阅读说明：本技术 一种能够可视化测量的结构色膜及其制备方法和应用 (Structural color film capable of being visually measured and preparation method and application thereof ) 是由 张晨初 陈任飞 张健明 于 2019-11-12 设计创作，主要内容包括：本发明公开了一种能够可视化测量的结构色膜及其制备方法和应用,涉及激光表面微纳加工领域,该方法首先在成型透明的PDMS膜上涂覆一层墨水,墨水干燥后,会在PDMS膜表面制备一层墨水层,然后利用聚焦激光干涉光刻技术,采用超快激光器调节好相关参数后对样品进行处理,在样品表面加工出周期性的微纳沟槽阵列,得到所述的结构色表面。本发明公开了一种利用该结构色膜的制备方法,在柔性执行器上制备出结构色表面,在柔性执行器的变形过程中,对应结构色表面的颜色也会发生变化,以其相应结构色的颜色变化与变形的对应关系,实现了对柔性执行器弯曲角的非接触可视化测量。(The invention discloses a structural color film capable of being measured visually, a preparation method and application thereof, and relates to the field of laser surface micro-nano processing. The invention discloses a preparation method of a structural color film, which is characterized in that a structural color surface is prepared on a flexible actuator, the color of the corresponding structural color surface can be changed in the deformation process of the flexible actuator, and the non-contact visual measurement of the bending angle of the flexible actuator is realized according to the corresponding relation between the color change and the deformation of the corresponding structural color.)

1. The utility model provides a can visual measuring structure color film, its characterized in that, structure color film specifically comprises the smooth bottom plate in top and the visual measuring layer that covers at its top, just periodic micro-nano groove array has been seted up at the top of structure color film, the degree of depth of periodic micro-nano groove array is not less than the thickness on visual measuring layer.

2. The structural color film capable of being visually measured according to claim 1, wherein the preparation method of the bottom plate comprises the following specific steps:

according to the following steps of 10: 1, taking liquid polydimethylsiloxane and PDMS curing agent, uniformly mixing and stirring, spin-coating on a glass slide, and placing on a heating plate for heating and curing after spin-coating to obtain a cured PDMS film, namely a bottom plate.

3. A visually measurable structural color film according to claim 2 wherein said visually measurable layer is embodied as an ink layer cured on top of said base plate.

4. A method of making the structured color film of claim 3, comprising the steps of:

step one, according to 10: 1, taking liquid polydimethylsiloxane and PDMS curing agent, mixing and stirring uniformly, spin-coating on a glass slide, and placing on a heating plate for heating and curing after spin-coating to obtain a cured PDMS film;

cleaning the PDMS film in an ultrasonic cleaning instrument filled with deionized water, and drying the surface of the PDMS film by using an air cooler or naturally drying the PDMS film at room temperature after cleaning to obtain a clean PDMS film;

step three, coating a layer of black ink on the surface of the clean PDMS film obtained in the step two, and then placing the PDMS film at room temperature to dry the ink on the surface to obtain the PDMS film with an ink layer on the surface;

and fourthly, carrying out focused laser interference photoetching scanning treatment on the surface of the PDMS film with the ink layer on the surface obtained in the third step by utilizing a focused laser interference photoetching processing technology, and processing a periodic micro-nano groove array on the surface of the PDMS film to obtain the structural color film.

5. The method of claim 4, wherein the spin coating in the first step is performed by using a spin coater, the PDMS after mixing and stirring is dropped on the glass slide, the glass slide is kept at a rotation speed of 500r/min for 10s, and then at a rotation speed of 1500r/min for 60s, the glass slide is heated on the heater plate at a temperature of 80 ℃ to 100 ℃ for 3 to 4 hours, and the temperature error of the heating plate is ± 1 ℃.

6. The method as claimed in claim 5, wherein the focused laser interference lithography scanning described in step four is performed using a two-dimensional mobile station by first modulating the laser output from the laser into two beams having a spot size of 1 x 1cm²Two beams with the same energy are converged into 1X 1mm by two convex lenses²Square light spots; by means of the adjustment of the light path,the light beams are superposed on the sample in time and space, the laser beams are kept still, the converged square light spot is fixed, the sample moves relative to the light spot, and the movement of the platform is 0.1mm/s-1 m/s.

7. The method of claim 6, wherein the laser in step four has a center wavelength of 355nm, a pulse width of 10ns, a repetition rate of 10Hz, a laser interference angle of 7.54 degrees, and a laser intensity of 0.40mW/cm²The scanning speed of the laser was 0.2 mm/s.

8. Use of the structural colour film according to any of claims 1-7 in a flexible actuator, wherein the outer surface of the flexible actuator is in particular formed by the structural colour film.

9. A method for non-contact measurement of the bending angle of the flexible actuator according to claim 8, comprising the steps of;

irradiating the structure color film on the surface of the flexible actuator by using LED white light;

secondly, powering on and powering off the flexible actuator to enable the flexible actuator to generate periodic bending motion, and synchronously performing periodic bending motion on a structural color film on the flexible actuator;

synchronously acquiring image information of the change condition of diffraction fringes generated on the surface of the flexible actuator due to light source irradiation in the periodic bending motion process of the structural color film on the flexible actuator and deformation image information of the periodic bending motion of the flexible actuator;

fourthly, counting the corresponding relations of the color of any point on the surface of the structural color film, the deformation of the flexible actuator and the bending angle of the flexible actuator and the time in the periodic bending motion process by using a digital graph processing method;

and step five, determining the bending angle of the corresponding flexible actuator according to the color of any point on the surface of the structural color film at any time in the process of the periodic bending motion of the flexible actuator.

10. The method according to claim 9, wherein the color of any point is specified as an RGB value of any point in the graphic information.

Technical Field

The invention relates to the field of laser surface micro-nano processing, in particular to a preparation method and application of a structural color film on a Polydimethylsiloxane (PDMS) substrate.

Background

The surface microstructure under biological inspiration has unique functions, such as a super-hydrophobic lotus leaf surface, an anisotropic rice leaf surface, a desert beetle surface capable of collecting water mist, a gorgeous and colorful butterfly wing and other structural color surfaces, which are used as one of the surfaces, and light waves are refracted, diffusely reflected, diffracted or interfered to generate various colors due to the fact that the surface is provided with ultrathin wax layers, carved points, furrows, scales and other fine structures. For example, butterfly wings exhibit a bright and colorful color due to the ridged microstructure on the surface; the feathers of many birds can see extra bright color when being observed from a specific angle due to the microstructure on the surface, and the color can be changed when changing the angle; the structural color surfaces are not generated by pigments, have the advantages of fastness, environmental protection, iridescence effect and the like, and have wide application prospects in the fields of display, anti-counterfeiting, sensing and the like, thereby causing the application of the structural color film in related fields. Therefore, the preparation of the structural color film is receiving more and more attention, people are eagerly applying the structural color film to experimental production, especially preparing a structural color surface on a Polydimethylsiloxane (PDMS) film.

Polydimethylsiloxane (PDMS) has the characteristics of water resistance, hydrophobicity, high light transmittance, good biocompatibility, simple and quick manufacturing process and the like, is a transparent high-elasticity flexible material, and is widely applied to the fields of biomedical engineering, microfluidic chips, flexible actuators and the like. As an important component of the flexible actuator, PDMS has high elasticity, and can realize large deformation on the flexible actuator. The PDMS film is processed by using a focused laser interference technology to obtain a structural color film, and the method has a very good application prospect.

There are many methods for preparing a structured color surface on PDMS, and typical methods are: self-assembly method of silica microsphere, nano-imprinting and transfer printing method, etc. The microsphere self-assembly method is that nano silicon dioxide microspheres are self-assembled into a certain structure and arranged into photonic crystals, uncured PDMS is poured into the photonic crystals to fill gaps among the microspheres, and the silicon dioxide microspheres are removed by hydrofluoric acid corrosion after curing to synthesize the inverse opal structure. The method has complex manufacturing process, and hydrofluoric acid is also needed, which can cause certain damage to human bodies and the environment. Both nanoimprint and transfer printing rely on the existing diffraction grating, the flexible material before solidification is processed to obtain a periodic structure the same as that of the diffraction grating, the period is difficult to flexibly adjust, and in the case of complex patterns, the diffraction grating needs to be customized as a mold, so that the processing flexibility is low.

In summary, it is an urgent need to solve the technical problem of the present researchers to develop a method that is simple in process, high in preparation efficiency, flexible in pattern processing, suitable for large-area processing, free from any environmental pollution, and capable of rapidly realizing the preparation of a structure color surface on cured PDMS.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a structural color film capable of being visually measured, and a preparation method and application thereof, so as to solve the technical problem of complex process in the prior art.

The invention is realized by the following technical scheme:

the invention provides a structural color film capable of being visually measured, which is specifically composed of a bottom plate with a flat top and a visual measurement layer covering the top of the bottom plate, wherein the top of the structural color film is provided with a periodic micro-nano groove array, and the depth of the periodic micro-nano groove array is not less than the thickness of the visual measurement layer.

Further, the preparation method of the bottom plate specifically comprises the following steps:

according to the following steps of 10: 1, taking liquid polydimethylsiloxane and PDMS curing agent, uniformly mixing and stirring, spin-coating on a glass slide, and placing on a heating plate for heating and curing after spin-coating to obtain a cured PDMS film, namely a bottom plate.

Further, the visual measuring layer is specifically an ink layer cured on top of the bottom plate.

The invention also provides a preparation method of the structural color film, which comprises the following steps:

step one, according to 10: 1, taking liquid polydimethylsiloxane and PDMS curing agent, mixing and stirring uniformly, spin-coating on a glass slide, and placing on a heating plate for heating and curing after spin-coating to obtain a cured PDMS film;

cleaning the PDMS film in an ultrasonic cleaning instrument filled with deionized water, and drying the surface of the PDMS film by using an air cooler or naturally drying the PDMS film at room temperature after cleaning to obtain a clean PDMS film;

step three, coating a layer of black ink on the surface of the clean PDMS film obtained in the step two, and then placing the PDMS film at room temperature to dry the ink on the surface to obtain the PDMS film with an ink layer on the surface;

and step four, carrying out focused laser interference photoetching scanning treatment on the surface of the PDMS film with the ink layer on the surface obtained in the step three by utilizing a focused laser interference photoetching processing technology, and processing a periodic micro-nano groove array on the surface of the PDMS film to obtain the structural color film.

Further, the spin coating in the step one is performed by using a spin coater, firstly dropping the mixed and stirred PDMS on a glass slide, keeping the rotational speed of 500r/min for 10s, then keeping the rotational speed of 1500r/min for 60s, heating the glass slide on a heater plate, wherein the heating temperature is 80-100 ℃, the heating time is 3-4 hours, and the temperature error of the heating plate is +/-1 ℃.

Further, the focused laser interference photoetching scanning in the fourth step is realized by using a two-dimensional mobile station, and firstly, laser output by a laser is modulated into two beams with the spot size of 1 multiplied by 1cm²Two beams with the same energy are converged into 1 × 1mm by two convex lenses²Square light spots; the light path is adjusted to enable the light beam to be superposed on the sample in time and space, the laser beam is kept still, the converged square light spot is fixed, the sample moves relative to the light spot, and the movement of the platform is 0.1mm/s-1 m/s.

Further, the laser in the fourth step has the center wavelength of 355nm, the pulse width of 10ns, the repetition frequency of 10Hz, the laser interference angle of 7.54 degrees and the laser intensity of 0.40mW/cm²The scanning speed of the laser was 0.2 mm/s.

The invention also provides application of the structural color film in a flexible execution device, wherein the outer surface of the flexible execution device is specifically composed of the structural color film.

The invention also provides a non-contact measuring method for measuring the curvature of the flexible executive device, which comprises the following steps:

irradiating the structure color film on the surface of the flexible actuator by using LED white light;

secondly, powering on and powering off the flexible actuator to enable the flexible actuator to generate periodic bending motion, wherein a structural color film on the flexible actuator also performs periodic bending motion;

synchronously acquiring image information of the change condition of diffraction fringes generated on the surface of the flexible actuator due to light source irradiation in the periodic bending motion process of the structural color film on the flexible actuator and deformation image information of the periodic bending motion of the flexible actuator;

fourthly, counting the corresponding relations of the color of any point on the surface of the structural color film, the deformation of the flexible actuator and the bending angle of the flexible actuator and the time in the periodic bending motion process by using a digital graph processing method;

and step five, determining the bending angle of the corresponding flexible actuator according to the color of any point on the surface of the structural color film at any time in the process of the periodic bending motion of the flexible actuator.

Further, the color of any point is specifically an RGB value of any point in the graphic information.

The invention relates to a method for soil culture of anthurium andraeanum, which has the beneficial effects that:

(1) the structural color film on the molded transparent PDMS is prepared by the method, the surface of the PDMS film is processed with a periodic micro-nano groove array, the micro-nano groove array has optical characteristics similar to those of a diffraction grating, and various colors can be observed by observing at different angles under the irradiation of white light. Has vivid structural color surface characteristics.

(2) The structural color film is prepared on PDMS by utilizing the focused laser interference lithography technology, the molded transparent PDMS can be processed, the manufacturing process is simple, the processing speed is high, and the existing diffraction grating is not required to be relied on. Other chemical reagents are not needed in the processing process, the method is green and environment-friendly, and the technological parameters of the method are easy to control and easy to apply in actual experimental production.

(3) The PDMS structural color film prepared by the method has flexible and controllable processed patterns; and the interference light path can be adjusted, so that the period of the processed micro-nano groove can be adjusted, and the application range of the PDMS film is greatly enlarged.

(4) The preparation of the structural color film is combined with a flexible actuator, and a structural color surface is prepared at a specific position on a PDMS layer of the flexible actuator. By analyzing the change of the diffraction stripes on the surface of the structural color when the flexible actuator is bent, the relation between the diffraction stripes and the bending degree is found out, so that the non-contact visual measurement of the curvature of the flexible actuator is realized, and the measurement difficulty of the flexible actuator is greatly reduced.

Drawings

FIG. 1 is a diagram of an experimental apparatus for focused laser interference lithography according to the present invention;

FIG. 2 is a simulated light field pattern for focused laser interference lithography in accordance with the present invention;

FIG. 3 is a schematic diagram of the present invention for preparing a structural color film by using focused laser interference lithography

FIG. 4 is a surface topography of a structural color film prepared by focused laser interference lithography in accordance with embodiment 1 of the present invention;

FIG. 5 is a height diagram of a periodic micro-nano groove of a structural color film prepared by focused laser interference lithography in embodiment 1 of the present invention;

FIG. 6 is a view of an observation apparatus for structural colors in example 1 of the present invention;

FIGS. 7(a), (b), (c), (d), (e) and (f) are color images observed at different angles of the structural color film prepared by focused laser interference lithography in example 1 of the present invention;

FIG. 8 is a graph showing the relationship between the observed angle and the observed color wavelength of a structural color film produced by focused laser interference lithography in example 1 of the present invention;

FIG. 9 is a surface topography of a dolphin patterned structured color film prepared by focused laser interference lithography in example 2;

FIG. 10 is a height diagram of the periodic micro-nano grooves of the structural color film of the dolphin pattern prepared by focused laser interference lithography in example 2 of the present invention;

FIGS. 11(a), (b), and (c) are color images of dolphin pattern structure color film prepared by focused laser interference lithography in example 2 of the present invention, observed at different angles;

FIG. 12 is a drawing of an observation apparatus for preparing a structure color surface on a flexible actuator by focused laser interference lithography according to embodiment 3 of the present invention;

FIGS. 13(a), (b), (c), (d), (e), (f) (g) and (h) are color and deformation diagrams of the structural color surface in the deformation period prepared on the flexible actuator by using focused laser interference lithography in the embodiment 3 of the present invention;

fig. 14 is a graph showing a relationship between a bending angle and time of a flexible actuator for preparing a structural color surface on the flexible actuator by focused laser interference lithography in the whole deformation cycle according to embodiment 3 of the present invention;

fig. 15(a), (b), (c) are RGB vs. time graphs of typical points on the structural color surface prepared on the flexible actuator by using focused laser interference lithography processing in embodiment 3 of the present invention over the entire deformation period.

Detailed Description

In order to make the technical solutions of the present application better understood by those skilled in the art, the technical solutions of the present application will be clearly and completely described below in conjunction with the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It is noted that the term "comprising" in the description and claims of the present application is intended to cover a non-exclusive inclusion, e.g. a method comprising a list of steps is not necessarily limited to those steps explicitly listed, but may include other steps not explicitly listed or inherent to such methods. The embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail with reference to examples.