阅读说明：本技术 一种产生表面电荷的方法、装置和疏水绝缘层及其应用 (Method and device for generating surface charge, hydrophobic insulating layer and application thereof ) 是由 吴昊 弗里德里希·穆盖莱 周国富 于 2019-09-17 设计创作，主要内容包括：本发明提供一种能在疏水绝缘层上产生长期稳定存在的表面电荷的方法、装置和疏水绝缘层及其应用。该方法包括以下步骤：在疏水绝缘层上设置导电液体,将电极层与疏水绝缘层连接,通过导电液体和电极层对疏水绝缘层施加电压。通过本发明产生的表面电荷可以长期存在于潮湿甚至水环境中而不发生衰减。采用本发明所提供的方法对疏水绝缘层施加电压,电压越大,疏水绝缘层上产生的表面电荷越高；施加电压的时间越长,产生的表面电荷也就越高。该方法可以在常温大气压条件下进行,而且,经检测,本方法产生的表面电荷可以达到500μC/m<Sup>2</Sup>以上,相对于现有的制造表面电荷的技术而言,其产生的电荷密度显然更高。(The invention provides a method and a device for generating surface charges on a hydrophobic insulating layer, the surface charges being stable for a long time, the hydrophobic insulating layer and application of the hydrophobic insulating layer. The method comprises the following steps: a conductive liquid is provided on the hydrophobic insulating layer, an electrode layer is connected to the hydrophobic insulating layer, and a voltage is applied to the hydrophobic insulating layer through the conductive liquid and the electrode layer. The surface charge generated by the present invention can be present in a humid or even aqueous environment for a long period of time without decay. The method provided by the invention is adopted to apply voltage to the hydrophobic insulating layer, and the larger the voltage is, the higher the surface charge generated on the hydrophobic insulating layer is; the longer the voltage is applied, the higher the surface charge generated. The method can be performed at normal temperatureThe method is carried out under the condition of air pressure, and the surface charge generated by the method can reach 500 mu C/m through detection 2 As described above, the charge density generated by the method is significantly higher than that of the conventional technique for producing surface charges.)

1. A method of generating a surface charge in a hydrophobic insulating layer, comprising the steps of:

disposing a conductive liquid on a hydrophobic insulating layer, connecting an electrode layer with the hydrophobic insulating layer, and applying a voltage to the hydrophobic insulating layer through the conductive liquid and the electrode layer.

2. The method of claim 1, further comprising a dielectric layer connected between the hydrophobic insulating layer and the electrode layer.

3. The method according to claim 1, characterized in that an insulating protective layer is provided on the three-phase line created by the electrically conductive liquid and the hydrophobic insulating layer.

4. An apparatus for generating a surface charge in a hydrophobic insulating layer, comprising:

an electrode layer for connecting with the hydrophobic insulating layer;

the upper electrode is used for communicating the conductive liquid arranged on the hydrophobic insulating layer;

and a power supply for applying a voltage to the hydrophobic insulating layer through the electrode layer and the upper electrode.

5. The device of claim 4, wherein a dielectric layer is further disposed on the electrode layer.

6. The device according to claim 4, characterized in that the three-phase line created by the electrically conductive liquid and the hydrophobic insulating layer is provided with an insulating protective layer.

7. A hydrophobic insulation layer with surface charges, characterized in that it is produced by the method according to any of claims 1-3 or by the device according to any of claims 4-6.

8. The hydrophobic insulating layer of claim 7, which is applied to the fields of micro-nano fluids, micro-nano electronics, protein surface adsorption and power generation.

9. A microfluidic chip comprising the hydrophobic insulating layer of claim 7.

10. A microfluidic device comprising the microfluidic chip of claim 9.

11. An electricity generating device comprising the hydrophobic insulating layer of claim 7.

Technical Field

The invention relates to the technical field of hydrophobic materials, in particular to a method and a device for generating surface charges, a hydrophobic insulating layer and application thereof.

Background

The presence of surface charges has a great influence on the application of hydrophobic insulating materials in various technical fields, and the effect of the hydrophobic insulating materials is beneficial and disadvantageous. On the one hand, in the electrowetting field, surface charges (especially surface bound charges capable of stabilizing existence) can cause a device to generate a surface potential spontaneously under the condition that an applied electric field is zero, and the controllability of the applied electric field on the function of the device is influenced, so that the device is failed. For example, in an electrowetting display, if bound charges are generated on the surface of the hydrophobic insulating layer, the ink in the pixel cells cannot flow back or the flow back is incomplete. On the other hand, stable surface charges can be well utilized in other fields such as micro-nano fluid, micro-nano electron, biological protein surface adsorption, power generation and the like. For example, in biological protein adsorption studies, materials with stable surface charges can adsorb proteins more efficiently due to the presence of ionized side chains on the protein surface, thereby satisfying different research requirements and purposes.

In order to more efficiently utilize the surface charge for the related design, a method of manufacturing the surface charge must also be studied. The existing common method for manufacturing surface charges is corona discharge (corona discharge) technology for manufacturing electrets, but the technology has the disadvantages that the surface charges of the electrets are unstable, and the surface charges are rapidly attenuated when meeting water or a humid environment, so that the electrets are difficult to be put into practical application of hydrophobic insulating layers.

In view of the above problems, it is necessary to provide a method for generating a surface charge stably existing for a long period of time on a hydrophobic insulating layer.

Disclosure of Invention

The invention aims to provide a method and a device for generating surface charges on a hydrophobic insulating layer, the hydrophobic insulating layer and application thereof.

According to a first aspect of the invention, there is provided a method of generating a surface charge in a hydrophobic insulating layer, the method comprising, according to an embodiment of the invention, the steps of:

a conductive liquid is provided on the hydrophobic insulating layer, an electrode layer is connected to the hydrophobic insulating layer, and a voltage is applied to the hydrophobic insulating layer through the conductive liquid and the electrode layer.

Among them, the electrode layer may be a conductive film or a conductive flat plate, and non-limiting examples of materials thereof are metal, metal oxide, graphene, carbon nanotube, and the like. The conductive liquid may specifically be electrolyte liquid, ionic liquid, liquid metal, nano metal solution, etc., and may be, for example, NaCl solution, KCl ionic liquid, liquid mercury, liquid amalgam, liquid gallium alloy, nano silver paste. The hydrophobic insulating layer may be any hydrophobic insulating material with surface bound charges including, but not limited to, low surface energy fluoropolymer materials such as amorphous fluoropolymer materials, non-limiting examples of which are: PTFE, PDMS, Teflon AF, Cytop, Hyflon. In addition, the applied voltage does not exceed the voltage required to break down the hydrophobic insulation.

The invention has the beneficial effects that:

the invention provides a method capable of generating surface charges stably existing for a long time on the surface of a hydrophobic insulating layer, and the surface charges generated by the method can exist in humid or even water environment for a long time without attenuation. The method provided by the invention is adopted to apply voltage to the hydrophobic insulating layer, and the larger the voltage is, the higher the surface charge generated on the hydrophobic insulating layer is; the longer the voltage is applied, the higher the surface charge generated. The method can be carried out under the condition of normal temperature and atmospheric pressure, and moreover,through detection, the surface charge generated by the method can reach 500 mu C/m²As described above, the charge density generated by the method is significantly higher than that of the conventional technique for producing surface charges.

The selection of the conductive liquid with higher resistivity can increase the voltage required for puncturing the hydrophobic insulating layer and increase the upper limit of the charge density which can be accepted by the surface of the hydrophobic insulating layer.

According to an embodiment of the invention, a dielectric layer is further connected between the hydrophobic insulating layer and the electrode layer.

After the dielectric layer is added between the hydrophobic insulating layer and the electrode layer, a higher voltage is required for breaking down the hydrophobic insulating layer, which means that the hydrophobic insulating layer can bear a higher voltage, and the higher voltage can enable the surface of the hydrophobic insulating layer to gather more charges, so that higher charge density is generated.

According to the embodiment of the invention, the dielectric layer is made of an organic or inorganic material with high dielectric strength to play an insulating role, a non-limiting example is a silicon dioxide layer, preferably a silicon dioxide layer prepared by a thermal growth process, the silicon dioxide layer prepared by the thermal growth process is more compact, higher in purity and uniform in film thickness, and the voltage required for puncturing the hydrophobic insulating layer can be further increased, so that the upper limit of the charge density of charges on the surface of the hydrophobic insulating layer is effectively increased.

According to an embodiment of the invention, the three-phase line created between the conducting liquid and the hydrophobic insulating layer is provided with an insulating protective layer.

The tapered structure of the edge of the conductive liquid near the three-phase line region can locally increase the electric field intensity of the edge portion, more charges are easily accumulated, the generated surface charges are uneven, and meanwhile, the local increase of the electric field intensity can easily cause film breakdown. The insulating protective layer is arranged at the position, so that the problem can be avoided.

According to the embodiment of the invention, the insulation protective layer can be at least one of photoresist and insulating tape.

According to an embodiment of the invention, the hydrophobic insulating layer has a thickness of 10nm to 10 μm.

According to a second aspect of the present invention, there is provided an apparatus for generating a surface charge to a hydrophobic insulating layer, the apparatus comprising, according to an embodiment of the present invention:

an electrode layer for connecting with the hydrophobic insulating layer;

the upper electrode is used for communicating the conductive liquid arranged on the hydrophobic insulating layer;

and a power supply for applying a voltage to the hydrophobic insulating layer through the electrode layer and the upper electrode.

The process of generating the surface charge on the hydrophobic insulating layer by the device can be carried out under the condition of normal temperature and atmospheric pressure, and the surface charge generated on the hydrophobic insulating layer by the device can reach 520 mu C/m through detection²Above, the charge density is clearly higher than in the prior art, and the surface charge generated by the device can be present for a long time in humid or even aqueous environments without decay.

According to the embodiment of the invention, the electrode layer is also provided with a dielectric layer.

According to an embodiment of the invention, the three-phase line created by the electrically conductive liquid and the hydrophobic insulating layer is provided with an insulating protective layer.

According to a third aspect of the present invention, there is provided a hydrophobic insulating layer with surface charges, the hydrophobic insulating layer being produced by the above method or by the above apparatus according to an embodiment of the present invention.

Compared with the hydrophobic insulating layer with surface charges prepared by technologies such as corona discharge in the prior art, the surface charges on the hydrophobic insulating layer are more stable, and the hydrophobic insulating layer can exist in humid or even water environment for a long time without attenuation. In addition, after the hydrophobic insulating layer provided by the invention is placed in the air for 100 days, the charge density of the surface charge of the hydrophobic insulating layer is not attenuated, and the hydrophobic insulating layer has good long-term stability.

According to a fourth aspect of the invention, the invention provides an application of the hydrophobic insulating layer in the fields of micro-nano fluid, micro-nano electronics, protein surface adsorption and power generation.

According to a fifth aspect of the present invention, there is provided a microfluidic chip comprising the above-described hydrophobic insulating layer according to an embodiment of the present invention.

According to a sixth aspect of the present invention, the present invention provides a microfluidic device, which includes the above microfluidic chip according to an embodiment of the present invention, and the device can perform at least one function including, but not limited to, cell culture, cell stimulation, cell analysis, nucleic acid extraction, nucleic acid amplification, biochemical detection, immunoassay, environmental monitoring, and the like by using the microfluidic chip in the microfluidic device.

According to a seventh aspect of the present invention, there is provided a power generation device comprising the above-described hydrophobic insulating layer according to an embodiment of the present invention.

According to embodiments of the present invention, the power generation device includes, but is not limited to, a friction generator or other power generation devices and apparatuses known in the art that can generate power or improve power generation efficiency by using the hydrophobic insulating layer provided in the present invention and the surface charge thereon, and non-limiting examples thereof may be a vertical contact friction generator, a parallel sliding friction generator or other composite friction generators. In a friction generator, the hydrophobic insulating layer with surface charges is selected as a friction layer material, and the output power of the generating set can be effectively improved due to the high-density surface charges stably existing for a long time.

Drawings

Fig. 1 is a schematic operation diagram of an apparatus for generating a surface charge on a hydrophobic insulating layer according to an embodiment of the present invention.

Fig. 2 is a leakage current-voltage variation diagram of another embodiment of the present invention.

Fig. 3 is a charge density measurement plot of surface charge generated at different applied voltage levels and durations in accordance with yet another embodiment of the present invention.

Fig. 4 shows the result of the change in the charge density of the surface charge at different times in the surface charge stability experiment according to still another embodiment of the present invention.

FIG. 5 is a measurement of the charge density at 0h and 12h in a surface charge stability experiment according to yet another embodiment of the present invention.

Fig. 6 is a test result of loop current in a 100-day standing test in a surface charge stability test according to still another embodiment of the present invention.

Fig. 7 is a water environment test result of a surface charge stability experiment according to still another embodiment of the present invention.

Fig. 8 is a schematic configuration diagram of a power generation device in embodiment 7 of the present invention.

Detailed Description

The conception, the specific structure, and the technical effects produced by the present invention will be clearly and completely described in conjunction with the embodiments below, so that the objects, the features, and the effects of the present invention can be fully understood. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.