CN115406856A - Heat radiation detection type bionic infrared sensing element and preparation method thereof - Google Patents

Abstract

The invention relates to a heat radiation detection type bionic infrared sensing element and a preparation method thereof, wherein the preparation method comprises the following steps: the device comprises a porous inner core absorption layer, an absorption layer peripheral film, a transparent quartz tube, a quartz tube wall bionic infrared sensing film and a piezoelectric film which are sequentially arranged from inside to outside; the porous core absorption layer is composed of polydimethylsiloxane, a curing agent and SiO 2-5um in diameter which are arranged on a steel wire ₂ The absorbing layer outer peripheral film and the porous core absorbing layer are made of the same material, namely 3um SiO ₂ The microspheres are dispersed in a polydimethylsiloxane substrate, and the bionic infrared sensing film on the wall of the quartz tube is an infrared sensing film with a dome-like structure and is coated on the outer wall of the transparent quartz tube; piezoelectric filmThe film is packaged at the top of the quartz tube; the invention has the advantages that: the detection sensitivity of the infrared signal is improved, the response time is prolonged, and the infrared detection sensor is suitable for performing remote detection operation under any weather environment.

Description

A thermal radiation detection bionic infrared sensing element and its preparation method

technical field

The invention relates to the technical field of infrared detection, in particular to a thermal radiation detection type bionic infrared sensing element for detecting infrared signals and a preparation method thereof.

Background technique

Due to its good universality, environmental adaptability and strong anti-interference ability, infrared detection sensors are widely used in military, medical services, industrial production, meteorology and other fields. Thermal radiation detection infrared sensing element is the most widely used infrared detection sensor. Its working principle is to prepare sensitive elements based on antimony, nickel and other metal sheets or semiconductor thin film materials. The temperature change caused by absorbing infrared radiation causes The physical properties of the material change, and then the absorbed infrared radiation is determined by measuring the change of the physical parameters to realize the long-distance detection of the object.

At present, the ability of infrared detection systems on the market to process infrared signals is limited by the signal strength. For efficient and sensitive infrared signal receiving, processing and amplification systems, the detection sensitivity is low and the response time is long. The ability to perceive weak signals is an important problem faced by infrared detection sensing elements today.

Contents of the invention

In view of the above problems, the purpose of the present invention is to provide a thermal radiation detection type bionic infrared sensing element and its preparation method, which are used to solve the problems of low detection sensitivity and long response time of the existing infrared detection type sensor signal receiving and processing.

The thermal radiation detection type bionic infrared sensing element provided by the present invention comprises: a porous core absorbing layer, a peripheral film of the absorbing layer, a transparent quartz tube, a bionic infrared sensing film and a piezoelectric film arranged on the wall of the quartz tube in sequence from the inside to the outside;

The porous core absorption layer is composed of polydimethylsiloxane, curing agent and _SiO2 microspheres with a diameter of 2-5um arranged on the steel wire, wherein polydimethylsiloxane (PDMS), solidified The mass fraction between SiO ₂ microspheres with a diameter of 2-5um is PDMS: 57.5wt%-62.5wt%, curing agent: 4.0wt%-6.25%, SiO ₂ : 31.25-38.5wt%;

The peripheral film of the absorption layer and the porous core absorption layer are selected from the same material, which is 3um SiO microspheres dispersed in polydimethylsiloxane matrix (mass ratio between ₁ :2-1:3), and the periphery of the absorption layer The outer surface of the film is a laser-etched inverted mold structure film, which is coated on the periphery of the porous core absorbing layer; the porous core absorbing layer is filled in the transparent quartz tube, forming two upper and lower chambers with the bottom of the quartz tube and the piezoelectric film, the lower chamber and the piezoelectric film. The porous core absorbing layer is filled with water, which converts the volume change caused by the temperature change into the volume change of the internal filling liquid (water);

The bionic infrared sensing film on the wall of the quartz tube is an infrared sensing film imitating a dome structure, which is coated on the outer wall of the transparent quartz tube; the piezoelectric film connected to the readout information is packaged on the top of the quartz tube;

Among them, a plurality of convex outer edge convex hulls are evenly distributed on the bionic infrared sensing film on the quartz tube wall, and the outer edge curve is the fitting curve of the sensor imitating the "dome" structure of the gilding beetle. The curve formula is as follows:

f outside (x)=a1*x^(6)+a2*x^(5)+a3*x^(4)+a4*x^(3)a5*x^(2)+a6*x+a7

where 0≤x≤10,

Where 0≤x≤10, a1=-1.421e-03a2=-2.11e-02, a3=-1.08e-01, a4=-4.14e-02, a5=6.52e-01, a6=2.24e-01 , a7=4.6715.

As a preferred structure of the present invention, the interior of the porous core absorption layer is a columnar cavity with a diameter of 100-250um.

Another object of the present invention is to provide a method for preparing a quartz tube wall bionic infrared sensitive film, the specific steps comprising: coating a photoresist on a silicon wafer substrate by a self-rotating glue leveler at a low speed of 500r/min-600r/min. Glue and keep it for 30-50s, then switch to high speed 1500r/min-1800r/min and keep it for 30-50s; the photoresist is spread into a uniform film under the action of centrifugal force, and then the silicon wafer after the glue is placed in a vacuum drying In the box, keep at 50-80°C for 15-20 minutes; after the film is placed in the UV lamp for 5min-10min to stabilize, the pre-baked silicon wafer is exposed for 50s-70s; the exposed silicon wafer is placed in a vacuum drying In the box, keep at 80°C-95°C for 15-20 minutes; place the post-baked silicon wafer in the developer for 20s-50s development; then rinse the developed silicon wafer with deionized water for 3-5 times, Remove residual stains on the surface; at room temperature, dry the sample with a hair dryer; a silicon wafer template with the "dome" sensor structure of the gilding beetle can be obtained; add 100mL water and absolute ethanol (volume ratio 1:3- 1:4) and mix thoroughly, put the imitation "dome" structure template in a beaker, clean the beaker in an ultrasonic cleaner for 10-15 minutes, and then dry it with a hair dryer; then use crystal epoxy (ring) at room temperature Oxygen resin) A/B glue is configured with the first injection reagent (mass ratio between 3:1-4:1), and the second injection reagent is configured with PDMS main agent and curing agent (mass ratio 10:1-12 :1), stir evenly and place it in a vacuum box, control the vacuum at -0.7MPa to -0.5MPa and keep it for 30-50 minutes to remove air bubbles, take out the pouring reagent; Drop the reagent on the silicon wafer template (slightly thick), let it stand for 10-15 minutes to fully immerse into the template structure and spread evenly, place it in an electric blast drying oven, set the temperature to 60°C-75°C, After curing for 2-3 hours, take out the sample, peel it off from the template, and use it as the intermediate template for the second inversion; use a glass rod to drop the second inversion reagent on the intermediate template, and let it stand for 10-20 minutes to make it It is fully immersed into the inside of the template structure and spread evenly. Place it in an electric blast drying oven, set the temperature at 80°C-90°C, and cure for 2-3 hours. Take out the sample and peel it off from the intermediate template to obtain a The imitation "dome" structure film with the same surface structure.

Another object of the present invention is to provide a kind of preparation method of porous inner core absorption layer, concrete steps comprise: first in the mixed solution of adding 100mL water and dehydrated alcohol in beaker (volume ratio between 1:3-1:4) , and then stick the sponge sheet on the top of the quartz tube mold with ordinary glue, insert several 100um-250um steel wires into it after it dries, and try to make the steel wires evenly distributed in the sponge sheet; then use 5.75g-6.25g PDMS master at room temperature agent, 0.4g-0.625g of curing agent and 3.125g-3.85g of SiO ₂ microspheres with a diameter of 2-5um to configure injection molding reagents, stir them evenly with a glass rod and place them in a vacuum box, use a vacuum pump and control the vacuum degree Take it out at -0.7MPa to -0.5MPa and keep it for 30-40 minutes to remove air bubbles; then use a scalpel blade to gently cut the adhesive layer between the sponge sheet and the quartz tube mold, add the reagent to the quartz tube mold, and then put the sponge sheet Paste it back to the top of the quartz tube mold, and finally place the mold in the vacuum box, turn on the vacuum pump, control the vacuum degree at -0.7MPa to -0.5MPa and keep it for 30min-40min to remove air bubbles, take out the mold; place it in an electric blast to dry In the box, set the temperature at 80°C-90°C, and cure for 2-3 hours; finally, a columnar cavity with a diameter of 100-250um is obtained; the anti-reflection and anti-reflection film is coated on the outer wall of the encapsulated quartz tube, and the anti-reflection absorption film is used at the same time The thin film is coated on the outer surface of the porous core absorbing layer, and finally the porous core absorbing layer is filled in the encapsulated quartz tube.

The working principle of the thermal radiation detection type bionic infrared sensing element of the present invention is as follows:

When the infrared radiation propagates to the surface of the infrared sensing element, it can efficiently pass through the interface between the atmospheric environment and the gradient refractive index of the bionic infrared sensing film on the quartz tube wall, and at the same time, the hard outer wall isolates the internal and external pressure of the bionic infrared sensing element structure Exchange, so it can fully ensure that the pressure signal inside the structure is absorbed by the soft signal output end, and penetrates the quartz tube wall to enter the inner core. The _SiO2 microspheres in the absorbing layer of the PDMS matrix can fully absorb infrared rays and cause the volume expansion of the absorbing layer to cause changes in the internal pore size and convert this change into a hydraulic signal, reducing the micron pore size in the absorbing layer to a strong capillary effect. Size range (0.2-20um), so under the above-mentioned two-layer pressurization mechanism, the piezoelectric film on the top of the liquid pressure presses the element to amplify the infrared signal and output an electrical signal to the display system.

Advantage of the present invention and positive effect are:

1. The sensing element of the present invention is based on the pit receptors existing in the cheek fossa of the chest of the gill beetle, which has the working characteristics of high sensitivity to infrared light, high stability and fast response, thereby improving the detection sensitivity of infrared signals and improving Response time, suitable for infrared detection sensors to perform long-distance detection operations in any climate environment.

2. The present invention is based on the characteristics of high sensitivity and high stability to infrared light of the "dome-shaped" receptors in the buccal fossa of the chest of the beetle. Since the expansion of the volume pump of the absorption layer and the increase of capillary suction are almost instantaneous, the The component can significantly improve the detection sensitivity of infrared signal processing and greatly reduce the response time. At the same time, the absorbing layer and the bionic infrared sensing film are hardly affected by the working environment, so the component can perform long-distance infrared detection in any climatic environment Operation.

3. The bionic infrared sensing element of the present invention has the advantages of reasonable structure, simple preparation process, and easy operation during use.

Description of drawings

Other objects and results of the present invention will become clearer and easier to understand by referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention. In the attached picture:

Fig. 1 is an axonometric view of the overall structure in the embodiment of the present invention.

Fig. 2 is a sectional view of the overall structure in the embodiment of the present invention.

Fig. 3 is an axonometric view of the bionic infrared sensitive film in the embodiment of the present invention.

Fig. 4 is a schematic diagram of average reflectance in an embodiment of the present invention.

Description of the drawings: piezoelectric film 1, porous core absorbing layer 2, absorbing layer peripheral film 3, transparent quartz tube 4, quartz tube wall bionic infrared sensitive film 5.

Detailed ways

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that these embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.

Example 1

1-3 show schematic diagrams of the overall structure according to an embodiment of the present invention.

As shown in Figures 1-3, a thermal radiation detection bionic infrared sensing element provided by an embodiment of the present invention includes: a porous core absorbing layer 1, a peripheral thin film 2 of the absorbing layer, a transparent quartz tube 3, and a quartz tube wall bionic infrared sensing element. Sensitive film 4 and piezoelectric film 5 connected to the readout system. The bionic infrared sensing film on the wall of the quartz tube is prepared from a silicon wafer template, epoxy resin glue, PDMS, and curing agent; the porous core absorption layer 1 is prepared from steel wire, PDMS, curing agent, and SiO ₂ microspheres. Porous core absorber layer 1 is composed of PDMS (polydimethylsiloxane), curing agent and _SiO2 microspheres with a diameter of 3-5um, wherein PDMS (polydimethylsiloxane), curing agent and a diameter of 3 The mass fractions among the three-5um SiO ₂ microspheres are PDMS: 57.5wt%-62.5wt%, curing agent: 4.0wt%-6.25%, and SiO ₂ : 31.25-38.5wt%.

As shown in Figure 1-3, the inside of the porous core absorbing layer is a columnar cavity with a diameter of 100-250um. The absorbing layer film and the porous core absorbing layer are made of the same material, which is 3um SiO ₂ microspheres dispersed in PDMS (Polydimethylene base siloxane) matrix (mass ratio between 1:2-1:3), the outer surface of the absorbing layer is a laser-etched inverted mold structure film, which is coated on the periphery of the porous core absorbing layer; the porous core absorbing layer is filled in a transparent In the quartz tube, the upper and lower chambers are formed with the bottom of the quartz tube and the piezoelectric film. The lower chamber and the porous core absorption layer are filled with water, which converts the volume change caused by the temperature change into the volume of the internal filling liquid (water) Changes; the quartz tube wall film is an infrared sensitive film imitating the "dome" structure, which is coated on the outer wall of the transparent quartz tube; the piezoelectric film connected to the readout system is packaged on the top of the quartz tube. Among them, a plurality of convex outer edge convex hulls are evenly distributed on the quartz tube wall film, and the outer edge curve is a fitting curve imitating the "dome" structure receptor of the gilding beetle. The curve formula is as follows:

f outside (x)=a1*x^(6)+a2*x^(5)+a3*x^(4)+a4*x^(3)a5*x^(2)+a6*x+a7

where 0≤x≤10,

Where 0≤x≤10, a1=-1.421e-03a2=-2.11e-02, a3=-1.08e-01, a4=-4.14e-02, a5=6.52e-01, a6=2.24e-01 , a7=4.6715.

Example 2

The thermal radiation detection type bionic infrared sensing element is mainly divided into the preparation of the peripheral film of the absorbing layer, the bionic infrared sensing film of the quartz tube wall and the absorbing layer of the porous inner core.

The preparation of the bionic infrared sensitive film on the quartz tube wall specifically includes the following steps:

Step 1: Place the silicon wafer in absolute ethanol for ultrasonic cleaning for 5-10 minutes, then take it out and wash it three times with deionized water.

Step 2: Coat the photoresist on the silicon wafer substrate at a low speed of 500r/min-600r/min in the self-rotating glue homogenizer and keep it for 30-50s, then switch to 1500r/min-1800r/min and keep it for 30 -50s. Form a uniform photoresist film

Step 3: Place the homogeneous silicon wafer in a vacuum drying oven and keep it at 50-80°C for 15-20 minutes.

Step 4: After the UV lamp is stabilized for 5min-10min, expose the pre-baked silicon wafer for 50s-70s.

Step 5: Place the exposed silicon wafer in a vacuum drying oven at 80°C-95°C for 15-20 minutes.

Step 6: Place the post-baked silicon wafer in a developer solution for 20s-50 development.

Step 7: Washing: Rinse the developed silicon wafer with deionized water for 3-5 times to remove residual stains on the surface.

Step 8: At room temperature, dry the sample with a hair dryer. The silicon wafer template with the "dome" sensor structure of the gilding beetle can be obtained, and the bionic infrared sensing film is prepared by the secondary template method. The specific steps are as follows:

Step 9: Add 100mL water and absolute ethanol (volume ratio between 1:3-1:4) into the beaker and mix thoroughly, place the imitation "dome" structure template in the beaker, and use an ultrasonic cleaner to clean it for 10-15 Blow dry with a hair dryer after minutes.

Step 10: Then use crystal glue (epoxy resin) A/B glue to configure the first pouring agent (mass ratio between 3:1-4:1) at room temperature, and use PDMS main agent and curing agent to configure the second Secondary pouring reagent (mass ratio between 10:1-12:1), stirred evenly with a glass rod, placed in a vacuum box, turned on the oil-free diaphragm vacuum pump, and controlled the vacuum at (-0.7MPa)-(- 0.5MPa) and keep it for 30-50 minutes to remove air bubbles, and take out the mold reagent.

Step 11: Use a glass rod to drop the first pouring reagent on the silicon wafer template, let it stand for 10-15 minutes to fully immerse and spread evenly, set the temperature of the electric blast drying oven to 60°C-75°C, and cure After 2-3 hours, take out the sample, peel it off from the formwork, and use it as an intermediate formwork for secondary inversion.

Step 12: Use a glass rod to drop the second pouring reagent on the intermediate template, let it stand for 10-20 minutes to fully immerse into the template structure and spread evenly, place it in an electric blast drying oven, and set the temperature The temperature is 80°C-90°C, cured for 2-3 hours, the sample is taken out, and peeled off from the intermediate template to obtain a film with an imitation "dome" structure that is completely consistent with the surface structure of the silicon wafer.

Example 3

Preparation of porous core absorbing layer:

Step 1: Add water and absolute ethanol (volume ratio between 1:3-1:4) into the beaker and mix thoroughly, place the quartz tube mold and packaged quartz tube in the beaker, and clean the beaker in an ultrasonic cleaner 10-15 minutes, remove the stains on the surface of the inner wall of the quartz tube, take out the quartz tube and dry it with a hair dryer;

Step 2: Glue the cut sponge sheet to the top of the quartz tube mold with ordinary glue, insert several 100um-250um steel wires into it after it dries, and try to distribute the steel wire evenly in the sponge sheet;

Step 3: Then configure the injection molding reagent (mass ratio 10:1:5-15:1:10) with PDMS main agent, curing agent and _SiO2 microspheres with a diameter of 2-5um at room temperature, and stir evenly with a glass rod Place it in a vacuum box, turn on the oil-free diaphragm vacuum pump, control the vacuum degree at (-0.7MPa)-(-0.5MPa) and keep it for 30-40 minutes to remove air bubbles, and take out the injection molding reagent;

Step 4: Gently scratch the adhesive layer between the sponge sheet and the quartz tube mold with a scalpel blade, extract the sponge sheet covered with steel wires to a certain height (to facilitate the addition of injection molding reagents), and add the injection molding reagents into the quartz tube mold with a medical syringe , and then stick the sponge sheet back to the top of the quartz tube mold.

Step 5: Place the mold in the vacuum box, turn on the oil-free diaphragm vacuum pump, control the vacuum degree at -(-0.7MPa)-(-0.5MPa) and keep it for 30min-40min to remove air bubbles, and take out the mold;

Step 6: Place the mold in an electric blast drying oven, set the temperature at 80°C-90°C, and cure for 2-3 hours;

Step 7: Take out the mold, pull out the steel wire (forced axially from the mold), gently tap the side wall of the mold with a diamond knife, and take out the formed porous core absorption layer;

Step 8: Wrap the anti-reflection and anti-reflection film on the outer wall of the packaged quartz tube, and at the same time cover the outer surface of the porous core absorbing layer with the anti-reflection absorbing film, and finally fill the porous core absorbing layer in the packaged quartz tube. The bionic infrared sensing element shown in Figure 1 is obtained.

After the bionic infrared sensing element was prepared by the above method, the reflective performance of the bionic sensing element film was tested using a visible light-infrared spectrophotometer. Beam Infrared Spectrophotometer. The experimental test band is 1-5μm, and the test step is 20nm. For ordinary films without structure and _SiO2 microspheres, the average reflectance is 8.2%; for films with structured _SiO2 microspheres, the average reflectance is 3.4%; structured _SiO2 microspheres with different sphere diameters The reflectivity of the films is all below 2.0%, and the optimal mass ratio combination of microspheres is a 3μm SiO ₂ microsphere film with a mass ratio of 2:1, and its optimum reflectivity can be reduced to 1.45%, see Figure 4 for details.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the present invention, and should cover all Within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (4)

1. A heat radiation detection type bionic infrared sensing element is characterized by comprising: the device comprises a porous inner core absorption layer, an absorption layer peripheral film, a transparent quartz tube, a quartz tube wall bionic infrared sensing film and a piezoelectric film which are sequentially arranged from inside to outside;

the porous inner core absorption layer is composed of polydimethylsiloxane, a curing agent and SiO 2-5um in diameter, which are arranged on a steel wire ₂ The microspheres are combined, wherein the polydimethylsiloxane, the curing agent and SiO with the diameter of 2-5um ₂ The mass fractions of the microspheres are 57.5wt% -62.5wt% of PDMS, 4.0wt% -6.25 wt% of curing agent, and SiO ₂ :31.25-38.5wt％；

The absorbing layer outer peripheral film and the porous core absorbing layer are made of the same material, namely 3um SiO ₂ The microspheres are dispersed in a polydimethylsiloxane matrix, and the outer surface of the absorption layer peripheral film is a laser corrosion reverse mould structure film and is coated on the periphery of the porous core absorption layer; the porous inner core absorption layer is filled in the transparent quartz tube, and forms an upper chamber and a lower chamber together with the bottom of the quartz tube and the piezoelectric film, and the lower chamber and the porous inner core absorption layer are filled with water to convert the volume change caused by temperature change into the volume change of the liquid filled in the lower chamber;

the bionic infrared sensing film on the quartz tube wall is an infrared sensing film with a dome-like structure and is coated on the outer wall of the transparent quartz tube;

wherein a plurality of convex outer edge convex hulls are uniformly distributed on the bionic infrared sensing film of the quartz tube wall, the outer edge curve is a fitting curve of a receptor imitating a Gelidine beetle dome structure, and the curve formula is as follows:

f outer (x) = a1 x ^ 6) + a2 x ^ 5) + a3 x ^ 4) + a4 x ^ 3a 5 x ^ 2) + a6 x + a7

Wherein x is more than or equal to 0 and less than or equal to 10,

wherein 0 ≦ x ≦ 10, a1= -1.421e-03a2= -2.11e-02, a3= -1.08e-01, a4= -4.14e-02, a5= -6.52e-01, a6= -2.24e-01, a7= -4.6715;

the piezoelectric film is packaged on the top of the quartz tube and used for amplifying infrared signals and outputting electric signals to a display system.

2. The biomimetic infrared sensor of claim 1, wherein the inside of the porous core absorption layer is a cylindrical cavity with a diameter of 100-250 um.

3. The bionic infrared sensing element of thermal radiation detection type according to claim 1, wherein the preparation step of the bionic infrared sensing film on the quartz tube wall comprises the following steps: coating photoresist on a silicon wafer substrate at a low rotation speed of 500r/min-600r/min for 30-50s by using a self-rotating spin coater, and switching to a high rotation speed of 1500r/min-1800r/min for 30-50s; spreading the photoresist into a uniform film under the action of centrifugal force, and then placing the silicon wafer after photoresist homogenization in a vacuum drying oven, and keeping the temperature at 50-80 ℃ for 15-20 minutes; placing the film in an ultraviolet lamp for 5-10min, and exposing the silicon wafer subjected to the pre-baking treatment for 50-70 s; placing the exposed silicon wafer in a vacuum drying oven, and keeping the temperature of 80-95 ℃ for 15-20 minutes; placing the silicon wafer after post-baking treatment in a developing solution for developing for 20-50 s; then washing the developed silicon wafer with deionized water for 3-5 times to remove surface stains; drying the sample by using a blower at normal temperature; obtaining a silicon wafer template with a dome receptor structure of the ryanodine beetle; adding 100mL of water and absolute ethyl alcohol into a beaker, fully mixing, placing the bionic structure template into the beaker, placing the beaker into an ultrasonic cleaning machine, cleaning for 10-15 minutes, and drying by using a blower; preparing a first mold-reversing reagent by using crystal glue dripping A/B glue at room temperature, preparing a second mold-reversing reagent by using a PDMS (polydimethylsiloxane) main agent and a curing agent, uniformly stirring, placing in a vacuum box, controlling the vacuum degree to be-0.7 MPa to-0.5 MPa, keeping for 30-50 minutes, removing bubbles, and taking out the mold-reversing reagent; dripping a first mold-reversing reagent on a silicon wafer template by using a glass rod, standing for 10-15 minutes to ensure that the first mold-reversing reagent is fully immersed into the template structure and is uniformly spread, placing the template structure in an electric heating air blowing drying box, setting the temperature to be 60-75 ℃, curing for 2-3 hours, taking off the template, and performing secondary mold reversing; and (3) dripping the secondary mold-reversing reagent on the intermediate template by using a glass rod, standing for 10-20 minutes to ensure that the secondary mold-reversing reagent is fully immersed in the template structure and is uniformly spread, placing the template structure in an electric heating air blast drying box, setting the temperature to be 80-90 ℃, curing for 2-3 hours, taking out a sample, and removing the sample from the intermediate template to obtain the bionic film completely consistent with the surface structure of the silicon wafer.

4. The biomimetic infrared sensor element of claim 1, wherein the porous core absorption layer is prepared by steps including: adding 100mL of mixed solution of water and absolute ethyl alcohol into a beaker, adhering the sponge sheet to the top end of a quartz tube mold by using glue, and inserting a plurality of 100-250um steel wires into the quartz tube mold after the quartz tube mold is dried, so that the steel wires are uniformly distributed in the sponge sheet as much as possible; then using 5.75g-6.25g PDMS as main agent, 0.4g-0.625g curing agent and 3.125g-3.85g SiO 2-5um in diameter at room temperature ₂ Preparing an injection molding reagent from microspheres, uniformly stirring the microspheres by using a glass rod, placing the microspheres in a vacuum box, using a vacuum pump, controlling the vacuum degree to be between-0.7 MPa and-0.5 MPa, keeping the vacuum degree for 30 to 40 minutes, removing bubbles and taking out the microspheres; slightly scratching an adhesive layer between the sponge sheet and the quartz tube mold by using a dissecting blade, adding a reagent into the quartz tube mold, then sticking the sponge sheet to the top end of the quartz tube mold, finally placing the mold in a vacuum box, opening a vacuum pump, controlling the vacuum degree to be-0.7 MPa to-0.5 MPa, keeping the vacuum degree for 30min to 40min, removing bubbles, and taking out the mold; placing the mixture in an electric heating air blast drying oven, setting the temperature to be 80-90 ℃, and curing for 2-3 hours; finally obtaining a cylindrical pore cavity with the diameter of 100-250 um; coating the outer wall of the quartz tube with antireflection film, and absorbing with antireflectionThe film is coated on the outer surface of the porous kernel absorption layer, and finally the porous kernel absorption layer is filled in the packaging quartz tube.

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