JP2018526505A - Pullable flexible ultra-phophophobic film, method for producing the same, and method for non-destructive transfer of droplets - Google Patents

Abstract

The present invention provides a pullable flexible ultra-phophophobic film, a method for producing the film, and a non-destructive transfer method for droplets. A template having an overhanging micro / nano structure is subjected to fluorination modification, a curable elastic material is poured into the template, and the curable elastic material is peeled from the original template to obtain an intermediate having a micro / nano structure. A plastic emulsion is spin-coated on the intermediate, cured, the cured film is peeled off, and fluorinated modification is performed to obtain a flexible ultra-liquidphobic film that can be pulled. The super lyophobic film exhibits good low wetting characteristics for almost any liquid, has good flexibility and tensile properties, and has a local solid-liquid contact area by operations such as surface tension and curvature. And the curvature can be changed, and the non-destructive movement of the droplet can be realized by adjusting the adhesion of the surface to the droplet. There is further provided a method for realizing droplet manipulation and non-destructive transfer utilizing a pullable flexible ultra-phobic surface.

Description

  The present invention relates to a pullable flexible ultra-phophophobic film, a manufacturing method thereof, and a non-destructive transfer method of droplets, and belongs to the technical field of micro droplet operation control.

  In recent years, planar microfluidic chips that manipulate droplets on surfaces have gained great interest. The planar microfluidic chip has advantages such as downsizing, integration, low reagent consumption, and high analysis speed as compared with the conventional channel microfluidic chip. Equipped with a channel microfluidic chip, such as easy direct contact with the sample, convenient for handling solid samples and generating droplet arrays, and no risk of clogging of the microchannels due to solid particles and bubbles Not have a lot of benefits.

  However, compared with conventional channel microfluidic chips driven by continuous fluids, current surface microfluidic chips still lack effective droplet manipulation methods. In recent years, the development of surface microdroplet manipulation techniques such as some light control, electromagnetic field control, mechanical vibration control and sound field excitation control has overcome some of the shortcomings of channel microfluidic technology. Drop manipulation techniques are severely limited in droplet composition, microfluidic droplet sample transmission path and direction, and the like. Currently, the mainstream plane droplet operation method is to drive the droplet by driving the droplet movement by electrowetting, embedding an electrode array on the substrate, and alternately applying a voltage to different electrodes. is there. System integration is difficult because the electrode array is embedded and a high drive voltage is required.

  In order to solve the technical problems as described above, it is an object of the present invention to provide a flexible super lyophobic film that can be pulled and a method for producing the same. By using the film, non-destructive movement of droplets can be realized.

  Another object of the present invention is to provide a non-destructive transfer method of droplets using the pullable flexible ultra-phophophobic film. By utilizing this method, it is possible to realize transmission of microdroplets of arbitrary components and sizes, and to overcome the drawbacks of conventional microdroplet operation control technology without any processing on microdroplets, The application range of the micro droplet operation control technology can be expanded.

In order to achieve the above object, the present invention provides a method for producing a pullable flexible ultra-phobic film. As shown in FIG. 1, specifically, the process of the manufacturing method is as follows.
(1) A step of performing fluorination modification on a template having an overhanging micro / nano structure and flowing a curable elastic material;
(2) after curing, peeling the curable elastic material from the original template to obtain an intermediate having a micro-nano structure corresponding to an overhanging micro-nano structure;
(3) spin-coating a plastic emulsion on the surface of the layer having a micro / nano structure corresponding to the overhanging micro / nano structure of the intermediate;
(4) a step of curing the spin-coated plastic emulsion to form a film; and (5) a step of peeling the cured film and performing fluorination modification to obtain the pullable flexible ultra-phophophobic film. including.

  In the manufacturing method, the super-lyophobic surface template having an overhanging micro / nano structure may be produced by dry etching or may be produced on a silicon substrate by wet etching. Preferably, the overhanging micro / nanostructure is T-shaped, inverted trapezoidal, spherical, nail-shaped, umbrella-shaped or mushroom-shaped.

In the production method, preferably, in step (1), the fluorination modification is performed by:
The surface of the overhanging micro / nanostructure of the original template is heat-treated by a chemical vapor deposition process, and deposition is performed in each direction of the overhanging micro / nanostructure with a fluorocarbon compound gas source in a plasma state. Create a hydrophobic fluorocarbon coating on the surface of the micro / nanostructure, or cause a chemical reaction on the surface of the overhanging micro / nanostructure of the original template by a single molecule self-assembly process. Producing a hydrophobic fluorocarbon compound coating on the surface of the nanostructure;
More preferably, the reagent used for the hydrophobic treatment (that is, the fluorocarbon compound) is a low surface energy such as trimethylchlorosilane (TMCS), hexamethyldisilazane (HMDS), and perfluorodecyltrichlorosilane (PFTS). Or a combination of a plurality of fluorine-containing reagents.

  In the manufacturing method, preferably, in step (1), the curable elastic material is polydimethylsiloxane, ethylene-propylene-diene terpolymer rubber, nitrile-butadiene rubber, cis-polybutadiene rubber, and chloroprene rubber. 1 type or the combination of 2 or more types is included.

  In the manufacturing method, in steps (2) and (4), the film forming method may be low temperature curing, and the curing temperature is typically less than 5 ° C.

  In the above production method, preferably, the spin coater is rotated at the time of spin coating with the plastic emulsion to obtain super-lyophobic films having different thicknesses at different rotational speeds. In step (3), the rotational speed of the spin coating is controlled to be 50 rpm to 2000 rpm.

  In the manufacturing method, preferably, in step (3), the plastic emulsion is an EVA emulsion or a polypropylene emulsion.

In the production method, preferably, in step (5), the fluorination modification is performed by:
The surface of the overhanging micro / nanostructure of the original template is heat-treated by a chemical vapor deposition process, and deposition is performed in each direction of the overhanging micro / nanostructure with a fluorocarbon compound gas source in a plasma state. Create a hydrophobic fluorocarbon coating on the surface of the micro / nanostructure, or cause a chemical reaction on the surface of the overhanging micro / nanostructure of the original template by a single molecule self-assembly process. Producing a hydrophobic fluorocarbon compound coating on the surface of the nanostructure;
More preferably, the reagent (ie, fluorocarbon compound) used for the fluorination modification is a low surface such as trimethylchlorosilane (TMCS), hexamethyldisilazane (HMDS), and perfluorodecyltrichlorosilane (PFTS). Includes one or more combinations of energetic fluorine-containing reagents.

  Moreover, this invention provides the flexible super-liquidphobic film which can be pulled | pulled manufactured by the said manufacturing method. The pullable flexible ultra-lyophobic film has excellent flexibility and tensile properties and can be bent or pulled greatly.

The present invention also provides:
Placing a droplet on the surface of the pullable flexible ultra-phophophobic film 1;
The surface of another pullable flexible ultraphobic film is brought into contact with the droplet to capture and move the droplet, and to increase the pitch of the micro / nanostructure and A liquid non-destructive transfer method comprising the step 3 of reducing the liquid contact area, dropping the liquid drop from the surface of the pullable flexible ultra-phophophobic film, and terminating the movement is provided.

  The method can realize non-destructive movement of a droplet without inputting external energy such as light, electromagnetic field, mechanical vibration and sound field excitation. Furthermore, the composition of the droplet, the transmission path and direction of the microfluidic droplet sample are not particularly limited, and the present invention is effective for any droplet.

  The non-destructive transfer of droplets provided by the present invention applies to a variety of different types and properties of droplets or mixtures thereof. Preferably, the droplets include droplets of different types and characteristics, a mixture of different droplets or a mixture of droplets and solid particles. More preferably, the liquid includes one or more combinations of aqueous solutions, milk, blood, plasma, and biochemical reagents.

  In the moving method, in the moving process, by utilizing the characteristics that the super-lyophobic film has good flexibility and good tensile property, the contact area and adhesive force between the droplet and the surface are reduced by pulling. It can be changed to achieve non-destructive movement of the droplets. In addition, the curvature of the surface can be reduced by bending, the contact area between the droplet and the surface and the adhesive force can be reduced, and non-destructive movement of the droplet can be realized. That is, preferably, in step 3, an increase in the pitch of the micro-nano structure can be realized by pulling or bending the pullable flexible ultra-lyophobic film.

  A super-lyophobic surface that exhibits low wettability and low adhesion properties to any liquid is ideal for surface microfluidic droplet manipulation. The present invention has developed a super-lyophobic surface material with a special overhanging microstructure based on micro-electromechanical system (MEMS) processing technology. The surface not only exhibits good low wetting properties to almost any liquid, but also has good flexibility and pullable properties, so that the surface solid-liquid contact can be achieved by operations such as surface pulling and bending. The area and the curvature can be changed, and the non-destructive transmission of the droplet can be realized by adjusting the adhesion force of the surface to the droplet.

  The technical content of the present invention is to combine a double soft copy process and low surface energy treatment to control the surface micro / nano structure, and to obtain a super-lyophobic surface with excellent low wetting characteristics. Utilizing the good flexibility and tensile properties of the super-liquidphobic surface, the local solid-liquid contact area and curvature can be changed by operations such as surface tension and curvature, and the adhesive force to the surface droplets Can be adjusted to achieve non-destructive movement and transmission of the droplets. The technical content of the present invention overcomes the drawbacks of the conventional microdroplet manipulation control technology and can realize the transmission of microdroplets of any component and size without any processing on the microdroplets. The application range of the droplet operation control technology can be expanded.

1 is a schematic view of a process for producing a pullable flexible ultra-lyophobic surface according to the present invention. FIG. FIG. 3 is a schematic diagram of droplet manipulation with a pullable flexible ultra-lyophobic surface according to the present invention. It is a figure which shows the process of the actual droplet operation by the pullable flexible super lyophobic surface concerning this invention.

In order to more clearly grasp the configuration requirements, purpose, and beneficial effects of the present invention, the technical contents of the present invention will be described in detail below, but it is understood that the scope of the present invention is limited. Should not be done.
<Example 1>

The present embodiment provides a method for producing a pullable flexible ultra-phobic film and includes the following steps.
(1) The original template having a T-type micro / nano structure was washed and dried, and then placed on a hot plate. The temperature of the hot plate was set to 150 ° C. A clean glass slide was placed next to the template and preheated for 3 minutes. Perfluorodecyltrichlorosilane (PFTS) was removed, 2 drops were dropped on a slide on a hot plate using a disposable pipette, and the surface of the original template on the hot plate was covered with a glass dish. In order to obtain the highest hydrophobic effect, it was heated on a hot plate for 4 minutes.
(2) Remove the covered glass dish, pour polydimethylsiloxane (PDMS), which is a curable elastic material prepared in advance, into a culture dish, place in a vacuum dryer at 80 ° C., and bake in a vacuum atmosphere for 2 hours to cure. The elastic elastic material PDMS was cured. After peeling off the curable elastic material PDMS, an intermediate having a T-type micro / nano structure on the surface was obtained.
(3) A PDMS intermediate having a T-type micro / nano structure on the surface is set on a spin coater so that the microstructure surface is facing up, and a liquid EVA emulsion is poured into the surface of the intermediate, and the rotational speed is 50 rpm to In the range of 2000 rpm, different spin coating speeds can be set according to the desired thickness. For example, at 100 rpm, the thickness is about 160 μm, and at 300 rpm, the thickness is about 80 μm.
(4) The EVA emulsion after spin coating was taken out together with the PDMS intermediate, and cured in a low temperature atmosphere of −4 ° C. or lower. Curing time increases with EVA emulsion thickness. After curing, the film was peeled from the PDMS intermediate having a T-type micro / nano structure, and an EVA film having a T-type micro / nano structure on the surface was obtained.
(5) An EVA film having a T-type micro / nano structure was set on a hot plate so that both ends were supported and suspended. The temperature of the hot plate was set to 70 ° C. A clean glass slide was placed next to the film and preheated for 3 minutes. Using a disposable pipette, several drops of perfluorodecyltrichlorosilane (PFTS) were dropped on a slide glass on a hot plate, and the hot plate was covered from above with a glass dish. In order to obtain the highest hydrophobic effect, the film was heated on a hot plate for 30 minutes to obtain a flexible ultra-liquidphobic film that can be pulled.
<Example 2>

This example provides a non-destructive transfer method for droplets. As in the process shown in FIG. 2, in this example, droplet operation and non-utilization are performed using the characteristics of the super lyophobic surface produced in Example 1 having good flexibility and good tensile properties. Destructive transfer can be performed. Specifically, the method includes the following steps.
First, the droplet 22 is placed on the super-lyophobic film 23.
Next, the flexible transparent super lyophobic film 21 produced in Example 1 is operated to capture droplets from the super lyophobic film 23.
Finally, pulling the super lyophobic film 21 to reduce the adhesion of the film to the droplets, dropping the droplets 22 from the film and moving them nondestructively to any other surface.
<Example 3>

This embodiment provides another non-destructive transfer method for droplets. In this example, droplet manipulation and non-destructive transfer can be performed using the characteristics of the super-lyophobic surface produced in Example 1 having good flexibility and good tensile properties. Specifically, the method includes the following steps.
First, the droplet 22 is placed on the super-lyophobic film 23.
Next, the flexible transparent super lyophobic film 21 produced in Example 1 is operated to capture droplets from the super lyophobic film 23.
Finally, by curving the super lyophobic film 21, the local curvature of the contact portion between the film and the droplet is changed, the adhesive force of the film to the droplet is reduced, and the droplet 22 is dropped from the film. Move to any other surface, non-destructively.

  FIG. 3 is a diagram showing an operation process in which a droplet is actually manipulated by the pullable flexible super-lyophobic surface according to the present invention to realize non-destructive movement of the droplet. FIG. 3 shows that non-destructive transmission of droplets can be effectively realized by employing the technique provided by the present invention.

Claims (10)

(1) A step of performing fluorination modification on a template having an overhanging micro / nano structure and flowing a curable elastic material;
(2) after curing, peeling the curable elastic material from the original template to obtain an intermediate having a micro-nano structure corresponding to the overhanging micro-nano structure;
(3) spin-coating a plastic emulsion on the surface of a layer having a micro-nanostructure corresponding to the overhanging micro-nanostructure of the intermediate;
(4) curing the spin-coated plastic emulsion to form a film; and (5) peeling the cured film and performing fluorination modification to obtain the pullable flexible ultra-phophophobic film. A method for producing a pullable flexible ultra-liquidphobic film comprising the steps of:   The manufacturing method according to claim 1, wherein the overhanging micro / nanostructure is T-shaped, inverted trapezoidal, spherical, nail-shaped, umbrella-shaped or mushroom-shaped. In step (1), the fluorination modification comprises
The surface of the overhanging micro / nanostructure of the original template is heat-treated by a chemical vapor deposition process, and vapor deposition is performed in each direction of the overhanging micro / nanostructure with a fluorocarbon compound gas source in a plasma state. Generating a hydrophobic fluorocarbon compound coating on the surface of the overhanging micro / nanostructure, or causing a chemical reaction on the surface of the overhanging micro / nanostructure of the original template by a single molecule self-assembly process, Producing a hydrophobic fluorocarbon compound coating on the surface of the overhanging micro-nanostructure,
The manufacturing method according to claim 1, wherein the reagent used for the fluorination modification preferably includes one or a combination of trimethylchlorosilane, hexamethyldisilazane, and perfluorodecyltrichlorosilane.   In step (1), the curable elastic material is a combination of one or more of polydimethylsiloxane, ethylene-propylene-diene terpolymer rubber, nitrile butadiene rubber, cis polybutadiene rubber, and chloroprene rubber. The manufacturing method of Claim 1 containing this.   The manufacturing method of Claim 1 which controls the rotation speed of the said spin coat so that it may become 50 rpm-2000 rpm in step (3).   The production method according to claim 1 or 5, wherein in step (3), the plastic emulsion is an EVA emulsion or a polypropylene emulsion. In step (5), the fluorination modification comprises
The surface of the overhanging micro / nanostructure of the original template is heat-treated by a chemical vapor deposition process, and vapor deposition is performed in each direction of the overhanging micro / nanostructure with a fluorocarbon compound gas source in a plasma state. Generating a hydrophobic fluorocarbon compound coating on the surface of the overhanging micro / nanostructure, or causing a chemical reaction on the surface of the overhanging micro / nanostructure of the original template by a single molecule self-assembly process, Producing a hydrophobic fluorocarbon compound coating on the surface of the overhanging micro-nanostructure,
The manufacturing method according to claim 1, wherein the reagent used for the fluorination modification preferably includes one or a combination of trimethylchlorosilane, hexamethyldisilazane, and perfluorodecyltrichlorosilane.   A flexible ultra-liquidphobic film that can be pulled and manufactured by the manufacturing method according to claim 1. Placing the droplet on the surface of the pullable flexible ultra-phophophobic film according to claim 8,
Step 2 of capturing and moving the droplet by contacting the surface of the pullable flexible ultra-phophophobic film according to claim 8 with the droplet; and Including increasing the pitch, reducing the solid-liquid contact area, dropping the droplets from the surface of the pullable flexible ultraphobic film and terminating the movement,
Preferably, the droplets include droplets of different types and characteristics, a mixture of different droplets or a mixture of droplets and solid particles, and one or more of aqueous solutions, milk, blood, plasma, and biochemical reagents. A non-destructive transfer method of droplets, more preferably including a combination of species.   10. The method of claim 9, wherein in step 3, the pitch of the micro / nanostructure is increased by pulling or bending the pullable flexible ultra-phobic film.

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