lower electrode layer, according to a required surface charge target pattern, and then voltage is applied to the conductive liquid drops through the upper electrode layer and the lower electrode layer one by one or simultaneously by utilizing an external power supply so as to prepare patterned surface charge; alternatively, the surface charge pattern may be manufactured by disposing one or more conductive droplets and correspondingly manufacturing the surface charge pattern, and then repeating the disposing of the conductive droplets and the manufacturing of the surface charge pattern to complete the manufacturing of the target surface charge pattern in several times.

Preferably, in step S3, the upper electrode is an electrode rod inserted into the conductive liquid droplet; in step S4, the lower electrode layer is grounded, and a voltage is applied to the upper electrode. The electrode rod may be in various shapes such as a cylinder, a rectangular parallelepiped, a cone, etc.; the surface of the electrode rod may be smooth or rough.

Preferably, in step S3, the upper electrode is an upper electrode layer disposed on the upper substrate; step S2 specifically includes: arranging spacing support members on the hydrophobic insulating layer, and then arranging conductive liquid drops on the hydrophobic insulating layer in the areas where the spacing support members are not arranged; step S3 specifically includes: and arranging an upper electrode layer on the upper substrate, and then arranging the upper substrate on the interval support, wherein the upper electrode layer on the upper substrate faces the conductive liquid drop and is in contact with the conductive liquid drop.

The upper substrate and the lower substrate may be rigid or flexible substrates, and may be specifically a glass substrate, a plastic substrate or a metal substrate, and the materials of the upper substrate and the lower substrate may be the same or different. The material of the upper electrode and the lower electrode layer can be metal, two-dimensional conductive material, indium tin oxide or heavily doped semiconductor. The spacer support pad typically has a thickness of 10nm to 5 mm.

Preferably, the conductive liquid droplets are ultrapure water, an aqueous solution, an ionic liquid, or a liquid metal. The volume of the conductive droplets is generally 0.1uL to 10 mL.

Preferably, the material of the hydrophobic insulating layer comprises at least one of PTFE, Teflon AF, Cytop, Hyflon, PDMS. The thickness of the hydrophobic insulating layer is generally 10nm to 5mm, preferably 10nm to 10 um.

Preferably, step S1 specifically includes: and arranging a lower electrode layer on the lower substrate, arranging an insulating layer on the surface of the lower electrode layer, which is far away from the lower substrate, and arranging a hydrophobic insulating layer on the surface of the insulating layer, which is far away from the lower electrode layer.

Preferably, the material of the insulating layer is a silicon-based dielectric material, a fluoropolymer or Parylene.

The present invention also provides a hydrophobic insulating film having a patterned surface charge, which is manufactured by any of the above methods of manufacturing a patterned surface charge. The hydrophobic insulating film with the patterned surface charges can be applied to preparation of microfluidic devices, nanofluidic devices and micro-nano electronic devices, so that the invention also provides application of more than one hydrophobic insulating film with the patterned surface charges in preparation of microfluidic devices, nanofluidic devices or micro-nano electronic devices.

The beneficial technical effects of the invention are as follows: the invention provides a method for manufacturing patterned surface charges, a hydrophobic insulating film and application thereof. According to the principle of electrowetting technology, when voltage is applied between a lower electrode layer and an upper electrode in contact with a conductive liquid drop, the contact angle of the conductive liquid drop on the surface of a hydrophobic insulating layer is reduced, a wedge shape is formed at a solid-liquid-gas three-phase line of the conductive liquid drop, and the electric field intensity of a tip of the wedge shape is locally increased, so that bound charges are generated on the surface of the hydrophobic insulating layer and are gathered near the tip of the wedge shape formed at the edge of the liquid drop; because the surface charges are gathered near the three-phase line of the conductive liquid drop, the contact angle between the conductive liquid drop and the hydrophobic insulating layer is influenced by the electric field energy generated by the bound charges to change in the power-on process, the three-phase line of the conductive liquid drop moves in the power-on process, and the moving range of the three-phase line is the width range of the formed surface charges; therefore, the moving range of the three-phase line of the conductive liquid drop on the hydrophobic insulating layer can be controlled by controlling the applied voltage, and the pattern formed by the bound charges on the surface can be further controlled; meanwhile, the charge density of the surface bound charges can be adjusted by changing the magnitude of the applied voltage and the time of the applied voltage, and the surface potential of the hydrophobic insulating layer can be changed accordingly. Through the mode, the method for manufacturing the patterned surface charge can obtain the patterned surface charge by controlling the distribution setting of the conductive liquid drops or changing the sizes of the conductive liquid drops and the like by utilizing an external power supply, and can generate the patterned stable surface charge from a micrometer scale to a micro-nano system by controlling the form and displacement of solid-liquid-gas three-phase contact lines of the conductive liquid drops through the external power supply; the method is convenient, fast, simple and feasible, can be realized by applying smaller voltage, does not need expensive instruments and complex processes, and has low production cost.

Drawings

In order to more clearly illustrate the technical solution in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below.

FIG. 1 is a schematic view of a method of manufacturing a patterned surface charge of example 1;

FIG. 2 is a graph showing the results of measuring the surface potential and surface morphology of the material having patterned surface charges obtained in example 1;

FIG. 3 is a schematic view of a method of manufacturing a patterned surface charge according to example 2;

FIG. 4 is a photograph of a projection of the conductive drop edge three-phase line taken from the bottom of the lower substrate of FIGS. 3 (a) and (b), respectively, up;

FIG. 5 is a graph showing the results of measuring the surface potential and surface topography at the corresponding locations near the three-phase line of the original conductive droplet on the material with patterned surface charges obtained in example 2;

FIG. 6 is the surface potential (U) of the corresponding position on the surface of the hydrophobic insulating layer material obtained in example 3 at the three-phase line of the original conductive liquid drop_T) And surface charge density (σ)_T) Upon application of a voltage (U)_C) A graph of variation of (d);

FIG. 7 is the surface potential (U) of the corresponding position on the surface of the hydrophobic insulating layer material obtained in example 4 at the three-phase line of the original conductive liquid drop_T) And surface charge density (σ)_T) A plot of Time over Time of applied voltage (Time);

FIG. 8 is a schematic view of a method of manufacturing a patterned surface charge of example 5;

FIG. 9 is a schematic view of a method of manufacturing a patterned surface charge according to example 6;

fig. 10 is a graph showing the results of the surface charge stability test of the hydrophobic insulating layer material obtained in example 6.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.