Inclined micro-pillar array structure and its preparation device and method, and function control method

Abstract

The present invention discloses an inclined microcolumn array structure and a preparation device and method, as well as a function control method. The preparation method of the inclined microcolumn array structure comprises: using a femtosecond laser through a convex lens to focus on a polymer material template in an incident manner at a target angle; driving the polymer material template to move to achieve pattern processing; fully mixing a shape memory polymer and a curing agent at a mass ratio of 10:3, and pouring them on the surface of the polymer material template; heating at 60°C for 2 hours, and then heating at 100°C for 1 hour, performing a demoulding process after curing, and obtaining an inclined microcolumn array structure. The target angle satisfies: when the inclined microcolumn array structure is heated to the glass transition temperature T g When the inclined micro-pillar array is above the surface, a target pressure is applied to make the inclined micro-pillar array in a collapsed state with the ends connected. The inclined micro-pillar array structure can realize the dual functions of droplet manipulation and surface dry adhesion.

Description

Technical Field

[0001] The present invention relates to an inclined microcolumn array structure and a preparation device and method thereof, and a functional control method, and in particular to a preparation method of an inclined microcolumn array structure that realizes the dual functions of droplet manipulation and surface dry adhesion, an inclined microcolumn array structure that realizes the dual functions of droplet manipulation and surface dry adhesion, a functional control method for an inclined microcolumn array that realizes the dual functions of droplet manipulation and surface dry adhesion, and a preparation device for an inclined microcolumn array structure that realizes the dual functions of droplet manipulation and surface dry adhesion. Background Art

[0002] At present, the main methods for preparing micropillar arrays are: ion etching technology, electrochemical etching, ultraviolet lithography and other technologies. However, the photolithography or chemical etching method has a relatively complicated processing flow; the added chemical corrosion materials are prone to cause environmental pollution. These preparation methods are mainly applicable to the processing of the same parameters, and the operation is complicated, time-consuming, and has a limited scope of use. The prepared structure can only achieve a single function (droplet manipulation or dry adhesion). Summary of the invention

[0003] Based on this, in order to solve the technical defects that the traditional micro-pillar array structure can only realize the single function of droplet manipulation or surface dry adhesion, the present invention provides a method for preparing a tilted micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion, a tilted micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion, a method for functional manipulation of the tilted micro-pillar array that realizes the dual functions of droplet manipulation and surface dry adhesion, and a device for preparing a tilted micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion. The preparation method of the tilted micro-pillar array structure is simple, and the prepared tilted micro-pillar array structure can realize the dual functions of droplet manipulation and surface dry adhesion.

[0004] The present invention adopts the following technical solution to realize a method for preparing a tilted micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion, which comprises the following steps:

[0005] A femtosecond laser is used to focus on the polymer material template through a convex lens at a target angle of incidence;

[0006] Driving the polymer material template to move so as to make a pattern to be processed related to the micro-pillar array on the polymer material template;

[0007] After the shape memory polymer and the curing agent are fully mixed in a mass ratio of 10:3, the mixture is poured onto the surface of the polymer material template;

[0008] Heating at 60° C. for 2 hours, then heating at 100° C. for 1 hour, and performing a demoulding process after curing to obtain an inclined microcolumn array having an inclination angle of the target angle disposed on the polymer material template, thereby forming an inclined microcolumn array structure;

[0009] Wherein, the target angle satisfies: when the inclined micro-pillar array structure is heated to the glass transition temperature T g When the inclined micro-pillar array is above the upper surface, a target pressure is applied to make the inclined micro-pillar array in a collapsed state with the end parts connected to the end parts.

[0010] As a further improvement of the above solution, after the mixture of the shape memory polymer and the curing agent is poured on the surface of the polymer material template, vacuum is drawn to ensure that the shape memory polymer enters the structure of the polymer material template;

[0011] Preferably, the vacuum is applied for 10 minutes.

[0012] As a further improvement of the above solution, the target angle is 45°.

[0013] As a further improvement of the above solution, the polymer material template is a silica gel template, a polydimethylsiloxane template, or a polytetrafluoroethylene template.

[0014] As a further improvement of the above solution, the shape memory polymer is epoxy resin or bisphenol A diglycidyl ether.

[0015] The present invention also provides a tilted micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion, which comprises:

[0016] Polymer material template;

[0017] A micro-pillar array located on the polymer material template;

[0018] The micro-pillar array is produced by focusing a femtosecond laser through a convex lens at a target angle of incidence, thereby obtaining an inclined micro-pillar array having an inclination angle of the target angle;

[0019] The target angle satisfies: when the inclined micropillar array structure is heated to the glass transition temperature T g When the inclined micro-pillar array is above the upper surface, a target pressure is applied to make the inclined micro-pillar array in a collapsed state with the end parts connected to the end parts.

[0020] As a further improvement of the above solution, the inclined micro-pillar array structure is prepared by using any of the above methods for preparing an inclined micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion.

[0021] The present invention also provides a functional control method for realizing the dual functions of droplet control and surface dry adhesion by using a tilted micro-pillar array, which comprises the following steps:

[0022] (1) Realize the droplet manipulation function at the solid-liquid interface:

[0023] Providing any of the above-mentioned inclined micro-pillar array structures that realize the dual functions of droplet manipulation and surface dry adhesion;

[0024] The inclined micropillar array structure is heated to the glass transition temperature T g A target pressure is applied thereon to obtain an inclined micro-pillar array with a larger inclination angle, so that the current inclined micro-pillar array is in a collapsed state with the ends connected;

[0025] When the temperature drops to the glass transition temperature T g Under the above, the inclined micro-pillar array is kept in a collapsed state, so as to realize the control of the sliding behavior of the droplet;

[0026] The inclined micropillar array structure is heated again to the glass transition temperature T g above, restoring the inclined micro-pillar array with an inclination angle equal to the target angle;

[0027] (2) Realize the surface dry adhesion function between solid-solid interfaces:

[0028] Providing any of the above-mentioned inclined micro-pillar array structures that realize the dual functions of droplet manipulation and surface dry adhesion;

[0029] The inclined micropillar array structure is heated to the glass transition temperature T g In the above case, the inclined micro-pillar array of the inclined micro-pillar array structure is pressed onto the surface of the surface adherend until the inclined micro-pillar array forms a collapsed state;

[0030] When cooled to room temperature, the surface adherend is lifted into the air by the inclined micro-pillar array to achieve a dry adhesion function on the surface of the surface adherend;

[0031] The inclined micropillar array structure is heated again to the glass transition temperature T g Then, the inclined micro-pillar array is restored to have an inclination angle equal to the target angle, thereby releasing the adherent matter on the surface.

[0032] The present invention also provides a device for preparing an inclined micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion, which comprises:

[0033] A femtosecond laser, used for outputting femtosecond laser;

[0034] An incident angle adjuster, used to adjust the incident angle of the femtosecond laser on the polymer material template;

[0035] A convex lens, used to focus the femtosecond laser on the polymer material template in an incident manner at a target angle;

[0036] A moving platform, used for driving the polymer material template to move;

[0037] A controller, for controlling the femtosecond laser to output a femtosecond laser, and after the femtosecond laser is focused on the polymer material template through a convex lens in an incident manner at the target angle, controlling the moving platform to drive the polymer material template to move, so as to produce a pattern to be photolithographically processed related to the micro-pillar array on the polymer material template;

[0038] A container for fully mixing the shape memory polymer and the curing agent in a mass ratio of 10:3, and then pouring the mixture onto the surface of the polymer material template on which the pattern to be photolithographically patterned has been prepared;

[0039] A heater is used to heat the polymer material template with the mixture at 60° C. for 2 hours, and then heat it at 100° C. for 1 hour, and perform a demoulding process after curing to obtain an inclined microcolumn array with an inclination angle of the target angle set on the polymer material template, thereby forming an inclined microcolumn array structure;

[0040] Wherein, the target angle satisfies: when the inclined micro-pillar array structure is heated to the glass transition temperature T g When the inclined micro-pillar array is above the upper surface, a target pressure is applied to make the inclined micro-pillar array in a collapsed state with the end parts connected to the end parts.

[0041] As a further improvement of the above solution, the incident angle adjuster is a plurality of reflectors, and the reflectors are used to change the light path.

[0042] As a further improvement of the above solution, the preparation device also includes: an attenuation plate and at least one optical gate; the attenuation plate is used to attenuate the optical signal energy of the femtosecond laser, and the optical gate is used to perform unidirectional light isolation of the femtosecond laser.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The present invention adopts femtosecond laser tilted micro-nano processing technology and template replication technology to prepare tilted micro-column arrays. Compared with the existing processing methods, the method is simple, widely applicable, and environmentally friendly.

[0045] 2. Since it is made of shape memory polymer, the inclined micropillar array has shape memory function and can achieve conversion between temporary shape and permanent shape.

[0046] 3. The shape memory function of the tilted micropillar array can be used to achieve droplet manipulation and surface dry adhesion. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a partial structural schematic diagram of a device for preparing an inclined micro-pillar array structure according to Example 1 of the present invention.

[0048] Figure 2 The present invention is a flow chart illustrating the process of the method for preparing the inclined micropillar array structure of the present invention.

[0049] Figure 3 This is a dual state change diagram of the inclined micro-pillar array structure of the present invention.

[0050] Figure 4 The electron microscope comparison images of the morphology of the inclined micro-pillar array structure with different element spacing in the collapsed state.

[0051] Figure 5 Schematic diagram of the state change of the inclined micro-pillar array structure of the present invention to realize the droplet manipulation function.

[0052] Figure 6 It is a schematic diagram of the state change of the inclined micro-pillar array structure of the present invention to achieve the surface dry adhesion function. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time. When a component is considered to be "fixed to" another component, it may be directly fixed on the other component or there may be a central component at the same time.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0056] The preparation device of the present invention is used to prepare an inclined micro-pillar array structure, which can realize the dual functions of droplet manipulation and surface dry adhesion. Figure 1, Figure 1 The main components of the preparation device are shown in the figure: femtosecond laser 1, incident angle adjuster, convex lens 2, mobile platform 3, incident angle adjuster, attenuation plate 5, at least one optical shutter. The preparation device also includes a controller (not shown), a container (not shown), and a heater (not shown), which are not shown in the figure due to space limitations.

[0057] The femtosecond laser 1 is used to output femtosecond laser. The femtosecond laser can be generated by Coherent's ChameleonVision-S seed laser and Legend Elite F HE-1K titanium sapphire chirped pulse amplification system, and its wavelength, pulse width and frequency are 800nm, 104fs and 1kHz respectively.

[0058] The incident angle regulator is used to adjust the incident angle of the femtosecond laser on the polymer material template 8. The incident angle regulator can be a reflector 4, and the reflector 4 is used to change the optical path. In the present embodiment, a plurality of reflectors 4 are provided, and the specific number of reflectors 4 is convenient for adjusting the incident angle of the femtosecond laser on the polymer material template 8. The attenuation plate 5 is used to attenuate the optical signal energy of the femtosecond laser, and the optical gate is used to perform unidirectional isolation of the light of the femtosecond laser. The optical gate can adopt a fixed optical gate 6 with a fixed aperture, or an electronic optical gate 7, and of course, it can also be universal, and the number is not limited. When there is an electronic optical gate 7 in the optical gate used, the aperture of the electronic optical gate 7 can be controlled by a controller.

[0059] The polymer material template 8 can be a silica template, a polydimethylsiloxane template, or a polytetrafluoroethylene template. In this embodiment, the polymer material template 8 uses a silica substrate. The same effect can also be achieved by using polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE) and other materials.

[0060] The propagation direction of the femtosecond laser can be changed by the reflector 4, and finally the convex lens 2 is focused on the surface of the silicone substrate at a tilted target angle, such as a 45° angle. In other embodiments, the target angle can meet the following conditions: when the tilted micropillar array structure is heated to the glass transition temperature T g When the inclined micro-pillar array is above the upper limit, a target pressure is applied to make the inclined micro-pillar array in a collapsed state with the ends connected. The target pressure is not particularly limited, as long as it can press down the inclined micro-pillar array to make the inclined micro-pillar array in a collapsed state with the ends connected.

[0061] The mobile platform 3 is used to drive the polymer material template 8 to move, and the controller is used to control the femtosecond laser 1 to output the femtosecond laser, and after the femtosecond laser is focused on the polymer material template 8 through the convex lens 2 in the incident manner of the target angle, the mobile platform 3 is controlled to drive the polymer material template 8 to move, so as to produce a pattern to be photolithography related to the microcolumn array on the polymer material template 8.

[0062] The container is used to fully mix the shape memory polymer and the curing agent in a mass ratio of 10:3, and then pour it on the surface of the polymer material template 8 on which the pattern to be photolithography has been made. In this embodiment, after the mixture of the shape memory polymer and the curing agent is poured on the surface of the polymer material template 8, vacuuming is performed to ensure that the shape memory polymer enters the structure of the polymer material template 8, such as vacuuming for 10 minutes. The type of shape memory polymer is selected. In this embodiment, epoxy resin E51 is used. Other types of shape memory polymers can also be used to obtain corresponding structures, such as bisphenol A diglycidyl ether.

[0063] The heater is used to heat the polymer material template 8 with the mixture at 60°C for two hours, and then heat it at 100°C for 1 hour, and perform a demoulding process after curing to obtain an inclined micro-pillar array with an inclination angle of the target angle set on the polymer material template 8, forming an inclined micro-pillar array structure. Micro-pillar arrays with different inclination angles can be obtained by adjusting the incident angle of the femtosecond laser.

[0064] In this embodiment, after the silicone template is processed, it is treated with a release agent. The shape memory polymer E51 and the curing agent are fully mixed in a mass ratio of 10:3, and then poured on the surface of the template. Vacuum for 10 minutes to ensure that the shape memory polymer enters the structure. Heat at 60°C for 2 hours and then at 100°C for 1 hour to obtain the cured and demolded microcolumn array with an inclination angle of 45°. The transfer process is as follows Figure 2 shown.

[0065] The inclined micro-pillar array structure manufactured by the present invention structurally comprises a polymer material template 8, a micro-pillar array 9 located on the polymer material template 8, as shown in FIG. Figure 3 The glass transition temperature (T g ) is 77°C. g It is related to the type and ratio of materials. Heat the microcolumn array to T g When the temperature is above T, a certain pressure is applied to obtain a micropillar array with a larger tilt angle (collapsed state). g When the micro-pillar array 9 is below T, the micro-pillar array 9 can maintain the collapsed state (temporary shape). The collapsed micro-pillar array is heated again to Tg Above this, it can be restored to the micro-pillar array 9 tilted at 45° (permanent state).

[0066] like Figure 4 As shown in Figure 2, micropillar arrays with different structural parameters can be easily prepared by changing the processing parameters. After collapse, the micropillar array with small spacing forms a messy structure ( Figure 4 In region a), the structures with large spacing form a "head-to-tail" structure ( Figure 4 Therefore, the target angle satisfies: when the inclined micropillar array structure is heated to the glass transition temperature T g When the inclined micro-pillar array is above the upper surface, a target pressure is applied to make the inclined micro-pillar array in a collapsed state with the end parts connected to the end parts.

[0067] The dry adhesion force of the collapsed micropillar array surface is smaller than that of the original tilted micropillar array surface. Based on this characteristic, the sliding behavior of the droplet can be controlled. Figure 5 ,like Figure 5 As shown in region a in the figure, the droplet can slide on the collapsed micropillar array and pin on the inclined micropillar array surface. Figure 5 Region b in the figure shows the actual situation of droplet manipulation.

[0068] Therefore, the functional manipulation method of the tilted micro-pillar array of the present invention realizes the dual functions of liquid droplet manipulation at the solid-liquid interface and surface dry adhesion between the solid-solid interface, and the steps of realizing the liquid droplet manipulation function at the solid-liquid interface are as follows:

[0069] The inclined micropillar array structure is heated to the glass transition temperature T g A target pressure is applied thereon to obtain an inclined micro-pillar array with a larger inclination angle, so that the current inclined micro-pillar array is in a collapsed state with the ends connected;

[0070] When the temperature drops to the glass transition temperature T g Under the above, the inclined micro-pillar array is kept in a collapsed state, so as to realize the control of the sliding behavior of the droplet;

[0071] The inclined micropillar array structure is heated again to the glass transition temperature T g Then, the tilted micropillar array is restored to have a tilt angle equal to the target angle.

[0072] See also Figure 6 The inclined micropillar array of the present invention can also achieve dry adhesion between solid-solid interfaces ( Figure 6Area a in the figure). This property can be used to transfer surface adherents such as smooth and fragile objects. In this embodiment, a cover glass is used as a demonstration. When heated, the inclined micro-pillar structure is pressed against the surface of the cover glass to form a collapsed state. When cooled to room temperature, the micro-pillar array can lift the cover glass. When heated again, the micro-pillar array can return to the inclined state to release the cover glass ( Figure 6 Middle area b).

[0073] Therefore, the functional manipulation method of the tilted micro-pillar array of the present invention realizes the dual functions of droplet manipulation at the solid-liquid interface and surface dry adhesion between the solid-solid interface, and the steps of realizing the surface dry adhesion function between the solid-solid interface are as follows:

[0074] The inclined micropillar array structure is heated to the glass transition temperature T g In the above case, the inclined micro-pillar array of the inclined micro-pillar array structure is pressed onto the surface of the surface adherend until the inclined micro-pillar array forms a collapsed state;

[0075] When cooled to room temperature, the object to be adhered to the surface is lifted into the air by the inclined micro-pillar array to achieve a dry adhesion function on the surface of the object to be adhered to the surface;

[0076] The inclined micropillar array structure is heated again to the glass transition temperature T g Then, the inclined micro-pillar array is restored to have an inclination angle equal to the target angle, thereby releasing the adherent matter on the surface.

[0077] Compared with the traditional method of preparing inclined micro-pillars, the femtosecond laser inclined micro-nano processing and template transfer method of the present invention is simpler, and the inclined micro-pillar array structure prepared by the present invention can realize the dual functions of droplet manipulation and surface dry adhesion. The inclined micro-pillar structure realizing multiple functions at the same time has not been reported in previous work.

[0078] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention application shall be subject to the attached claims.

Claims

1. A method for preparing a tilted micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion, characterized in that: It includes the following steps: A femtosecond laser is used to focus on the polymer material template through a convex lens at a target angle, wherein the target angle is 45°; Driving the polymer material template to move so as to make a pattern to be processed related to the micro-pillar array on the polymer material template; After the shape memory polymer and the curing agent are fully mixed in a mass ratio of 10:3, the mixture is poured onto the surface of the polymer material template; Heating at 60° C. for 2 hours, then heating at 100° C. for 1 hour, and performing a demoulding process after curing to obtain an inclined microcolumn array having an inclination angle of the target angle disposed on the polymer material template, thereby forming an inclined microcolumn array structure; Wherein, the target angle satisfies: when the inclined micro-pillar array structure is heated to the glass transition temperature T g When the shape memory polymer and the curing agent are mixed, the shape memory polymer is ensured to enter the structure of the polymer template by vacuuming for 10 minutes.

2. The method for preparing the inclined micro-pillar array structure with dual functions of droplet manipulation and surface dry adhesion according to claim 1, characterized in that: The polymer material template is a silica gel template, a polydimethylsiloxane template, or a polytetrafluoroethylene template.

3. The method for preparing the inclined micro-pillar array structure with dual functions of droplet manipulation and surface dry adhesion according to claim 1, characterized in that: The shape memory polymer is epoxy resin or bisphenol A diglycidyl ether.

4. A tilted micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion, comprising: Polymer material template; A micro-pillar array located on the polymer material template; It is characterized in that The micro-column array is produced by focusing a femtosecond laser through a convex lens at an incident angle of a target, thereby obtaining an inclined micro-column array having an inclination angle of the target angle; Wherein, the target angle satisfies: when the inclined micro-pillar array structure is heated to the glass transition temperature T g When the inclined microcolumn array is in a collapsed state with its head and tail connected, a target pressure is applied; the inclined microcolumn array structure is prepared by the method for preparing an inclined microcolumn array structure having dual functions of droplet manipulation and surface dry adhesion as described in any one of claims 1 to 3.

5. A functional manipulation method for realizing the dual functions of droplet manipulation and surface dry adhesion by using a tilted micro-pillar array, characterized in that: It includes the following steps: (1) Realize the droplet manipulation function at the solid-liquid interface: Providing a tilted micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion as claimed in claim 4; The inclined micropillar array structure is heated to the glass transition temperature T g A target pressure is applied thereon to obtain an inclined micro-pillar array with a larger inclination angle, so that the current inclined micro-pillar array is in a collapsed state with the ends connected; When the temperature drops to the glass transition temperature T g Under the above, the inclined micro-pillar array is kept in a collapsed state, so as to realize the control of the sliding behavior of the droplet; The inclined micropillar array structure is heated again to the glass transition temperature T g above, restoring the inclined micro-pillar array with an inclination angle equal to the target angle; (2) Realize the surface dry adhesion function between solid-solid interfaces: Providing a tilted micro-pillar array structure that realizes the dual functions of droplet manipulation and surface dry adhesion as claimed in claim 4; The inclined micropillar array structure is heated to the glass transition temperature T g In the above case, the inclined micro-pillar array of the inclined micro-pillar array structure is pressed onto the surface of the surface adherend until the inclined micro-pillar array forms a collapsed state; When cooled to room temperature, the surface adherend is lifted into the air by the inclined micro-pillar array to achieve a dry adhesion function on the surface of the surface adherend; The inclined micropillar array structure is heated again to the glass transition temperature T g Then, the inclined micro-pillar array is restored to have an inclination angle equal to the target angle, thereby releasing the adherent matter on the surface.

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