阅读说明：本技术 一种焦距可调的仿生鹰眼、制备方法及应用 (Focal length-adjustable bionic eagle eye, preparation method and application ) 是由 孙洪波 曹嘉冀 陈岐岱 于 2019-09-10 设计创作，主要内容包括：本发明公开了一种焦距可调的仿生鹰眼、制备方法及应用,属于仿生光学元器件制备技术领域,本发明利用柔性材料PDMS翻模制备出具有扁圆柱型槽孔和微通道的支撑层结构,并将柔性PDMS平膜与该支撑层结构进行键合,围成中空的仿鹰眼角膜透镜/晶状体透镜结构,制备得到焦距可调的仿生鹰眼,所述仿生鹰眼为一集成有微流控通道的变焦透镜组双层结构,由下到上依次包括睫状肌驱动器、晶状体透镜、角膜驱动器及角膜透镜；同时,通过引入微通道结构,可向仿鹰眼角膜透镜/晶状体透镜通入液体,PDMS平膜即在液体或气体压力下快速扩张并向上凸起,使得仿鹰眼角膜透镜/晶状体透镜的焦距发生显著变化,从而实现了焦距可调的仿生鹰眼结构的低成本加工。(the invention discloses a bionic eagle eye with adjustable focal length, a preparation method and application, belonging to the technical field of preparation of bionic optical components.A supporting layer structure with an oblate cylindrical groove hole and a micro-channel is prepared by turning over a mould by using a flexible material PDMS (polydimethylsiloxane), and a flexible PDMS flat membrane is bonded with the supporting layer structure to form a hollow eagle eye corneal lens/crystalline lens structure in a surrounding manner, so that the bionic eagle eye with the adjustable focal length is prepared, is a double-layer structure of a zoom lens group integrated with a micro-fluidic channel and sequentially comprises a ciliary muscle driver, a crystalline lens, a corneal driver and a corneal lens from bottom to top; meanwhile, liquid can be introduced into the eagle eye-imitating cornea lens/crystalline lens by introducing the micro-channel structure, and the PDMS flat membrane rapidly expands and protrudes upwards under the pressure of liquid or gas, so that the focal length of the eagle eye-imitating cornea lens/crystalline lens is remarkably changed, and the low-cost processing of the eagle eye-imitating structure with the adjustable focal length is realized.)

1. A bionic eagle eye with adjustable focal length is characterized in that the bionic eagle eye is a zoom lens group double-layer structure integrated with a micro-fluidic channel and sequentially comprises a ciliary muscle driver (1), a lens (2), a cornea driver (3) and a cornea lens (4) from bottom to top;

The ciliary muscle driver (1) comprises a lens supporting layer (5), a lens tissue liquid channel (6) and a bionic eagle eye supporting layer (7); the lens tissue fluid channel (6) is positioned on the upper surface of the bionic eagle eye supporting layer (7), a tissue fluid medium (8) is introduced into the lens (2) through the channel, the curvature and the focal length of the lens (2) are regulated and controlled, and stable support is provided for the lens;

the lens (2) is a hollow cylindrical structure surrounded by a bionic eagle eye supporting layer (7) at the bottom, a lens epithelial membrane (9) at the top and lens supporting layers (5) at the periphery, penetrates through the lens supporting layer (5) up and down and is orthogonally communicated with the lens tissue liquid channel (6), and plays a role in deflected light imaging;

the cornea driver (3) comprises a cornea lens supporting layer (10) and a cornea tissue fluid channel (11); wherein, the corneal tissue fluid channel (11) is positioned on the upper surface of the lens epithelial membrane (9), and the corneal lens (4) is filled with the tissue fluid medium (8) through the channel, so as to regulate and control the curvature and the focal length of the corneal lens (4) and provide stable support for the corneal lens (4);

the corneal lens (4) is a hollow cylindrical structure surrounded by a lens epithelial film (9) at the bottom, a corneal epithelial film (12) at the top and a corneal lens supporting layer (10) at the periphery, penetrates through the corneal lens supporting layer (10) up and down and is orthogonally communicated with a corneal tissue fluid channel (11), and plays a role in deflected light imaging.

2. the bionic eagle eye with the adjustable focal length of claim 1, wherein the bionic eagle eye supporting layer (7) is a glass slide with the thickness of 1-1.2 mm; the lens supporting layer (5) and the cornea lens supporting layer (10) are both PDMS flat films, and the film thickness is 1-3 mm; the lens epithelial film (9) and the cornea epithelial film (12) are flexible PDMS films, the film thickness is 60-150 μm, and the films can be obviously protruded upwards under the action of a tissue fluid medium (8) so as to realize the regulation and control of the curvature and the focal length of the lens (2) and the cornea lens (4); the regulation and control range of the focal length is-2.43 mm- ∞.

3. The focal length adjustable bionic eagle eye according to claim 1, wherein the length of the lens tissue fluid channel (6) and the corneal tissue fluid channel (11) is 25-76mm, the diameter is 0.3-0.6mm, and two ports are communicated with the outside.

4. the focal length adjustable bionic eagle eye according to claim 1, wherein the interstitial fluid medium (8) is deionized water, and the refractive index is 1.33.

5. The preparation method of the bionic eagle eye with the adjustable focal length, which is characterized by comprising the following steps:

(1) Preparing a cornea lens supporting layer (10) and a lens supporting layer (5) by turning over;

The method comprises the following specific steps: firstly, preparing PDMS prepolymers for a corneal lens supporting layer (10) and a lens supporting layer (5), respectively weighing PDMS stock solution and a curing agent, and then manually stirring the PDMS stock solution and the curing agent uniformly by using a stirring rod to remove bubbles in the PDMS stock solution and the curing agent; then, two hard templates with a cornea lens supporting layer inverse structure and a lens supporting layer inverse structure are taken, sequentially subjected to ultrasonic cleaning for 10min by using acetone, ethanol and deionized water, and blown by ear balls to blow and dry surface moisture; then, uniformly dripping the PDMS prepolymer on two hard templates at one time respectively, and standing for 60-120min to enable the PDMS prepolymer to be self-leveling; subsequently, the two samples were placed on a heating stage for heat curing; finally, the solidified sample can be taken out after being naturally cooled, and the PDMS films on the two hard templates are lifted by using tweezers to obtain the needed lens tissue fluid channel (6), the lens supporting layer (5) around the lens tissue fluid channel, the cornea tissue fluid channel (11) and the cornea lens supporting layer (10) around the cornea tissue fluid channel;

(2) preparing a corneal epithelial film (12) and a lens epithelial film (9) by spin coating;

the method comprises the following specific steps: firstly, sequentially placing two glass slides in acetone, ethanol and deionized water for ultrasonic cleaning for 10min, and blowing dry the surface moisture of the glass slides by ear blowing balls; then, dropwise adding the PDMS prepolymer prepared in the step (1) on a glass slide, and carrying out spin coating by using a spin coater to obtain a PDMS flat film; subsequently, the two samples were placed on a heating stage and thermally cured; finally, after the sample is cooled to room temperature, separating the PDMS flat membrane from the glass slide to obtain a corneal epithelial membrane (12) and a lens epithelial membrane (9) in the bionic eagle eye;

(3) bonding to prepare a lens 2;

The method comprises the following specific steps: firstly, carrying out first oxygen plasma treatment on a glass slide and a lens supporting layer (5) to improve the surface hydrophilicity of the glass slide and the lens supporting layer; then, covering the processed lens support layer on the bionic eagle eye support layer (7), and attaching for the first time to obtain a lens support layer (5) on the bionic eagle eye support layer (7); subsequently, the sample is subjected to a second oxygen plasma treatment with the lens epithelial membrane (9); finally, covering the processed lens epithelial film (9) on the lens supporting layer (5), and performing second laminating to obtain the required lens (2);

(3) Bonding to prepare a corneal lens (4);

The method comprises the following specific steps: firstly, carrying out third oxygen plasma treatment on the lens (2) and the corneal lens support layer (10) obtained in the step (2) to improve the surface hydrophilicity of the lens and the corneal lens support layer; then, covering the processed cornea projection supporting layer (10) on the lens (2), and laminating for the third time to obtain a cornea supporting layer/lens double-layer structure; subsequently, the fourth oxygen plasma treatment is carried out on the obtained double-layer structure and the corneal epithelial membrane (12); and finally, covering the processed corneal epithelial membrane (12) above the double-layer structure, and laminating for the fourth time to finally obtain the required bionic eagle eye structure with adjustable focal length.

6. the method for preparing a focal length adjustable bionic eagle eye according to claim 5, wherein the customized corneal support layer hard template and lens support layer hard template in step (1) have opposite structures to those of the corneal lens support layer and the lens support layer, and are made of black high performance nylon capable of withstanding high temperature of 175 ℃.

7. The method for preparing a focal length adjustable bionic eagle eye according to claim 5, wherein the PDMS prepolymer is prepared by the following specific steps: firstly, weighing PDMS stock solution and a curing agent according to the weight ratio of 10:1, wherein the PDMS curing agent is a commercial matching reagent such as a silane coupling agent, and the two reagents are manually stirred and mixed for 1min by using a stirring rod; then, the obtained reagent is placed in a vacuum box at room temperature, the vacuum box is started and kept stand to remove air bubbles in the reagent, and the vacuum degree of the vacuum box is 1-10kPa for 10-25 min.

8. the method for preparing a focal length adjustable bionic eagle eye according to claim 5, wherein the custom-made corneal lens supporting layer hard template and lens supporting layer hard template are ultrasonically cleaned at a frequency of 20-70kHz for 10-30 min; the dosage of PDMS prepolymer dropped into two hard templates is 30-50 mL; the temperature for thermal curing is 60-80 deg.C, and the time is 60-120 min.

9. The method for preparing a bionic eagle eye with adjustable focal length according to claim 5, wherein the frequency of the ultrasonic cleaning of the slide glass in the step (2) is 20-70kHz, and the time is 10-30 min; the volume of the PDMS prepolymer dripped on the glass slide is 2-20mL, the rotating speed of spin coating of the spin coating is 700-2000r/min, and the time is 10-40 s; the temperature of the used heat curing is 60-80 ℃, and the time is 60-120 min; obtaining a PDMS flat film with the thickness of 40-120 m; performing the first and second oxygen plasma treatments in the step (3), wherein the vacuum degree is 2-4kPa, and the time is 30-60 s; and (4) performing the third oxygen plasma treatment and the fourth oxygen plasma treatment, wherein the vacuum degree is 2-4kPa, and the time is 30-60 s.

10. The use of the focal length adjustable bionic eagle eye of claim 1.

Technical Field

The invention belongs to the technical field of bionic optical component preparation, and particularly relates to a bionic eagle eye with focal length adjusting capability by utilizing a 3D printing template and an imprint transfer technology of a polymer, a preparation method and application.

Technical Field

bionic eagle eyes are inspired by the eyes of eagles in nature. The hawk flying over thousands of meters high can not only find the prey on the ground, but also dive down suddenly to catch the prey. The visual ability of the football field is equivalent to that ants on the ground can be clearly seen from a floor ten meters high, and the appearance of five sense organs of people at the other end can be clearly seen from one end of the football field with the green strewn. The visual acuity of the eagle, which is the first finger in vertebrates, is guaranteed by the special configuration of its eyes. The fovea is the most visually acute portion of the retina, on which a large number of photoreceptor cells are distributed. The human retina has only one fovea, while the eagle eye has two fovea distributed across it. The visual acuity of the eagle eye is improved, the visual angle range of the eagle is greatly expanded, and the binocular visual area of the eagle eye can reach 260 degrees which is 1.4 times that of a human. This ensures that the eagle eye has a wide-looking high resolution imaging capability. The eagle eye has the capability of 'double adjustment' different from human, and not only can change the shape of a crystalline lens through the contraction of ciliary muscles, but also can change the convexity of a cornea. By utilizing the double-adjustment capability, the lens in the eyeball is quickly converted between an ellipsoid and a sphere, and the lens can be equivalently regarded as a double-lens imaging system by matching with the change of the corneal curvature. Therefore, the eagle eye can be quickly switched between the telescope and the magnifier, the eagle eye can be ensured to telescope and magnify, a target can be found in a high altitude long distance, the target can be directly locked by diving, and the clear dynamic target tracking capability is provided for the eagle eye. Due to the advantages of clear and wide viewing of the eagle eye, the eagle eye-imitating vision technology is widely applied to the fields of aviation, aerospace, geology, traffic, security and the like.

Aiming at the excellent performance of the eagle eye, researchers at home and abroad carry out a great deal of research on the eagle eye. The maso corporation developed an eagle cell phone with 81.8 degrees large wide angle and 2.3 times optical zoom capability based on a wide-angle main lens and a telephoto lens in 2017. The group of lenses adopts a 3-time optical zoom lens provided by Hoya corporation of Japan, and the thickness of the lens is only 6 mm. An engineer group at stuttgart university in germany designs and prepares 2 doublets of 2 × 2 arrays of four lenses of different focal lengths, achieving a full field of view with an increasing angular resolution of 70 degrees with up to 2 cycles/degree field of view in the center of the image. After the images are obtained by the group of lenses, the images at different positions can be clearly integrated into a target by combining an image processing technology, so that the 'eyesight' like eagle is achieved. The method allows rapid design iteration without assembly, and can be applied to the fields of optical metrology, optical sensing, unmanned aerial vehicle investigation or security protection and the like. A visual imaging device with the resolution of the eagle eye is designed and developed by professor seashore of the university of Beijing aerospace in 2016, and comprises a left eye and a right eye, wherein each eye consists of 3 lenses with different resolutions. The device can autonomously select the lens to shoot and image according to the distance of a target object. The research work has pioneering significance in the field of optical imaging system research, but the designs have the problems of large volume, complex system, high manufacturing cost, poor biocompatibility and the like. Therefore, how to adopt a simple and low-cost scheme to quickly and flexibly design and produce a bionic eagle eye product with dynamic focusing capability becomes an important research direction in the field of optical imaging.

Disclosure of Invention

Aiming at the defects of the prior art, the technical problems to be solved by the invention are as follows: provides a bionic eagle eye with adjustable focal length. Preparing a supporting layer structure with an oblate cylindrical groove hole and a micro-channel by turning over a flexible material PDMS (polydimethylsiloxane), and bonding a flexible PDMS flat membrane with the supporting layer structure to form a hollow eagle eye-imitated corneal lens/crystalline lens structure in an enclosing manner; meanwhile, liquid can be introduced into the eagle eye-imitating cornea lens/crystalline lens by introducing the micro-channel structure, and the PDMS flat membrane rapidly expands and protrudes upwards under the pressure of liquid or gas, so that the focal length of the eagle eye-imitating cornea lens/crystalline lens is remarkably changed, and the low-cost processing of the eagle eye-imitating structure with the adjustable focal length is realized.

The invention is realized by the following technical scheme:

A bionic eagle eye with adjustable focal length is a zoom lens group double-layer structure integrated with a micro-fluidic channel and sequentially comprises a ciliary muscle driver 1, a lens 2, a cornea driver 3 and a cornea lens 4 from bottom to top;

the ciliary muscle driver 1 comprises a lens supporting layer 5, a lens tissue fluid channel 6 and a bionic eagle eye supporting layer 7; the lens tissue fluid channel 6 is positioned on the upper surface of the bionic eagle eye supporting layer 7, a tissue fluid medium 8 is introduced into the lens 2 through the channel, the curvature and the focal length of the lens 2 are regulated and controlled, and stable support is provided for the lens;

The lens 2 is a hollow cylindrical structure surrounded by a bionic eagle eye supporting layer 7 at the bottom, a lens epithelial film 9 at the top and lens supporting layers 5 at the periphery, penetrates through the lens supporting layer 5 up and down and is orthogonally communicated with the lens tissue fluid channel 6, and plays a role in deflected light imaging;

the cornea driver 3 comprises a cornea lens supporting layer 10 and a cornea tissue fluid channel 11; wherein, the corneal tissue fluid channel 11 is positioned on the upper surface of the lens epithelial membrane 9, and the corneal lens 4 is filled with the tissue fluid medium 8 through the channel, so as to regulate and control the curvature and the focal length of the corneal lens 4 and provide stable support for the corneal lens 4;

the corneal lens 4 is a hollow cylindrical structure surrounded by a lens epithelial film 9 at the bottom, a corneal epithelial film 12 at the top and a corneal lens support layer 10 at the periphery, penetrates through the corneal lens support layer 10 up and down and is orthogonally communicated with a corneal tissue fluid channel 11, and plays a role in deflecting light ray imaging.

Further, the bionic eagle eye supporting layer 7 is a glass slide, and the thickness is 1-1.2 mm; the lens supporting layer 5 and the corneal lens supporting layer 10 are both PDMS flat films, and the film thickness is 1-3 mm; the lens epithelial film 9 and the cornea epithelial film 12 are flexible PDMS films, the film thickness is 60-150 μm, and the films can be obviously protruded upwards under the action of the tissue fluid medium 8, so that the curvature and the focal length of the lens 2 and the cornea lens 4 can be regulated and controlled; the regulation and control range of the focal length is-2.43 mm- ∞.

Furthermore, the length of the lens tissue fluid channel 6 and the cornea tissue fluid channel 11 is 25-76mm, the diameter is 0.3-0.6mm, and two ports are communicated with the outside.

Further, the tissue fluid medium 8 is deionized water, and has a refractive index of 1.33.

A preparation method of a bionic eagle eye with adjustable focal length comprises the following specific steps:

(1) preparing a cornea lens supporting layer 10 and a lens supporting layer 5 by turning over the mold;

the method comprises the following specific steps: firstly, preparing PDMS prepolymers for a corneal lens supporting layer 10 and a lens supporting layer 5, respectively weighing PDMS stock solution and a curing agent, and then manually stirring the PDMS stock solution and the curing agent uniformly by using a stirring rod to remove bubbles in the PDMS stock solution and the curing agent; then, two hard templates with a cornea lens supporting layer inverse structure and a lens supporting layer inverse structure are taken, sequentially subjected to ultrasonic cleaning for 10min by using acetone, ethanol and deionized water, and blown by ear balls to blow and dry surface moisture; then, uniformly dripping the PDMS prepolymer on two hard templates at one time respectively, and standing for 60-120min to enable the PDMS prepolymer to be self-leveling; subsequently, the two samples were placed on a heating stage for heat curing; finally, the solidified sample can be taken out after being naturally cooled, and the PDMS films on the two hard templates are lifted by using tweezers to obtain the needed crystalline lens tissue fluid channel 6, the crystalline lens supporting layer 5 around the crystalline lens tissue fluid channel, the corneal tissue fluid channel 11 and the corneal lens supporting layer 10 around the corneal tissue fluid channel;

(2) Preparing a corneal epithelial film 12 and a lens epithelial film 9 by spin coating;

the method comprises the following specific steps: firstly, sequentially placing two glass slides in acetone, ethanol and deionized water for ultrasonic cleaning for 10min, and blowing dry the surface moisture of the glass slides by ear blowing balls; then, dropwise adding the PDMS prepolymer prepared in the step (1) on a glass slide, and carrying out spin coating by using a spin coater to obtain a PDMS flat film; subsequently, the two samples were placed on a heating stage and thermally cured; finally, after the sample is cooled to room temperature, separating the PDMS flat membrane from the glass slide to obtain the corneal epithelial membrane 12 and the lens epithelial membrane 9 in the bionic eagle eye;

(3) Bonding to prepare a lens 2;

the method comprises the following specific steps: firstly, carrying out first oxygen plasma treatment on a glass slide and a lens supporting layer 5 to improve the surface hydrophilicity of the glass slide and the lens supporting layer; then, covering the processed lens support layer on the bionic eagle eye support layer 7, and performing first laminating to obtain a lens support layer 5 positioned on the bionic eagle eye support layer 7; subsequently, this sample was subjected to a second oxygen plasma treatment with the lens epithelial film 9; finally, covering the processed lens epithelial film 9 on the lens supporting layer 5, and performing second laminating to obtain the required lens 2;

(3) Bonding to prepare a corneal lens 4;

The method comprises the following specific steps: firstly, carrying out third oxygen plasma treatment on the lens 2 and the corneal lens support layer 10 obtained in the step (2) to improve the surface hydrophilicity; then, covering the processed cornea projection supporting layer 10 on the lens 2, and laminating for the third time to obtain a cornea supporting layer/lens double-layer structure; subsequently, the fourth oxygen plasma treatment is performed on the obtained bilayer structure and the corneal epithelial film 12; and finally, covering the processed corneal epithelial film 12 above the double-layer structure, and laminating for the fourth time to finally obtain the required bionic eagle eye structure with adjustable focal length.

Further, the customized cornea support layer hard template and lens support layer hard template in the step (1) have the structures opposite to those of the cornea lens support layer and the lens support layer, and are made of black high-performance nylon and can resist the high temperature of 175 ℃.

Further, the specific preparation method of the PDMS prepolymer is as follows: firstly, weighing PDMS stock solution and a curing agent according to the weight ratio of 10:1, wherein the PDMS curing agent is a commercial matching reagent such as a silane coupling agent, and the two reagents are manually stirred and mixed for 1min by using a stirring rod; then, the obtained reagent is placed in a vacuum box at room temperature, the vacuum box is started and kept stand to remove air bubbles in the reagent, and the vacuum degree of the vacuum box is 1-10kPa for 10-25 min.

Further, the customized cornea lens supporting layer hard template and lens supporting layer hard template are subjected to ultrasonic cleaning, the frequency is 20-70kHz, and the time is 10-30 min; the dosage of PDMS prepolymer dropped into two hard templates is 30-50 mL; the temperature for thermal curing is 60-80 deg.C, and the time is 60-120 min.

Further, the frequency of the ultrasonic cleaning of the glass slide in the step (2) is 20-70kHz, and the time is 10-30 min; the volume of the PDMS prepolymer dripped on the glass slide is 2-20mL, the rotating speed of spin coating of the spin coating is 700-2000r/min, and the time is 10-40 s; the temperature of the used heat curing is 60-80 ℃, and the time is 60-120 min; the thickness of the obtained PDMS flat film is 40-120 μm.

Further, the first oxygen plasma treatment and the second oxygen plasma treatment in the step (3) are carried out, the vacuum degree is 2-4kPa, and the time is 30-60 s; and (4) performing the third oxygen plasma treatment and the fourth oxygen plasma treatment, wherein the vacuum degree is 2-4kPa, and the time is 30-60 s.

The invention also provides an application of the bionic eagle eye with adjustable focal length in optical imaging,

Compared with the prior art, the invention has the following advantages:

1. The bionic eagle eye system with the adjustable focal length is realized by utilizing the 3D printing and imprinting transfer technology, compared with the traditional zooming equipment which utilizes a plurality of groups of lenses to adjust the far and near focal lengths, the bionic eagle eye system has the advantages of small volume and low manufacturing cost, and the processing mode of imprinting transfer and plasma treatment greatly simplifies the preparation process of the zooming lens;

2. The cornea/crystalline lens is subjected to optical parameter regulation and control by utilizing the cornea/crystalline lens tissue fluid channel in the bionic eagle eye, and compared with a traditional system for carrying out combined imaging by utilizing a plurality of groups of lenses with fixed focal lengths, the system has the advantages of regulation and control and miniaturization, and can realize the change of a clearly focusing position more directly, quickly and flexibly. Meanwhile, the materials used in the bionic eagle eye have good biocompatibility and are expected to be applied to medical imaging systems such as endoscopes.

Drawings

FIG. 1 is a schematic structural view of a focal length adjustable bionic eagle eye according to the present invention;

FIG. 2 is a photograph of an optical microscope of a focal length adjustable bionic eagle eye according to the present invention;

FIG. 3 is a schematic view of adjusting the focal length of a bionic eagle eye by adding deionized water to a lens according to the present invention;

FIG. 4 is a schematic view of adjusting the focal length of a bionic eagle eye by introducing deionized water into a lens and introducing gas into a corneal lens;

FIG. 5 is a schematic diagram illustrating the adjustment of the focal length of a bionic eagle eye by introducing deionized water into a corneal lens according to the present invention;

FIGS. 6(1) - (4) are photomicrographs of dynamic adjustment process of a focal length adjustable bionic eagle eye according to the invention;

wherein: (1) a photomicrograph of the imaging effect observed when the bionic eagle eye lens system is not deformed; (2) a photomicrograph of an imaging effect observed in the process of driving the lens to change the shape of the corneal lens by using gas while injecting deionized water into the corneal lens; (4) a photomicrograph of the bionic eagle eye system which is adjusted to clearly see the imaging effect of the letter K array at the position of 1.5 mm.

In the figure: the bionic eye-protecting device comprises a ciliary muscle driver 1, a lens 2, a cornea driver 3, a cornea lens 4, a lens supporting layer 5, a lens tissue fluid channel 6, a bionic eagle eye supporting layer 7, a tissue fluid medium 8, a lens epithelial membrane 9, a cornea lens supporting layer 10, a cornea tissue fluid channel 11 and a cornea epithelial membrane 12.

Detailed Description

the technical scheme of the invention is further specifically described below by combining the attached drawings.