CN107718611B - One kind being based on 3D printing and the formed in mould bionic compound eyes preparation method of negative pressure - Google Patents

Abstract

The invention provides a bionic compound eye preparation method based on 3D printing and negative pressure mold molding. The compound eye mold injection molding processing method with relatively simple equipment and raw materials is adopted to produce curved bionic compound eyes, and the cost of equipment and raw materials is relatively low. The improvement of the method can change the position of the silicone flexible film in the compound eye mold corresponding to the microlens mold hole by using a curved microhole array template with different microlens mold hole diameters and changing the negative pressure vacuum of the isolation space layer in the compound eye mold. The depth and curvature of the concave surface under the action of negative pressure can adjust the curvature of the microlens of the curved bionic compound eye produced by injection molding. The preparation and processing accuracy of the invention effectively solves the problem that the convenience and low cost of producing bionic compound eye products with different microlens curvatures are difficult to balance in the prior art.

Description

A bionic compound eye preparation method based on 3D printing and negative pressure mold forming

technical field

The invention relates to the technical field of bionic optics, in particular to a technology for preparing curved bionic compound eyes, in particular to a bionic compound eye preparation method based on 3D printing and negative pressure mold forming.

Background technique

Inspired by the main visual organs of insects in nature, bionic compound eyes have received extensive attention in the field of micro-optics. Because of their small size, large field of view and high sensitivity, they are an important part of micro-optical mechatronics systems. Compound eyes are composed of a large number of ommatidium, but their volume is on the order of micrometers, and each ommatidium has an independent light-sensing ability. Although its resolution is not high compared to the human eye, the compound eye usually has a field of view far beyond that of the human eye, the largest being close to 180°, which provides the possibility for the preparation of panoramic cameras. In addition, compound eyes have high sensitivity to moving objects, and flies in daily life can easily avoid our attacks by virtue of this feature. The research results of bionic compound eyes have been widely used in military, civil and medical fields, and have many potential application fields.

At present, the processing methods of bionic compound eyes mainly include direct processing method and film injection method. Commonly used direct processing methods mainly include ultra-precision engraving processing methods, soft lithography methods, laser direct writing methods, etc. The advantage of such methods is that the curvature of the microlenses on the bionic compound eye can be easily adjusted and designed according to needs, so that the microlenses can achieve However, these processing methods have problems such as long processing cycle, expensive equipment and complicated process. The film injection method is to first make a bionic compound eye processing mold, and then use a photosensitive polymer for injection molding and curing, and then demould and take out to obtain a bionic compound eye product. However, after the bionic compound eye processing mold is formed, the shape and curvature of the microlenses on the bionic compound eye are correspondingly fixed by the mold. To produce bionic compound eyes with different microlens curvatures, the corresponding processing molds need to be remade, so it is difficult to achieve Flexible adjustment and processing of microlens curvature in bionic compound eye products. This leads to the contradiction between the convenience and low cost of producing bionic compound eye products with different microlens curvatures in the current processing technology. In many different application scenarios, bionic compound eyes with different microlens curvatures and focal lengths are often required. product. Therefore, how to conveniently and flexibly produce a variety of bionic compound eye products with different microlens curvatures using a lower-cost solution has become an important technical research direction in the field.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a bionic compound eye preparation method based on 3D printing and negative pressure mold molding, which adopts the compound eye mold injection molding processing method with relatively simple equipment and raw materials to produce curved bionic compound eyes, And by improving the structure of the compound eye mold, it is possible to adjust the microstructure of the curved bionic compound eye produced by injection molding by using the curved micropore array template with different diameters of the microlens mold hole and changing the negative pressure vacuum of the isolation space layer in the compound eye mold. Therefore, the technical goal of low-cost production of bionic compound eye products with different microlens curvatures is achieved, and the problem of difficulty in combining convenience and low cost of producing bionic compound eye products with different microlens curvatures in the prior art is solved.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

A bionic compound eye preparation method based on 3D printing and negative pressure mold forming, comprising the following steps:

1) 3D printing technology is used to prepare a curved microporous array template. The curved microporous array template is in the shape of a spherical cap as a whole, and there are several arranged and distributed on the curved microporous array template according to the preset density of compound eye arrays. Through the micro lens mold hole;

2) A flexible silicone film is prepared by curing liquid silicone, and the overall size of the flexible silicone film matches the concave side of the curved microporous array template;

3) Constructing a compound eye mold, the compound eye mold is composed of a mold box device, the curved microporous array template and the organic silicon flexible film combination;

The mold box device includes a box body and a box cover, the box body has a hollow cavity with an upper end open, and the peripheral side of the curved microporous array template is sealed and fixedly installed on the side of the hollow cavity of the box body on the wall, and the spherical cap-shaped top of the curved microwell array template is set downward, so that the curved microwell array template divides the hollow chamber of the box into two parts, an upper open space layer and a lower isolated space layer; The silicone flexible film is attached and laid on the concave side of the curved microporous array template, and seals and covers each microlens mold hole on the curved microporous array template, so that the isolation space layer becomes a closed space, And the box body device is also provided with a vacuum pump connected to the isolation space layer of the box body to vacuumize the isolation space layer; the closed cover of the box cover is closed on the upper end opening of the box body, and the bottom surface of the box cover is closed. It is spherical. When the box cover is closed on the box body, its spherical lower bottom surface and the concave side surface of the curved microporous array template are in a concentric setting state, and the lower bottom surface of the box cover is attached to the curved surface micropore. There is a gap between the silicone flexible films on the concave side of the hole array template, so that the lower bottom surface of the box cover and the silicone flexible film are spaced to form an injection molding cavity space, and the box cover is provided with ventilation through holes and a microfluidic injection channel, the gas permeable through hole and the microfluidic injection channel are respectively connected to two opposite positions of the space edge of the injection molding chamber, and the microfluidic injection channel is communicated with a microfluidic injection pump via a capillary;

4) Start the vacuum pump of the compound eye mold to evacuate the isolation space layer, and after the set vacuum degree is reached in the isolation space layer of the compound eye mold, fill the space of the injection molding cavity of the compound eye mold with photosensitive materials through a micro-flow injection pump. After curing, the polymer is demolded and taken out to obtain a curved bionic compound eye.

In the above-mentioned bionic compound eye preparation method based on 3D printing and negative pressure mold forming, as a preferred solution, the curved microporous array template is prepared by a 3D printing stereolithography method.

In the above bionic compound eye preparation method based on 3D printing and negative pressure mold forming, as a preferred solution, the liquid silicone used in the step 2) is liquid polydimethylsiloxane, and a curing agent is added. The addition amount is 10% to 15% of the mass of the polydimethylsiloxane, and the organosilicon flexible film thus prepared is a polydimethylsiloxane flexible film.

In the above-mentioned bionic compound eye preparation method based on 3D printing and negative pressure mold forming, as a preferred solution, the spin coating method is used to prepare the polydimethylsiloxane flexible film, and the rotational speed of the spin coater is controlled to be 300-1000 rpm, and heating is performed. For curing, the heating temperature is 60-80° C. and the heating time is 50-70 min, and a polydimethylsiloxane flexible film with a thickness of 80-150 μm is prepared.

In the above bionic compound eye preparation method based on 3D printing and negative pressure mold forming, as a further preferred solution, after the polydimethylsiloxane flexible film is obtained by the spin coating method, it is first soaked in anhydrous alcohol for 20-30 minutes, and then the polydimethylsiloxane is soaked for 20-30 minutes. The flexible film of dimethylsiloxane was peeled from the spin coater.

In the above-mentioned bionic compound eye preparation method based on 3D printing and negative pressure mold forming, as a preferred solution, the box cover in the mold box device is made of liquid silicone through mold injection.

In the above-mentioned bionic compound eye preparation method based on 3D printing and negative pressure mold molding, as a preferred solution, in the step 4), the injection rate of filling the photosensitive polymer into the injection molding cavity of the compound eye mold through a microfluidic injection pump is 80 ℃. ~150 μL/min.

In the above bionic compound eye preparation method based on 3D printing and negative pressure mold forming, as a preferred solution, the photosensitive polymer used in the step 4) is UV-curable photosensitive adhesive NOA81.

In the above-mentioned bionic compound eye preparation method based on 3D printing and negative pressure mold molding, as a further preferred solution, after the injection cavity space of the compound eye mold is filled with UV-curable photosensitive adhesive NOA81 through a microfluidic injection pump, the specific curing process is as follows: The method is: put the compound eye mold into the ultraviolet light equipment for ultraviolet light curing, the ultraviolet light exposure power is 200~400W, and the exposure time is 1~2min, so that the ultraviolet curing photosensitive adhesive NOA81 is cured.

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

1. The present invention is based on a bionic compound eye preparation method based on 3D printing and negative pressure mold molding, and adopts a compound eye mold injection molding process with relatively simple equipment and raw materials to produce curved bionic compound eyes. The cost of equipment and raw materials is relatively low. , it is possible to change the position of the silicone flexible film in the compound eye mold corresponding to the position of the microlens mold hole by using a curved microhole array template with different microlens mold hole diameters and changing the negative pressure vacuum of the isolation space layer in the compound eye mold. Under the action of negative pressure, the concave depth and curvature can be adjusted to adjust the microlens curvature of the curved bionic compound eye produced by injection molding, and the technical goal of producing bionic compound eye products with different microlens curvatures at low cost is achieved.

2. The bionic compound eye preparation method based on 3D printing and negative pressure mold molding of the present invention has the advantages of simple operation in the preparation process, short preparation and processing cycle, and flexible adjustment of the diameter of the microlens die holes and the isolation space layer of the used curved micropore array template. The vacuum degree of negative pressure is high, and the scalability is strong.

3. In the bionic compound eye preparation method based on 3D printing and negative pressure mold forming of the present invention, the curved microporous array template is prepared by 3D printing technology, which can well ensure the processing precision, thereby ensuring the preparation and processing precision of the bionic compound eye product.

4. The bionic compound eye preparation method of the present invention is based on 3D printing and negative pressure mold molding. Excessive injection through the microfluidic injection channel can effectively exhaust gas and prevent the influence of possible impurities; using NOA81 as the molding material has good optical properties and can be used in The curing is completed in 1~2min, which not only shortens the process cycle, but also protects the lithography equipment more effectively.

Description of drawings

FIG. 1 is a flow chart of a method for preparing a multifocal bionic compound eye based on 3D printing of the present invention.

FIG. 2 is a schematic structural diagram of the compound eye mold used in the method of the present invention.

FIG. 3 is a physical diagram of three different curved bionic compound eye products prepared in the embodiment of the present invention and a curved microporous array template prepared by 3D printing technology.

Detailed ways

The present invention provides a bionic compound eye preparation method of 3D printing and negative pressure mold forming, the process of which is shown in FIG. 1 and includes the following steps:

1) 3D printing technology is used to prepare a curved microporous array template. The curved microporous array template is in the shape of a spherical cap as a whole, and there are several arranged and distributed on the curved microporous array template according to the preset density of compound eye arrays. A through-hole microlens die hole.

The curved micropore array template prepared in this step is used as a structural component of a compound eye mold. The micro-lens die holes on the curved micro-hole array template are arranged and designed according to the preset density of the compound eye array, which is used to locate the position of the micro-lens on the bionic compound eye of the curved surface. Therefore, the diameter of the micro-lens die hole can be adjusted according to the surface bionic The processing requirements of the microlens size on the compound eye are designed. In order to better ensure the preparation and processing accuracy of the curved micro-hole array template, it is best to use the 3D printing stereo light curing method to prepare, and the 3D printing processing accuracy error can reach below 30 μm, which can well ensure the processing accuracy. For different production goals, multiple curved micro-hole array templates with different diameters of micro-lens die holes can be prepared for future use.

2) A flexible silicone film is prepared by curing liquid silicone, and the overall size of the flexible silicone film matches the concave side of the curved microporous array template.

The silicone flexible film prepared in this step is also used as a structural component of a compound eye mold. The liquid silicone used in the preparation can be made of common silicone materials; but as a preferred solution, it is best to use liquid polydimethylsiloxane as the liquid silicone material for preparing the silicone flexible film, and in order to facilitate curing and processing, it is best to use liquid polydimethylsiloxane. A curing agent is added in it, and the amount of the curing agent is 10% to 15% of the mass of the polydimethylsiloxane. The silicone flexible film thus prepared is the polydimethylsiloxane flexible film, which has Good elasticity and toughness. It is best to use the spin coating method when preparing the polydimethylsiloxane flexible film, which can better control the thickness of the obtained polydimethylsiloxane flexible film; when preparing, control the rotation speed of the spin coater to be 300~1000rpm , and heating and curing, the heating temperature is 60-80 °C, and the heating time is 50-70 min, to prepare a polydimethylsiloxane flexible film with a thickness of 80-150 μm. With the help of the elasticity and toughness of polydimethylsiloxane materials, a flexible polydimethylsiloxane film with a thickness of 80-150 μm was prepared by spin coating method, which can make it better match with the curved microporous array template. The microlens injection mold cavity is formed under negative pressure; if the thickness of the polydimethylsiloxane flexible film is too thick, it is easy to cause its deformation degree under negative pressure to be limited and it is difficult to form a microlens injection mold cavity that meets the requirements; If the thickness of the polydimethylsiloxane flexible film is too thin, it is easy to cause excessive deformation and rupture under negative pressure. After the polydimethylsiloxane flexible film is obtained by spin coating, it is best to soak it in anhydrous alcohol for 20~30min, and then peel off the polydimethylsiloxane flexible film from the silicon substrate, which is more helpful. To prevent the polydimethylsiloxane flexible film from being broken and damaged when it is peeled off from the silicon substrate. Since a flexible silicone film needs to be replaced after each curved bionic compound eye is produced, as a consumable part, multiple flexible silicone films can be prepared for future use; in specific preparation, liquid polydimethylsiloxane can be used for A large size (for example, 4-8 inches) silicone flexible film material layer is prepared by spin coating, and then multiple silicone flexible films are obtained by cutting on the silicone flexible film material layer.

3) Constructing a compound eye mold, the compound eye mold is composed of a mold box device, a combination of the curved microporous array template and the silicone flexible film prepared previously.

The structure of the compound eye mold is shown in Figure 2. The components of the compound eye mold include a mold box device 10, a curved microporous array template 20 and a silicone flexible film 30; wherein, the mold box device 10 is pre-prepared for molding, which includes a box body 11 and a box cover 12, The box body 11 has a hollow chamber with an open upper end, the peripheral side of the curved microwell array template 20 is sealed and fixedly installed on the side wall of the hollow chamber of the box body 1, and the spherical cap-shaped top of the curved microwell array template 20 is sealed. It is set downward (that is, the concave side of the curved microwell array template is set up and the convex side is set downward), so that the hollow chamber of the box 1 is divided into the upper open space layer and the lower isolation layer by the curved microwell array template 20 There are two parts of the space layer 13; the silicone flexible film 30 is attached and laid on the concave side of the curved microporous array template 20, and each microlens mold hole 21 on the curved microporous array template 20 is sealed and covered, so that the space is isolated The layer 13 becomes a closed space, and the box body 11 is also provided with a vacuum pump 40 connected to the isolation space layer of the box body to evacuate the isolation space layer 13; the closed cover of the box cover 12 is closed on the upper end opening of the box body 11 Above, the lower bottom surface of the box cover 12 is spherical. When the box cover 12 is closed on the box body, its spherical lower bottom surface and the concave side surface of the curved microporous array template 20 are in a concentric setting state, and the box cover There is a gap between the lower bottom surface of 12 and the silicone flexible film 30 attached to the concave side of the curved microwell array template, so that the space between the lower bottom surface of the box cover 12 and the silicone flexible film 30 forms an injection molding cavity The chamber space 14, the box cover 12 is also provided with a ventilation through hole 15 and a microfluidic injection channel 16, and the ventilation through hole 15 and the microfluidic injection channel 16 are respectively connected to two opposite positions on the edge of the injection molding cavity space 14, and The microfluidic injection channel 16 communicates with a microfluidic injection pump 50 via capillaries.

In the compound eye mold thus constructed, it can be seen that when the mold box device is put into the box and the lid is closed on the upper end opening of the box, the curved microporous array template and its concave side are attached to the silicone flexible film. The hollow cavity inside the mold box device is divided into two space areas, the isolation space layer and the injection molding cavity space, and the isolation space layer below is sealed. The ventilation through holes on the box cover communicate with the external atmospheric pressure, so that the isolation space layer can be evacuated by a vacuum pump to form a negative pressure, so that the silicone flexible film attached to the concave side of the curved microporous array template corresponds to the microlens. The position of the mold hole is depressed downward by the negative pressure of the isolation space layer to form a microlens-type injection molding cavity, and the vacuum degree of the negative pressure formed by evacuating the isolation space layer is different, and the silicone flexible film corresponds to the microlens. The depth and curvature of the concave under the action of the negative pressure at the position of the die hole will also be different.

In the compound eye mold, the box cover of the mold box is also one of the important components that constitute the space of the injection molding cavity. In order to ensure the machining accuracy, the box cover in the mold box is preferably made of liquid silicone through mold injection. The microfluidic injection channel on the box cover is a micropipe with an inner diameter of less than 1000μm; while the microfluidic injection pump (also called a microinjection pump) refers to the use of micropipes (with an inner diameter of 10~1000μm) to control the fluid precisely, trace amounts, and uniformity. , Continuous output pump force instrument, which can control the fluid feed rate in milliliters per hour, the maximum is 99.9ml/h, and the minimum is 0.1ml/h. The use of microfluidic injection channel structure and microfluidic injection pump in the compound eye mold is to more accurately control the injection amount of photosensitive polymer into the injection molding cavity space to prepare the curved bionic compound eye, which helps to better avoid preparation The presence of air bubbles or magazines in the curved bionic compound eye affects the preparation quality.

4) Start the vacuum pump of the compound eye mold to evacuate the isolation space layer, and after the set vacuum degree is reached in the isolation space layer of the compound eye mold, fill the space of the injection molding cavity of the compound eye mold with photosensitive materials through a micro-flow injection pump. After curing, the polymer is demolded and taken out to obtain a curved bionic compound eye.

This step is used for preparing a curved bionic compound eye by injecting glue into a compound eye mold and demoulding. Among them, the photosensitive polymer used can choose UV-curable photosensitive adhesive NOA81 or other types of UV-curable photosensitive adhesive, and at the same time, the injection rate at which the photosensitive polymer is filled into the injection cavity of the compound eye mold through the microfluidic injection pump is preferably controlled as 80~150μL/min, and it is best to over-inject to ensure that the bubbles or impurities that may exist in the injection molding chamber are discharged; In order to speed up the curing and shorten the production cycle, for the UV-curable photosensitive adhesive NOA81, the following UV-curing treatment method can be used: put the compound eye mold into the UV-light equipment for UV-curing, the UV-light exposure power is 200~400W, and the exposure The time is 1~2min, so that the UV-curable photosensitive adhesive NOA81 is cured.

It can be seen from the above process that the bionic compound eye preparation method of the present invention based on 3D printing and negative pressure mold molding adopts the compound eye mold injection molding processing method with relatively simple equipment and raw materials to produce curved bionic compound eyes, and the compound eye mold structure is improved due to the improvement of the compound eye mold structure. , through the combination of the mold box device structure with the silicone flexible film and the curved microporous array template, it is possible to vacuum the isolation space layer of the compound eye mold by a vacuum pump, so that the concave surface of the curved microporous array template is attached to the surface of the organic microporous array template. The position of the silicon flexible film corresponding to the microlens die hole is depressed downward by the negative pressure of the isolation space layer to form a microlens-type injection molding cavity; if the diameter of the microlens die hole on the curved micropore array template is used, set the diameter of the microlens die hole. Different, the vacuum degree of vacuuming the isolation space layer to form negative pressure is different, the depth and curvature of the concave depression of the silicone flexible film corresponding to the position of the micro-lens mold hole under the action of negative pressure will also be different, which can make the injection mold cavity The curvature and focal length of the microlenses on the curved bionic compound eye obtained by injecting glue in the chamber space are also different accordingly; therefore, when the bionic compound eye is prepared by the method of the present invention, a plurality of curved microholes with different diameters of the microlens die holes can be prepared first Array template and multiple silicone flexible films, each time a curved biomimetic compound eye needs to be replaced with a new silicone flexible film, if the curved biomimetic compound eye with the same microlens curvature needs to be produced, the same microlens should be used in the compound eye mold The surface micro-hole array template with the diameter of the die hole can be evacuated to the same vacuum degree by controlling the vacuum pump to the isolation space layer of the compound eye mold before injection molding. If it is necessary to produce curved bionic compound eyes with different microlens curvatures, the corresponding It can be achieved by replacing the curved micro-hole array template with different micro-lens hole diameters in the compound eye mold and adjusting the vacuum degree of the vacuum pump to the isolation space layer of the compound eye mold, so that the curved bionic compound eye can be flexibly adjusted for production. The purpose of microlens curvature and focal length, thus realizing the technical goal of low-cost production of bionic compound eye products with different microlens curvatures, and solving the difficulty of convenience and low cost in producing bionic compound eye products with different microlens curvatures in the prior art issues of balance.

The method of the present invention will be described below with embodiments. It should be understood that these embodiments are only used to further illustrate the embodiments of the present invention, not to limit the present invention.

Example:

The present embodiment adopts the method of the present invention to prepare curved bionic compound eyes, and the preparation process is as follows:

1) 3D printing technology is used to prepare the curved microwell array template. The curved microwell array template is in the shape of a spherical cap as a whole, and several through holes are arranged on the curved microwell array template according to the preset compound eye array arrangement density. Microlens die hole.

In this example, 3D printing technology was used to prepare seven curved micro-hole array templates with different diameters of micro-lens die holes, and the diameters of their respective micro-lens die holes were 600 μm, 800 μm, 1000 μm, 1200 μm, 1400 μm, 1600 μm, and 1800 μm, respectively.

2) A flexible silicone film is prepared by curing liquid silicone, and the overall size of the flexible silicone film matches the concave side of the curved microporous array template.

In this example, a plurality of polydimethylsiloxane flexible films (silicon flexible films) were prepared by using liquid polydimethylsiloxane added with a curing agent. The influence of vacuum negative pressure conditions on the curvature of the microlens of the prepared curved bionic compound eye, the thickness of the polydimethylsiloxane flexible film prepared under unified control in this example is all 100 μm.

3) A compound eye mold as shown in Figure 2 was constructed by using a combination of a mold box device, a curved microporous array template and a silicone flexible film.

4) Start the vacuum pump of the compound eye mold to evacuate the isolation space layer, and after the set vacuum degree is reached in the isolation space layer of the compound eye mold, fill the space of the injection molding cavity of the compound eye mold with photosensitive materials through a micro-flow injection pump. After curing, the polymer is demolded and taken out to obtain a curved bionic compound eye.

In this embodiment, the above-mentioned steps 3) to 4) are repeated seven times to prepare seven curved bionic compound eyes. The seven preparation process uses the above seven curved microhole array templates with different diameters of the microlens mold holes to construct compound eye molds, and respectively Control the vacuum pump to evacuate the isolation space layer to achieve different degrees of vacuum, and then measure the convex height and curvature radius of the microlens of the obtained curved bionic compound eye after curing and demoulding. The data obtained are shown in Table 1.

Table 1

It can be seen that among the seven curved bionic compound eyes prepared above, due to the different diameters and sizes of the microlens mold holes on the curved micropore array template used, and the different vacuum degrees of vacuuming the isolation space layer to form a negative pressure, the silicone The concave depth and curvature of the flexible film corresponding to the position of the microlens mold hole under the action of negative pressure will also be different. Therefore, the convex height and curvature radius of the microlens of the prepared curved bionic compound eye are also different, resulting in seven microlenses. A curved bionic compound eye product with different lens curvatures and focal lengths. Fig. 3 shows 3 different curved bionic compound eye products prepared by the method of the present invention (as shown by the numbers ①, ②, ③ in Fig. 3) and a curved micropore array template prepared by 3D printing technology (as shown in Fig. 3 shown in No. ④). It is also confirmed that the method of the present invention can produce bionic compound eye products with different curvatures of microlenses in a low-cost and convenient manner.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be Modifications or equivalent substitutions without departing from the spirit and scope of the technical solutions of the present invention should be included in the scope of the claims of the present invention.

Claims (8)

1. a bionic compound eye preparation method based on 3D printing and negative pressure mould forming, is characterized in that, comprises the steps: 1) 3D printing technology is used to prepare a curved microporous array template. The curved microporous array template is in the shape of a spherical cap as a whole, and there are several arranged and distributed on the curved microporous array template according to the preset density of compound eye arrays. A through-hole micro-lens mold hole; the curved micro-hole array template is prepared by a 3D printing stereo light curing molding method; 2) A flexible silicone film is prepared by curing liquid silicone, and the overall size of the flexible silicone film matches the concave side of the curved microporous array template; 3) Constructing a compound eye mold, the compound eye mold is composed of a mold box device, the curved microporous array template and the organic silicon flexible film combination; The mold box device includes a box body and a box cover, the box body has a hollow cavity with an upper end open, and the peripheral side of the curved microporous array template is sealed and fixedly installed on the side of the hollow cavity of the box body on the wall, and the spherical cap-shaped top of the curved microwell array template is set downward, so that the curved microwell array template divides the hollow chamber of the box into two parts, an upper open space layer and a lower isolated space layer; The silicone flexible film is attached and laid on the concave side of the curved microporous array template, and seals and covers each microlens mold hole on the curved microporous array template, so that the isolation space layer becomes a closed space, And the box body device is also provided with a vacuum pump connected to the isolation space layer of the box body to vacuumize the isolation space layer; the closed cover of the box cover is closed on the upper end opening of the box body, and the bottom surface of the box cover is closed. It is spherical. When the box cover is closed on the box body, its spherical lower bottom surface and the concave side surface of the curved microporous array template are in a concentric setting state, and the lower bottom surface of the box cover is attached to the curved surface micropore. There is a gap between the silicone flexible films on the concave side of the hole array template, so that the lower bottom surface of the box cover and the silicone flexible film are spaced to form an injection molding cavity space, and the box cover is provided with ventilation through holes and a microfluidic injection channel, the gas permeable through hole and the microfluidic injection channel are respectively connected to two opposite positions of the space edge of the injection molding chamber, and the microfluidic injection channel is communicated with a microfluidic injection pump via a capillary; 4) Start the vacuum pump of the compound eye mold to evacuate the isolation space layer, so that the position of the silicone flexible film attached to the concave side of the curved microporous array template corresponding to the microlens mold hole is subjected to the negative pressure of the isolation space layer The micro-lens type injection molding cavity is formed, and the vacuum degree of the vacuum to form the negative pressure of the isolation space layer is different, then the silicone flexible film corresponds to the depth of the negative pressure at the position of the micro-lens mold hole. and curvature will also be different; after the set vacuum degree is reached in the isolation space layer of the compound eye mold, the injection cavity space of the compound eye mold is filled with photopolymer through a microflow injection pump, and it is demolded after curing. Take it out to get a curved bionic compound eye. 2. The bionic compound eye preparation method based on 3D printing and negative pressure mold molding according to claim 1, wherein the liquid silicone used in the step 2) is liquid polydimethylsiloxane, and is added with The curing agent is added in an amount of 10% to 15% of the mass of the polydimethylsiloxane, and the silicone flexible film prepared therefrom is a polydimethylsiloxane flexible film. 3. The bionic compound eye preparation method based on 3D printing and negative pressure moulding according to claim 2, wherein the spin coating method is adopted when preparing the polydimethylsiloxane flexible film, and the rotating speed of the control spin coater is 300 ~1000rpm, and heating and curing, the heating temperature is 60~80°C, and the heating time is 50~70min, and a polydimethylsiloxane flexible film with a thickness of 80~150 μm is prepared. 4. The bionic compound eye preparation method based on 3D printing and negative pressure moulding according to claim 3, it is characterized in that, after adopting spin coating method to obtain polydimethylsiloxane flexible film, first use absolute alcohol to soak for 20~ After 30 min, the polydimethylsiloxane flexible film was peeled off from the spin coater. 5 . The bionic compound eye preparation method based on 3D printing and negative pressure mold molding according to claim 1 , wherein the box cover in the mold box device is made of liquid silicone through mold injection. 6 . 6 . The method for preparing a bionic compound eye based on 3D printing and negative pressure mold molding according to claim 1 , wherein, in the step 4), the injection molding cavity of the compound eye mold is filled with photosensitive polymer through a microfluidic injection pump. 7 . The injection rate of the substance was 80-150 μL/min. 7 . The bionic compound eye preparation method based on 3D printing and negative pressure moulding according to claim 1 , wherein the photosensitive polymer used in the step 4) is UV-curable photosensitive adhesive NOA81. 8 . 8. The bionic compound eye preparation method based on 3D printing and negative pressure moulding according to claim 7, is characterized in that, after the injection cavity space of compound eye mould is filled with UV-curable photosensitive adhesive NOA81 by microfluidic injection pump , The specific method of curing treatment is: put the compound eye mold into the ultraviolet light equipment for ultraviolet light curing, the ultraviolet light exposure power is 200~400W, and the exposure time is 1~2min, so that the ultraviolet curing photosensitive adhesive NOA81 is cured.