Microlens array preparation method based on fluid confinement additive, microlens array and application

Abstract

The invention provides a preparation method of a micro-lens array based on fluid confinement additive, the micro-lens array and application. The preparation method of the micro-lens array comprises the steps of constructing a patterned hydrophilic and hydrophobic gradient on a substrate, forming a confinement energy barrier at a hydrophilic and hydrophobic boundary to constrain movement of a solid / liquid / gas three-phase contact line, realizing confinement of liquid drops, and being beneficial to improving the manufacturing precision, performance and reliability of the micro-lens array. The invention further provides a microlens array and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of precision optical devices, and specifically relates to a preparation method of a microlens array based on fluid confinement additive, a microlens array and an application. Background Art

[0002] As a core component in high-end optical applications such as 3D display, augmented reality (AR) and virtual reality (VR), microlens arrays have received widespread attention in recent years. Its main function is to focus light into a predetermined pattern, thereby achieving image reconstruction, beam shaping and enhanced display effects. With the advancement of technology, the performance requirements for microlens arrays are getting higher and higher, and manufacturing technology is also constantly developing to meet these needs.

[0003] Traditional manufacturing methods for microlens arrays include precision grinding, thermal reflow, nanoimprinting, grayscale lithography, and energy beam direct writing. Among them, precision grinding is a mechanical processing method that uses abrasives to remove materials. In this way, the shape and surface smoothness of the lens can be precisely controlled. However, precision grinding often faces the problems of low processing efficiency and high cost when processing microlens arrays. In addition, there are certain challenges in controlling the surface smoothness of the microlens, especially for large-scale production, where thermal deformation during the grinding process and abrasive wear will affect the final optical performance. Thermal reflow technology uses a heat source to reflow the surface of the lens material, thereby realizing the forming of the microlens. This method can produce higher-quality microlens arrays at a lower processing cost, but it is very sensitive to the fluidity of the material and the forming conditions. When achieving large-scale production, the consistency and repeatability of the thermal reflow process are still key issues that need to be solved. Nanoimprinting technology forms a microlens array by applying pressure on the mold to press the material into the mold. This method can achieve high-precision and high-repeatability microstructure formation, but the manufacturing cost of its mold is high, and mold wear or uneven material flow may occur during the imprinting process, limiting its application in large-scale production. Grayscale lithography uses different exposure intensities to control the thickness of the photoresist to form complex microstructures. This method is suitable for high-precision microlens array manufacturing, but the curing process of the photoresist and the exposure uniformity have a significant impact on the quality of the final product. In addition, the cost of grayscale lithography is high and the process is complex. Energy beam direct writing technology directly writes on the surface of the material by precisely controlling the laser beam or electron beam to form the desired microstructure. This method has high resolution and flexibility, but the manufacturing efficiency is low, and the use of high-energy beams may cause thermal damage to the material.

[0004] In recent years, additive manufacturing technology based on inkjet printing has shown significant potential in the manufacture of microlens arrays. Inkjet printing technology uses photocurable fluid materials to control the injection and curing process of the liquid to achieve the formation of the microlens array. This method can achieve microlenses with high surface smoothness by optimizing the parameters of inkjet printing, which is crucial for improving optical performance. In addition, inkjet printing can produce uniform microlens arrays in a short time, which is suitable for large-scale production. Furthermore, compared with traditional manufacturing methods, inkjet printing has higher production efficiency and can significantly reduce manufacturing costs. However, inkjet printing technology still faces challenges in achieving high filling factors and flexible curvature control. Specifically, in the inkjet printing process, how to accurately control the injection amount and curing process of the liquid to achieve a high filling factor (i.e., the overall filling ratio of the lens) is a key issue. Too low a filling factor may cause the performance of the microlens array to be substandard and affect the optical effect. The curvature of the microlens directly affects its optical performance. In the inkjet printing process, how to achieve flexible and precise curvature control to meet different application requirements is another important challenge. The current inkjet printing technology still needs to be further optimized in controlling the fluidity and curing rate of the liquid to achieve higher curvature adjustment accuracy. In the inkjet printing process, how to accurately control the diffusion and interface shape of the liquid to ensure the precision and reliability of the finished product is a key technical issue in additive manufacturing. The confinement and control of the liquid directly affects the optical performance and production consistency of the final microlens. The importance of microlens arrays in optical display technology continues to increase. Although traditional manufacturing methods have their own advantages and disadvantages, they have certain limitations in production efficiency and cost control. As an emerging additive manufacturing technology, inkjet printing has shown good manufacturing potential, but it still faces challenges in high filling factor, flexible curvature control, and liquid confinement. Therefore, it is still necessary to develop a more efficient and precise method for manufacturing microlens arrays. Summary of the invention

[0005] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, the present invention provides a method for preparing a microlens array, which constructs a patterned hydrophilic-hydrophobic gradient on a substrate and forms a confined energy barrier at the hydrophilic-hydrophobic boundary to constrain the movement of the solid / liquid / gas three-phase contact line, thereby helping to improve the manufacturing accuracy, performance and reliability of the microlens array.

[0006] The invention also provides a microlens array.

[0007] The invention also provides a micro-optical system.

[0008] The invention also provides an electronic device.

[0009] The first aspect of the present invention provides a method for preparing a microlens array based on fluid confinement additive, including constructing a patterned hydrophilic-hydrophobic gradient on a substrate, forming a confined energy barrier at the hydrophilic-hydrophobic boundary to constrain the movement of the solid / liquid / gas three-phase contact line, and realizing the confinement of droplets.

[0010] A technical solution in the method for preparing a microlens array based on fluid confinement additive in the present invention has at least the following beneficial effects:

[0011] In the process of preparing microlens arrays, a patterned hydrophilic-hydrophobic gradient is constructed on the substrate, and a confined energy barrier is formed at the hydrophilic-hydrophobic boundary to constrain the movement of the solid / liquid / gas three-phase contact line, which can bring a series of beneficial effects. These effects help to improve the manufacturing accuracy, performance and reliability of microlens arrays. Specifically:

[0012] The accuracy of droplet positioning can be improved. The patterned hydrophilic-hydrophobic gradient can form a clear droplet boundary and contact line on the substrate. This boundary effectively limits the expansion and movement of the droplet and enhances the stability of the droplet. By precisely designing the hydrophilic-hydrophobic gradient, the position and shape of the droplet on the substrate can be more accurately controlled, thereby achieving higher manufacturing accuracy. Specifically, in the manufacture of microlens arrays, the shape and position of the droplet are crucial to the optical performance of the final lens. By constructing a hydrophilic-hydrophobic gradient on the substrate, a stable interface can be formed at the solid / liquid / gas three-phase contact line of the droplet. This interface helps to reduce the position drift and shape deformation of the droplet during the manufacturing process, thereby improving the positioning accuracy of the microlens.

[0013] The shape of the microlens is optimized. The confined energy barrier can affect the shape and curvature of the droplet. By precisely adjusting the hydrophilic-hydrophobic gradient, the curvature of the microlens can be finely controlled. While controlling the shape of the droplet, the gradient boundary helps reduce surface roughness and improve the smoothness of the microlens. Specifically, the optical properties of the microlens are directly affected by its surface shape and curvature. The patterned hydrophilic-hydrophobic gradient can precisely control the contraction and expansion of the droplet, thereby achieving precise curvature control of the microlens. This control can significantly improve the optical quality of the lens and optimize its performance in the optical system.

[0014] Improved manufacturing consistency. By creating a consistent hydrophilic-hydrophobic gradient, the consistency of each microlens during the manufacturing process can be guaranteed, reducing variability in batch production. The stability and consistency of the droplets help improve the stability of the entire manufacturing process, thereby reducing scrap rates and improving production efficiency. Specifically, a consistent hydrophilic-hydrophobic gradient can provide the same droplet contact conditions in each production, ensuring the consistency of the shape and optical properties of the microlenses. This is particularly important for large-scale production, as consistency directly affects the quality and performance of the product.

[0015] Improved manufacturing accuracy and efficiency. Patterned hydrophilic-hydrophobic gradients can reduce the need for secondary processing of droplets, thereby improving manufacturing efficiency. By precisely controlling the shape and position of droplets, material waste can be effectively reduced and production costs can be reduced. Specifically, in the preparation process of microlens arrays, precise control of the shape of droplets can reduce the need for subsequent processing steps. For example, reducing the trimming or adjustment of the droplet shape can improve the efficiency of the entire manufacturing process. In addition, optimizing the shape and position of droplets can also help reduce the waste of raw materials and reduce production costs.

[0016] It is possible to manufacture complex structures. By designing complex hydrophilic and hydrophobic gradients, microlens structures with different functions can be manufactured on the same substrate. This method provides greater design freedom, enabling innovative microlens structures and functions. Specifically, using patterned hydrophilic and hydrophobic gradients, complex microlens structure designs, such as different curvatures, sizes or functional areas, can be achieved on one substrate. This flexibility makes it possible to manufacture microlens arrays with specific optical properties to meet a wider range of application needs.

[0017] Therefore, the preparation method of the present invention can significantly improve the precision, performance and consistency of microlens array manufacturing by constructing a patterned hydrophilic-hydrophobic gradient on a substrate and using a confined energy barrier to constrain the movement of the solid / liquid / gas three-phase contact line. This method performs well in improving manufacturing efficiency, reducing material waste and realizing complex structural design, and is of great significance for the wide application of microlens arrays.

[0018] According to some embodiments of the present invention, the method of forming a confined energy barrier at a hydrophilic-hydrophobic boundary comprises a patterned vacuum ultraviolet light modification method or a photolithography method.

[0019] According to some embodiments of the present invention, the patterned vacuum ultraviolet light modification method comprises the following steps:

[0020] S1: coating a hydrophobic polymer on the surface of the substrate to form a hydrophobic polymer layer;

[0021] S2: The hydrophobic polymer layer is subjected to high-energy ultraviolet irradiation under a mask, and the surface of the hydrophobic polymer layer is patterned or etched, forming a wettability gradient and a geometric height difference at the boundary between the irradiated and non-irradiated areas, thereby constructing a chemical energy barrier and a geometric energy barrier that constrain the movement of the three-phase contact line.

[0022] According to some embodiments of the invention, the wavelength of the high energy ultraviolet radiation is less than 300 nm.

[0023] According to some embodiments of the invention, the wavelength of the high energy ultraviolet radiation is less than 255 nm.

[0024] According to some embodiments of the present invention, the wavelength of the high-energy ultraviolet radiation may be 172 nm.

[0025] According to some embodiments of the present invention, the exposure dose of the high energy ultraviolet radiation is 400 mJ / cm 2 ~800mJ / cm 2 .

[0026] According to some embodiments of the present invention, the exposure dose of the high energy ultraviolet radiation is 400 mJ / cm 2 、500mJ / cm 2 、600mJ / cm 2 、700mJ / cm 2 、800mJ / cm 2 Any value or a range formed by any two of them, such as 500mJ / cm 2 ~600mJ / cm 2 .

[0027] According to some embodiments of the present invention, the photolithography method comprises the following steps:

[0028] N1: coating a hydrophobic polymer on the surface of the substrate to form a hydrophobic polymer layer;

[0029] N2: coating the surface of the hydrophobic polymer layer with a photoresist to form a photoresist layer, and patterning the photoresist layer with a photolithography machine and then developing the patterned photoresist layer;

[0030] N3: After etching the exposed hydrophobic polymer layer by RIE, the photoresist layer is removed.

[0031] According to some embodiments of the invention, the hydrophobic polymer comprises Cytop, Hyflon or AF1600X.

[0032] According to some embodiments of the present invention, the thickness of the hydrophobic polymer layer is 600 nm to 1200 nm.

[0033] The hydrophobic polymer layer has the following typical characteristics: it is hydrophobic (the surface energy is much smaller than that of the substrate), and its main chain or main side chain functional groups may break or degrade under specific ultraviolet wavelengths; under the mask, it is irradiated with high-energy ultraviolet light to form a patterned modification or etching of the hydrophobic coating, thereby forming a wettability gradient and a geometric height difference at the boundary between the irradiated and unirradiated areas, thus constructing a chemical energy barrier and a geometric energy barrier to constrain the movement of the three-phase contact line.

[0034] Similarly, a layer of hydrophobic polymer is coated on the substrate material; on this basis, a layer of photoresist is coated; under the mask, the photoresist is irradiated with 365nm ultraviolet light to form a patterned etching to construct a "sacrificial layer"; the exposed hydrophobic coating is etched by RIE; the "sacrificial layer" is removed; thereby forming a wettability gradient and a geometric height difference, constructing a chemical energy barrier and a geometric energy barrier that constrain the movement of the three-phase contact line.

[0035] After that, after the patterned confined energy barrier is constructed, a photocurable fluid is added to the modified hydrophilic area through a precise additive method; the specific implementation methods can be: 1) Selective wetting: self-assembly of the added material in the confined area is completed by blade coating and roller coating. 2) Inkjet printing: a certain volume of the added material is dripped into the confined area by inkjet printing.

[0036] Finally, the microlens array is cured by ultraviolet light curing.

[0037] The present invention utilizes the surface tension of the added material to shape the microlens, and can realize a smooth lens curved surface. At the same time, by changing the modification strength or etching depth in the confinement process, and adjusting the volume of the added material, the curvature of a single microlens can be flexibly adjusted, and then the focal length of a single microlens can be autonomously and quickly tuned.

[0038] The second aspect of the present invention provides a microlens array, which is prepared by the preparation method of the first aspect of the present invention.

[0039] One of the technical solutions of the present invention regarding the microlens array has at least the following beneficial effects:

[0040] The optical performance of the microlens is optimized. The optical performance of the microlens is highly dependent on its curvature and surface shape. The patterned hydrophilic-hydrophobic gradient helps to precisely control the expansion and contraction of the droplets to achieve the desired lens curvature. This precise control can significantly improve the optical performance of the microlens, such as focusing ability, resolution, etc. The present invention can precisely adjust the curvature of the microlens by controlling the shape of the droplets. This is crucial for achieving high-quality optical imaging. Stable droplet shape and position help to improve the optical consistency of each lens in the microlens array and reduce differences in optical performance.

[0041] Higher manufacturing accuracy and consistency. The stability and precise positioning of droplets during the manufacturing process directly affect the quality and consistency of the microlenses. The use of patterned hydrophilic and hydrophobic gradients can ensure that the droplets exhibit the same behavior in each manufacturing, thereby improving the manufacturing accuracy and consistency of the entire microlens array. Through precise droplet positioning and shape control, the size and shape of the microlens can be strictly controlled, thereby improving manufacturing accuracy. The consistent hydrophilic and hydrophobic gradient constructed on the substrate ensures consistent droplet behavior in each manufacturing, ensuring high consistency of the microlens array.

[0042] The invention has higher production efficiency and lower cost. The microlens array of the invention can precisely control the shape and position of the droplets, reduce the excessive use of materials and the scrap rate, thereby reducing production costs. In addition, reducing the post-processing steps also means that the production process is more efficient, saving time and resources.

[0043] The microlens array of the present invention supports the realization of complex structures and functions. The patterned hydrophilic-hydrophobic gradient allows the manufacture of microlenses with multiple functions on the same substrate. This design flexibility makes it possible to develop microlens arrays with specific optical properties, such as multi-focal lenses or lens arrays with special optical properties, expanding the application field of microlenses.

[0044] The microlens array of the present invention has better surface smoothness and quality. The surface smoothness of the microlens directly affects its optical performance. The patterned hydrophilic-hydrophobic gradient helps to maintain the smooth shape of the droplet, thereby reducing surface defects that may occur during the manufacturing process and improving the smoothness and overall optical effect of the microlens.

[0045] A third aspect of the present invention provides a micro-optical system, comprising the microlens array according to the second aspect of the present invention.

[0046] In micro-optical systems, the use of microlens arrays based on patterned hydrophilic and hydrophobic gradients can significantly improve the performance and functionality of the system. Specifically:

[0047] Precisely controlled microlens curvature enables higher focusing capabilities, improving image clarity and resolution. Highly consistent microlens arrays ensure uniformity of optical performance, enabling the entire system to provide more consistent image quality.

[0048] The design flexibility of microlens arrays allows multiple optical functions to be implemented in one system, such as simultaneous image amplification, beam shaping, and optical adjustment. This flexibility enables the optical system to adapt to various application requirements, such as multifunctional displays in augmented reality (AR) or virtual reality (VR) systems. By manufacturing microlenses with multiple functions on the same substrate, a more compact and integrated optical system design can be achieved.

[0049] High-quality microlens arrays reduce optical losses and improve the light transmission rate and efficiency of the optical system. Precisely designed microlens arrays can effectively shape and adjust the light beam to improve the optical performance of the system.

[0050] In applications that require dynamic adjustment of optical parameters, microlens arrays can achieve optical adjustment, such as focus and beam adjustment, by adjusting the configuration of the lens. This method is more efficient and responsive than traditional mechanical adjustment, improving the flexibility and precision of the system. Some micro-optical systems use microlens arrays to achieve dynamic optical adjustment, such as autofocus and beam adjustment. The optical adjustment function of the microlens array can reduce dependence on mechanical adjustment and improve system reliability and response speed.

[0051] In applications that require compact space and light weight, such as portable devices and mobile devices, microlens arrays can provide a more compact design solution and reduce the size and weight of the system. This can improve the portability and ease of use of the device and adapt to various modern application requirements. The high integration and design flexibility of the microlens array enable the optical system to achieve a more compact design to adapt to space-constrained applications. Efficient micro-optical design reduces the number of optical components required for the system, thereby reducing the overall weight.

[0052] A fourth aspect of the present invention provides an electronic device, comprising the micro-optical system according to the third aspect of the present invention.

[0053] The application of microlens arrays containing patterned hydrophilic-hydrophobic gradients in electronic devices can significantly improve the display quality and functionality of the device. It can provide higher image resolution and clarity, achieve precise beam shaping and adjustment, and enhance the visual experience. In addition, the high consistency and manufacturing efficiency of this micro-optical system can also reduce the size and weight of the device, reduce production costs, and improve the overall performance and user experience of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a schematic diagram of the preparation process of the patterned vacuum ultraviolet light modification method of Example 1.

[0055] Figure 2 It is a schematic diagram of the photolithography preparation process of Example 2.

[0056] Figure 3 It is a schematic diagram of the cross-sectional structure of a microlens array. DETAILED DESCRIPTION

[0057] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0058] In the first aspect, some embodiments of the present invention provide a method for preparing a microlens array based on fluid confinement additive, including constructing a patterned hydrophilic-hydrophobic gradient on a substrate, forming a confined energy barrier at the hydrophilic-hydrophobic boundary to constrain the movement of the solid / liquid / gas three-phase contact line, and realizing the confinement of droplets.

[0059] It can be understood that in the process of preparing the microlens array, constructing a patterned hydrophilic-hydrophobic gradient on the substrate and forming a confined energy barrier at the hydrophilic-hydrophobic boundary to constrain the movement of the solid / liquid / gas three-phase contact line can bring a series of beneficial effects. These effects help to improve the manufacturing accuracy, performance and reliability of the microlens array. Specifically:

[0060] The accuracy of droplet positioning can be improved. The patterned hydrophilic-hydrophobic gradient can form a clear droplet boundary and contact line on the substrate. This boundary effectively limits the expansion and movement of the droplet and enhances the stability of the droplet. By precisely designing the hydrophilic-hydrophobic gradient, the position and shape of the droplet on the substrate can be more accurately controlled, thereby achieving higher manufacturing accuracy. Specifically, in the manufacture of microlens arrays, the shape and position of the droplet are crucial to the optical performance of the final lens. By constructing a hydrophilic-hydrophobic gradient on the substrate, a stable interface can be formed at the solid / liquid / gas three-phase contact line of the droplet. This interface helps to reduce the position drift and shape deformation of the droplet during the manufacturing process, thereby improving the positioning accuracy of the microlens.

[0061] The shape of the microlens is optimized. The confined energy barrier can affect the shape and curvature of the droplet. By precisely adjusting the hydrophilic-hydrophobic gradient, the curvature of the microlens can be finely controlled. While controlling the shape of the droplet, the gradient boundary helps reduce surface roughness and improve the smoothness of the microlens. Specifically, the optical properties of the microlens are directly affected by its surface shape and curvature. The patterned hydrophilic-hydrophobic gradient can precisely control the contraction and expansion of the droplet, thereby achieving precise curvature control of the microlens. This control can significantly improve the optical quality of the lens and optimize its performance in the optical system.

[0062] Improved manufacturing consistency. By creating a consistent hydrophilic-hydrophobic gradient, the consistency of each microlens during the manufacturing process can be guaranteed, reducing variability in batch production. The stability and consistency of the droplets help improve the stability of the entire manufacturing process, thereby reducing scrap rates and improving production efficiency. Specifically, a consistent hydrophilic-hydrophobic gradient can provide the same droplet contact conditions in each production, ensuring the consistency of the shape and optical properties of the microlenses. This is particularly important for large-scale production, as consistency directly affects the quality and performance of the product.

[0063] Improved manufacturing accuracy and efficiency. Patterned hydrophilic-hydrophobic gradients can reduce the need for secondary processing of droplets, thereby improving manufacturing efficiency. By precisely controlling the shape and position of droplets, material waste can be effectively reduced and production costs can be reduced. Specifically, in the preparation process of microlens arrays, precise control of the shape of droplets can reduce the need for subsequent processing steps. For example, reducing the trimming or adjustment of the droplet shape can improve the efficiency of the entire manufacturing process. In addition, optimizing the shape and position of droplets can also help reduce the waste of raw materials and reduce production costs.

[0064] It is possible to manufacture complex structures. By designing complex hydrophilic and hydrophobic gradients, microlens structures with different functions can be manufactured on the same substrate. This method provides greater design freedom, enabling innovative microlens structures and functions. Specifically, using patterned hydrophilic and hydrophobic gradients, complex microlens structure designs, such as different curvatures, sizes or functional areas, can be achieved on one substrate. This flexibility makes it possible to manufacture microlens arrays with specific optical properties to meet a wider range of application needs.

[0065] Therefore, the preparation method of the present invention can significantly improve the precision, performance and consistency of microlens array manufacturing by constructing a patterned hydrophilic-hydrophobic gradient on a substrate and using a confined energy barrier to constrain the movement of the solid / liquid / gas three-phase contact line. This method performs well in improving manufacturing efficiency, reducing material waste and realizing complex structural design, and is of great significance for the wide application of microlens arrays.

[0066] In combination with the second aspect, in some embodiments of the present invention, the method of forming a confined energy barrier at the hydrophilic-hydrophobic boundary includes a patterned vacuum ultraviolet light modification method or a photolithography method.

[0067] In conjunction with the second aspect, in some embodiments of the present invention, the patterned vacuum ultraviolet light modification method comprises the following steps:

[0068] S1: coating a hydrophobic polymer on the surface of the substrate to form a hydrophobic polymer layer;

[0069] S2: The hydrophobic polymer layer is exposed to high-energy ultraviolet light under a mask, and the surface of the hydrophobic polymer layer is patterned or etched, forming a wettability gradient and a geometric height difference at the boundary between the irradiated and non-irradiated areas, thereby constructing a chemical energy barrier and a geometric energy barrier that constrain the movement of the three-phase contact line.

[0070] In combination with the second aspect, in some embodiments of the present invention, the wavelength of the high-energy ultraviolet radiation is less than 300 nm.

[0071] In combination with the second aspect, in some embodiments of the present invention, the wavelength of the high-energy ultraviolet radiation is less than 255 nm.

[0072] In combination with the second aspect, in some embodiments of the present invention, the wavelength of the high-energy ultraviolet radiation can be 172 nm.

[0073] In combination with the second aspect, in some embodiments of the present invention, the exposure amount of high-energy ultraviolet radiation is 400mJ / cm 2 ~800mJ / cm 2 .

[0074] In combination with the second aspect, in some embodiments of the present invention, the exposure amount of high-energy ultraviolet radiation is 400mJ / cm 2 、500mJ / cm 2 、600mJ / cm 2 、700mJ / cm 2 、800mJ / cm 2 Any value or a range formed by any two of them, such as 500mJ / cm 2 ~600mJ / cm 2 .

[0075] It should be noted that the vacuum ultraviolet spectrum ranges from tens of nanometers to 200nm. According to the wave-particle duality principle and the wave equation, the shorter the wavelength, the higher the energy. For example, the intensity of 172nm ultraviolet light is greater than 10mW / cm 2 If the exposure is 1min, the exposure is greater than 600mJ / cm 2 .

[0076] In conjunction with the second aspect, in some embodiments of the present invention, the photolithography method includes the following steps:

[0077] N1: coating a hydrophobic polymer on the surface of the substrate to form a hydrophobic polymer layer;

[0078] N2: coating the surface of the hydrophobic polymer layer with a photoresist to form a photoresist layer, and patterning the photoresist layer with a photolithography machine and then developing the patterned photoresist layer;

[0079] N3: After etching the exposed hydrophobic polymer layer by RIE, the photoresist layer is removed.

[0080] In conjunction with the second aspect, in some embodiments of the present invention, the hydrophobic polymer includes Cytop, Hyflon or AF1600X.

[0081] In combination with the second aspect, in some embodiments of the present invention, the thickness of the hydrophobic polymer layer is 600 nm to 1200 nm.

[0082] The hydrophobic polymer layer has the following typical characteristics: it is hydrophobic (the surface energy is much smaller than that of the substrate), and its main chain or main side chain functional groups may break or degrade under specific ultraviolet wavelengths; under the mask, it is irradiated with high-energy ultraviolet light to form a patterned modification or etching of the hydrophobic coating, thereby forming a wettability gradient and a geometric height difference at the boundary between the irradiated and unirradiated areas, thus constructing a chemical energy barrier and a geometric energy barrier to constrain the movement of the three-phase contact line.

[0083] Similarly, a layer of hydrophobic polymer is coated on the substrate material; on this basis, a layer of photoresist is coated; under the mask, the photoresist is irradiated with 365nm ultraviolet light to form a patterned etching to construct a "sacrificial layer"; the exposed hydrophobic coating is etched by RIE; the "sacrificial layer" is removed; thereby forming a wettability gradient and a geometric height difference, constructing a chemical energy barrier and a geometric energy barrier that constrain the movement of the three-phase contact line.

[0084] After that, after the patterned confined energy barrier is constructed, a photocurable fluid is added to the modified hydrophilic area through a precise additive method; the specific implementation methods can be: 1) Selective wetting: self-assembly of the added material in the confined area is completed by blade coating and roller coating. 2) Inkjet printing: a certain volume of the added material is dripped into the confined area by inkjet printing.

[0085] Finally, the microlens array is cured by ultraviolet light curing.

[0086] The present invention utilizes the surface tension of the added material to shape the microlens, and can realize a smooth lens curved surface. At the same time, by changing the modification strength or etching depth in the confinement process, and adjusting the volume of the added material, the curvature of a single microlens can be flexibly adjusted, and then the focal length of a single microlens can be autonomously and quickly tuned.

[0087] In a second aspect, some embodiments of the present invention provide a microlens array prepared by the preparation method of the first aspect of the present invention.

[0088] The microlens array of the present invention optimizes the optical performance of the microlens. The optical performance of the microlens is highly dependent on its curvature and surface shape. The patterned hydrophilic-hydrophobic gradient helps to accurately control the expansion and contraction of the droplets, thereby achieving the desired lens curvature. This precise control can significantly improve the optical performance of the microlens, such as focusing ability, resolution, etc. The present invention can accurately adjust the curvature of the microlens by controlling the shape of the droplets. This is crucial for achieving high-quality optical imaging. Stable droplet shape and position help to improve the optical consistency of each lens in the microlens array and reduce differences in optical performance.

[0089] The microlens array of the present invention has higher manufacturing accuracy and consistency. The stability and precise positioning of the droplets during the manufacturing process directly affect the quality and consistency of the microlenses. The use of patterned hydrophilic and hydrophobic gradients can ensure that the droplets exhibit the same behavior in each manufacturing, thereby improving the manufacturing accuracy and consistency of the entire microlens array. Through precise droplet positioning and shape control, the size and shape of the microlens can be strictly controlled, thereby improving manufacturing accuracy. The consistent hydrophilic and hydrophobic gradients constructed on the substrate ensure that the droplets behave consistently in each manufacturing, ensuring the high consistency of the microlens array.

[0090] The microlens array of the present invention has higher production efficiency and lower cost. The microlens array of the present invention accurately controls the shape and position of the droplets, reduces the excessive use of materials and the scrap rate, thereby reducing production costs. In addition, reducing the post-processing steps also means that the production process is more efficient, saving time and resources.

[0091] The microlens array of the present invention supports the realization of complex structures and functions. The patterned hydrophilic-hydrophobic gradient allows the manufacture of microlenses with multiple functions on the same substrate. This design flexibility makes it possible to develop microlens arrays with specific optical properties, such as multi-focal lenses or lens arrays with special optical properties, expanding the application field of microlenses.

[0092] The microlens array of the present invention has better surface smoothness and quality. The surface smoothness of the microlens directly affects its optical performance. The patterned hydrophilic-hydrophobic gradient helps to maintain the smooth shape of the droplet, thereby reducing surface defects that may occur during the manufacturing process and improving the smoothness and overall optical effect of the microlens.

[0093] In a third aspect, some embodiments of the present invention provide a micro-optical system, wherein the micro-optical system comprises the microlens array according to the second aspect of the present invention.

[0094] It can be understood that precisely controlled microlens curvature can achieve higher focusing capabilities and improve image clarity and resolution. Highly consistent microlens arrays ensure uniformity of optical performance, enabling the entire system to provide more consistent image quality.

[0095] The design flexibility of microlens arrays allows multiple optical functions to be implemented in one system, such as simultaneous image amplification, beam shaping, and optical adjustment. This flexibility enables the optical system to adapt to various application requirements, such as multifunctional displays in augmented reality (AR) or virtual reality (VR) systems. By manufacturing microlenses with multiple functions on the same substrate, a more compact and integrated optical system design can be achieved.

[0096] High-quality microlens arrays reduce optical losses and improve the light transmission rate and efficiency of the optical system. Precisely designed microlens arrays can effectively shape and adjust the light beam to improve the optical performance of the system.

[0097] In applications that require dynamic adjustment of optical parameters, microlens arrays can achieve optical adjustment, such as focus and beam adjustment, by adjusting the configuration of the lens. This method is more efficient and responsive than traditional mechanical adjustment, improving the flexibility and precision of the system. Some micro-optical systems use microlens arrays to achieve dynamic optical adjustment, such as autofocus and beam adjustment. The optical adjustment function of the microlens array can reduce dependence on mechanical adjustment and improve system reliability and response speed.

[0098] In applications that require compact space and light weight, such as portable devices and mobile devices, microlens arrays can provide a more compact design solution and reduce the size and weight of the system. This can improve the portability and ease of use of the device and adapt to various modern application requirements. The high integration and design flexibility of the microlens array enable the optical system to achieve a more compact design to adapt to space-constrained applications. Efficient micro-optical design reduces the number of optical components required for the system, thereby reducing the overall weight.

[0099] In a fourth aspect, some embodiments of the present invention provide an electronic device, wherein the electronic device comprises the micro-optical system according to the third aspect of the present invention.

[0100] The application of microlens arrays containing patterned hydrophilic-hydrophobic gradients in electronic devices can significantly improve the display quality and functionality of the device. It can provide higher image resolution and clarity, achieve precise beam shaping and adjustment, and enhance the visual experience. In addition, the high consistency and manufacturing efficiency of this micro-optical system can also reduce the size and weight of the device, reduce production costs, and improve the overall performance and user experience of the device.

[0101] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0102] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0103] Unless otherwise specified, "room temperature" in the present invention means 25°C±5°C.

[0104] Unless otherwise specified, "about" in the present invention means that the allowable error is within ±2%.

[0105] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0106] The present invention has been described in detail above in conjunction with the embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

[0107] Example 1

[0108] A microlens array was prepared, and the process was as follows Figure 1 As shown, the specific process is:

[0109] In the first step, a fluorine-containing polymer material Cytop was spin-coated on a clean glass substrate at a speed of 2000 rpm. After pre-curing at 130°C and main curing at 200°C, a 1000 nm uniform hydrophobic layer was covered on the glass substrate.

[0110] The second step is to use a vacuum ultraviolet lithography machine with a customized mask to pattern the hydrophobic layer. Since the main chain or main side chain functional groups of the fluorinated polymer break and degrade under a specific ultraviolet wavelength, the surface modification of the irradiated area is achieved. At the same time, the high-energy ultraviolet light etches the hydrophobic layer in the irradiated area to a certain depth. As a result, a wettability gradient and a geometric height difference are formed at the boundary between the irradiated and unirradiated areas.

[0111] In this embodiment, a 172nm vacuum ultraviolet lithography machine is used to pattern modify / etch the Cytop hydrophobic layer. The etching rate can reach 10.5nm / min, the modification / etching takes 9min, and the wetting angle difference of 2μL water can reach 37.6°.

[0112] Example 2

[0113] A microlens array was prepared, and the process was as follows Figure 2 As shown, the specific process is:

[0114] In the first step, a fluorine-containing polymer material Hyflon is spin-coated on a clean glass substrate at a rotation speed of 335 rpm. After pre-curing at 85°C and main curing at 180°C, a uniform hydrophobic layer thin film with a thickness of 800 nm is covered on the glass substrate.

[0115] In the second step, photoresist SUN1170P is spin-coated on the hydrophobic layer at a rotation speed of 3000 rpm, and then pre-cured at 110°C.

[0116] The third step is to use a 365nm UV lithography machine with a customized mask to pattern the photoresist. Then, a 1wt% KOH solution is prepared for development.

[0117] The fourth step is to use a reactive plasma etcher to etch the exposed hydrophobic area.

[0118] Step 5: Prepare 1 wt% KOH solution to remove the photoresist layer, thereby constructing a patterned hydrophilic and hydrophobic difference.

[0119] In this embodiment, the patterned exposed Hyflon is etched using a RIE etcher, the etching rate can reach 6.78 nm / min, and the wetting angle difference of 2 μL of water can reach 89.8°.

[0120] Figure 3 It is a cross-sectional view of the microlens array structure prepared in Example 1 and Example 2. Figure 3 In the figure, 1 is a patterned hydrophobic layer, 2 is an added material, and 3 is a glass substrate.

[0121] The method for preparing the microlens array of the present invention can be applied to the manufacture of large-area microlens arrays, and further applied to multiple fields such as biomedicine, photographic imaging, and virtual reality technology.

Claims

1. A method for preparing a microlens array based on fluid confinement additive, characterized in that: The method includes constructing a patterned hydrophilic-hydrophobic gradient on a substrate, forming a confined energy barrier at the hydrophilic-hydrophobic boundary to constrain the movement of the solid / liquid / gas three-phase contact line, and realizing the confinement of droplets.

2. The preparation method according to claim 1, characterized in that: Methods for forming a confined energy barrier at the hydrophilic-hydrophobic boundary include patterned vacuum ultraviolet light modification or photolithography.

3. The preparation method according to claim 2, characterized in that: The patterned vacuum ultraviolet light modification method includes the following steps: S1: coating a hydrophobic polymer on the surface of the substrate to form a hydrophobic polymer layer; S2: The hydrophobic polymer layer is subjected to high-energy ultraviolet irradiation under a mask, and the surface of the hydrophobic polymer layer is patterned or etched, forming a wettability gradient and a geometric height difference at the boundary between the irradiated and non-irradiated areas, thereby constructing a chemical energy barrier and a geometric energy barrier that constrain the movement of the three-phase contact line.

4. The preparation method according to claim 3, characterized in that: The wavelength of the high-energy ultraviolet radiation is less than 300nm; and / or the exposure amount of the high-energy ultraviolet radiation is 400mJ / cm 2 ~800mJ / cm 2 .

5. The preparation method according to claim 2, characterized in that: The photolithography method comprises the following steps: N1: coating a hydrophobic polymer on the surface of the substrate to form a hydrophobic polymer layer; N2: coating the surface of the hydrophobic polymer layer with a photoresist to form a photoresist layer, and patterning the photoresist layer with a photolithography machine and then developing the patterned photoresist layer; N3: After etching the exposed hydrophobic polymer layer by RIE, the photoresist layer is removed.

6. The preparation method according to claim 3 or 5, characterized in that: The hydrophobic polymer includes Cytop, Hyflon or AF1600X.

7. The preparation method according to claim 3 or 5, characterized in that: The thickness of the hydrophobic polymer layer is 600nm-1200nm.

8. A microlens array, characterized in that: The method is prepared according to any one of claims 1 to 7.

9. A micro-optical system, characterized in that: The micro-optical system comprises the micro-lens array as claimed in claim 8.

10. An electronic device, characterized in that: The electronic device comprises the micro-optical system according to claim 9.

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