Light-insensitive stretchable proximity sensor array capable of realizing full coating of three-dimensional non-developable curved surface and preparation method of light-insensitive stretchable proximity sensor array

Abstract

The invention discloses a light-insensitive stretchable proximity sensor array capable of realizing full coating on a three-dimensional non-developable curved surface and a preparation method thereof. The light-insensitive stretchable proximity sensing array comprises a double-layer elastomer substrate, a light-insensitive blended film and a patterned composite electrode which are sequentially compounded, the light-insensitive blended film is a blended film of an organic semiconductor and an elastomer; preferably, the light insensitive blended thin film is a blended thin film of DPPT-TT or IDT-BT and SEBS H1221 (Styrene-Ethylene-Butylene-Styrene). The sensor prepared on the basis of the DPPT-TT / SEBS H1221 blended film has light insensitivity, and interference of ambient light on device response signals is effectively eliminated; the method provided by the invention can be combined with an elastomer, the stretchable proximity sensor array can realize full coating of a three-dimensional non-developable curved surface, conformal fitting of human skin is realized, and development and commercial application of electronic skin are promoted.

Description

Technical Field

[0001] The invention relates to a light-insensitive stretchable proximity sensor array capable of fully covering a three-dimensional non-developable surface and a preparation method thereof, and belongs to the field of organic electronics. Background Art

[0002] In recent years, with the development and breakthrough of flexible electronics, materials science, manufacturing technology, intelligent algorithms and other technologies, electronic skin has received extensive attention and development, showing great application prospects in the fields of humanoid robots, human-computer interaction, medical health, wearable devices, etc. ( Nature , 2021, 591: 685; Nat. Mach. Intell. 2023, 5, 1344-1355; Annu. Rev. Biomed. Eng. 2024, 26(1): 331-355.). According to IDTechEx data, the global electronic skin market size in 2023 was approximately US$830 million. In the future, the electronic skin market will continue to develop, and the market size is expected to exceed US$6 billion in 2028. As a flexible sensing system, electronic skin can simulate the characteristics and sensing functions of human skin, such as contact, pressure, temperature, etc., by integrating sensors with different functions. Science 2023, 380, 735-742; Sci. Adv. 2025, 11). To further realize the conformal attachment and sensing functions of electronic skin, it is urgent to develop sensors that can be scalably prepared, have high stretchability, and are light-insensitive.

[0003] Currently, there are two main methods to achieve the attachment of sensors to three-dimensional surfaces: (1) Structural design. Precise design of rigid materials, connections, and device distribution to achieve bending or stretching of the device, thereby ensuring its adhesion to the three-dimensional surface ( Nat. Commun. 2024, 15, 9513; ACS Nano 2025, 19, 5613-5628). For example, Pan Taisong's team prepared a stretchable skin patch by designing a serpentine structure, which improved the stretchability and flexibility of the skin patch. ( Adv. Mater. 2024, 36, 2402221). However, the preparation process of structured design is relatively complex, the integration is relatively low, and the conformal bonding ability is poor, which makes it difficult to achieve widespread application of electronic skin. (2) Flexible material design. Flexible sensors are prepared using flexible materials or ultra-thin structures to achieve three-dimensional surface bonding ( Chem. Eng. J . 2024, 491, 152135; ACS Nano2023, 17, 5211-5295). For example, Yiyu Cai's team used polyimide as a substrate and prepared ultrathin (0.25-0.45 mm) fingertip sensors that can be integrated into gloves through 3D printing ( Adv. Mater. Interfaces 2022, 9(21): 2200621.). However, flexible sensors have difficulty working properly under high strain and dynamic stability, and it is difficult to achieve full coverage of complex surfaces.

[0004] Semiconductor-based sensors have outstanding advantages in output signal, manufacturing process, and mechanical properties. However, most semiconductors are photosensitive ( Nat. Commun. 2019, 10, 12; Int. J. Biol. Macromol. 2022,195, 287-293). Photosensitivity can cause devices to lose their stable electrical performance in environments with fluctuating lighting, affecting measurement results and even causing device failure. Currently, relatively little research has been conducted on imparting light-insensitive properties to semiconductors. Yongtaek Hong's team discovered that SWCNTs have different light responses to the power level of the light source, and by controlling the external lighting conditions, they achieved light-insensitive applications for the device. ACS Appl. Mater. Interfaces 2023, 15, 3192-3201). Youngkyoo Kim's team designed and synthesized an n-type polymer semiconductor with very low photosensitivity, achieving an extremely low photoresponsivity of the device ( ACS Appl. Electron. Mater. 2025, 7, 64-72). Combined with the above results, there is still a lack of simple preparation methods to achieve light-insensitivity of semiconductors.

[0005] Among various sensors, proximity sensors can detect conductors and insulators in a non-contact manner, making them ideal for simulating the touch sensing function of human skin (ACS Materials Lett. 2022, 4, 2261-2272; Adv. Mater. 2023, 35, 2304701; ACS Appl. Mater. Interfaces 2025, 17, 6604-6613). Currently, a method for preparing stretchable proximity sensors with simple steps, large-scale fabrication, high-precision patterning, compatibility with flexible elastic materials, and light insensitivity is needed to facilitate the development and commercial application of electronic skin. Summary of the Invention

[0006] The application aims to provide a light-insensitive stretchable proximity sensing array capable of full covering of three-dimensional non-developable surfaces and a preparation method.

[0007] The light-insensitive stretchable proximity sensing array capable of full covering of three-dimensional non-developable surfaces comprises a double-layer elastomer substrate, a light-insensitive blended film and a patterned composite electrode which are sequentially compounded. The light-insensitive blended film is a blended film of an organic semiconductor and an elastomer.

[0008] Preferably, the light-insensitive blended film is a blended film of DPPT-TT or IDT-BT and SEBS H1221, wherein the mass fraction of SEBS H1221 is 90-95%, preferably 95%.

[0009] The chemical name of DPPT-TT is poly(diketopyrrolopyrrol-thienothiophene). The chemical name of IDT-BT is poly(indacenodithiophene-alternate-benzothiadiazole). The chemical name of SEBS H1221 is styrene-ethylene-butylene-styrene block copolymer (block ratio 12:88).

[0010] Preferably, the double-layer elastomer substrate can be a PDMS / SEBS H1052 composite layer. The chemical name of PDMS is polydimethylsiloxane. The chemical name of SEBS H1052 is styrene-ethylene-butylene-styrene block copolymer (block ratio 20:80).

[0011] Preferably, the patterned composite electrode can be a PEDOT:PSS / SWCNT composite electrode. PEDOT:PSS refers to a cross-linked polymer formed by polyethylene glycol dimethyl acrylate and dithioerythritol. SWCNT refers to single-walled carbon nanotubes.

[0012] The light-insensitive stretchable proximity sensing array of the present application, wherein the thickness of the double-layered elastomer substrate is 200-400 µm; the thickness of the light-insensitive blended film is 45-55 nm; and the thickness of the patterned composite electrode is 25-35 nm.

[0013] The present application also provides a method for preparing the light-insensitive stretchable proximity sensing array, comprising the following steps: S1, depositing a double-layered elastomer substrate, a light-insensitive blended film and a composite electrode on a substrate modified with octadecyltrichlorosilane on the surface, respectively; S2, spin-coating photoresist on the surface of the composite electrode, and forming a patterned composite electrode by photolithography; S3, peeling off the double-layered elastomer substrate and laminating it on the surface of the light-insensitive blended film, and then peeling off together; S4, laminating the double-layered elastomer substrate / blended film obtained in step S3 on the surface of the patterned composite electrode, and peeling off the whole to obtain the light-insensitive stretchable proximity sensing array.

[0014] In the preparation method of the present application, the surface modification method of the substrate comprises the following steps: The substrate is sequentially cleaned with deionized water, acetone and isopropanol under ultrasonic wave, and dried with nitrogen; the surface of the substrate is treated with oxygen plasma; the substrate is then immersed in a mixed solution of n-heptane and octadecyltrichlorosilane and left standing; and finally, the substrate is cleaned with trichloromethane under ultrasonic wave.

[0015] In the preparation method of the present application, the preparation of the double-layered elastomer substrate comprises the following steps: A toluene solution (the concentration can be 60 mg / ml) of SEBS H1052 is spin-coated on the substrate, and solidified (the temperature can be 80℃, and the time can be 10 min); the surface is treated with oxygen plasma (the power is 100 W, and the time is 30 s); and then PDMS is spin-coated, and solidified (the temperature can be 70℃, and the time can be 30 min).

[0016] The double-layered elastomer substrate is used in the present application to ensure good adhesion of the final array to the object while achieving complete peeling of the blended film. Pure PDMS substrate cannot achieve peeling of the blended film in the present application, resulting in failure to proceed to the next step of preparation. Since pure SEBS substrate cannot achieve conformal adhesion to the object at the same thickness as PDMS, its Young's modulus is higher than that of PDMS, and its flexibility and deformation ability are relatively poor. Thinner SEBS is prone to self-adhesion during large-area peeling due to its strong adhesion and high surface energy, making it difficult to effectively separate the layers, and even causing damage to the subsequent peeling of the device. Therefore, the double substrate formed by thicker PDMS and thinner SEBS not only ensures the success rate of self-peeling, but also has adhesion, achieving good peeling of the blended film.

[0017] In the preparation method, the preparation of the light-insensitive blended film comprises the following steps: A DPPT-TT / SEBS H1221 trichloromethane solution (the concentration can be 10 mg / ml) is spin-coated on the substrate.

[0018] In the preparation method, the preparation of the composite electrode comprises the following steps: The PEDOT:PSS solution is spin-coated, and annealed at 70-100℃ for 60-90 minutes; after nitric acid treatment for 2-3 minutes, the sample is cleaned with deionized water; the aqueous dispersion of SWCNT is sprayed, and after nitric acid treatment for 2-3 minutes, the sample is cleaned with deionized water and dried with nitrogen.

[0019] In the preparation method, in step S2, the photolithography comprises the following steps: The photoresist is spin-coated and cured at 80-100℃ for 3-5 minutes; after ultraviolet exposure, the sample is developed in AZ400K developer for 1-2 minutes; and the patterned composite electrode is formed by oxygen plasma etching.

[0020] In the preparation method, the substrate can be a silicon, silicon dioxide or glass wafer.

[0021] The light-insensitive stretchable proximity sensor array provided by the application can realize full coverage of a three-dimensional non-developable surface, and the preparation method is simple in process and can be used to prepare a large-scale, high-precision and patterned proximity sensor array; the sensor prepared based on the DPPT-TT / SEBS H1221 blended film has light-insensitivity, and effectively eliminates the interference of ambient light on the response signal of the device; the method provided by the application can be combined with an elastomer, and the stretchable proximity sensor array can realize full coverage of a three-dimensional non-developable surface, realize conformal fitting of human skin, and promote the development and commercial application of electronic skin. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Fig. 1 is a structural schematic diagram of a hard light-insensitive proximity sensor according to Embodiment 1 of the application.

[0023] Figure 2 Fig. 3 is a response signal of the hard light-insensitive proximity sensor (DPPT-TT / SEBS H1221 blended film) of Embodiment 1 of the application under different proximity distances, respectively under ambient light conditions and dark state conditions.

[0024] Figure 3 Fig. 5 is a microscope photo of a stretchable light-insensitive proximity sensor according to Embodiment 2 of the application.

[0025] Figure 4 Fig. 6 is a stretchable photo of the stretchable light-insensitive proximity sensor according to Embodiment 2 of the application.

[0026] Figure 5 is the proximity response of the stretchable photo-insensitive proximity sensor of embodiment 2 of the present application at different strains (proximity distance: 1 cm).

[0027] Figure 6 is the cyclic proximity response of the stretchable photo-insensitive proximity sensor of embodiment 2 of the present application (at 40% strain) under dark and ambient light conditions, respectively.

[0028] Figure 7 is the photo of the photo-insensitive stretchable proximity sensor array electrode of embodiment 3 of the present application, which can realize full coverage of three-dimensional non-developable surfaces.

[0029] Figure 8 is the photo of the photo-insensitive stretchable proximity sensor array of embodiment 3 of the present application, which can realize full coverage of three-dimensional non-developable surfaces, and the full coverage process picture of the simulated fake hand finger.

[0030] Figure 9 is the response signal graph of the photo-insensitive stretchable proximity sensor array of embodiment 3 of the present application to hair.

[0031] Figure 10 is the response signal graph of the proximity sensor of embodiment 2 of the present application with different SEBS H1221 mass ratio blend films at different proximity distances, respectively under ambient light conditions and dark state conditions.

[0032] Figure 11 is the response signal of the hard photo-insensitive proximity sensor (IDT-BT / SEBS H1221 blend film) of embodiment 1 of the present application at different proximity distances, respectively under ambient light conditions and dark state conditions. DETAILED DESCRIPTION

[0033] The experimental methods used in the following examples are conventional methods unless otherwise specified.

[0034] The materials, reagents, etc. used in the following examples can be obtained from commercial channels unless otherwise specified.

[0035] Example 1, preparation of hard photo-insensitive proximity sensor (1) Substrate cleaning and modification, the specific steps are as follows: The silicon dioxide was sequentially immersed in deionized water, acetone, isopropanol and ultrasonicated for 10 min, and after each ultrasonication, it was blown dry with nitrogen. The cleaned silicon dioxide was subjected to oxygen plasma treatment (power: 100 W, time: 0.5 min), and then the silicon dioxide and octadecyltrichlorosilane were placed in a vacuum drying oven together, heated at 60 ℃ for 30 min, and then immersed in chloroform and ultrasonicated for 10 min. After the end of the ultrasonication, the silicon dioxide substrate modified with octadecyltrichlorosilane was obtained.

[0036] (2) Preparation of DPPT-TT / SEBS H1221 blend film on the surface-modified silica substrate with octadecyltrichlorosilane after step (1), the specific steps are as follows: DPPT-TT / SEBS H1221 blend solution (concentration: 10 mg / ml, SEBS H1221 mass ratio: 95%, solvent: chloroform) was spin-coated (rotation speed: 5000 rpm, time: 60 s) on the surface-modified silica substrate with octadecyltrichlorosilane to obtain a DPPT-TT / SEBS H1221 blend film.

[0037] (3) Preparation of interdigital electrode on the DPPT-TT / SEBS H1221 blend film after step (2), the specific steps are as follows: A 30 nm gold interdigital electrode (deposition rate: 0.1 Å / s) was vacuum evaporated on the DPPT-TT / SEBS H1221 blend film fixed with a mask plate as an interdigital electrode, with an electrode channel length of 100 µm and a width of 3500 µm, to obtain a hard light-insensitive proximity sensor The structure of the hard light-insensitive proximity sensor prepared in this example is shown in Figure 1 .

[0038] The response signal of the proximity sensor prepared in this example is shown in Figure 2 . It can be seen that the light-insensitive DPPT-TT / SEBS H1221 proximity sensor has consistent response signals under ambient light conditions and dark state conditions at different proximity distances. The proximity sensor of this example has good light-insensitive property.

[0039] IDT-BT (poly(indenodithiophene-alternating-benzothiadiazole) / SEBS H1221 blend film) was also prepared according to this example, and the light-insensitive property of the IDT-BT / SEBS H1221 blend film was proved by a hard device, as shown in Figure 11 The response signals of the light-insensitive proximity sensor based on the IDT-BT / SEBS H1221 (SEBS H1221 mass ratio of 95%) blend film prepared in this example under ambient light conditions and dark state conditions at different proximity distances can be seen, and the proximity distance decreases from 10 cm to 1 cm (step length of 1 cm), and the response signals under ambient light conditions and dark state conditions are consistent.

[0040] Example 2, preparation of stretchable light-insensitive proximity sensor (1) Substrate cleaning and modification, the specific steps are as follows The silicon was sequentially immersed in deionized water, acetone, isopropyl alcohol for ultrasonic treatment for 10 min, and then dried with nitrogen after each ultrasonic treatment. The cleaned silicon was subjected to oxygen plasma treatment (power: 100 W, time: 3 min). The silicon was placed in an octadecyltrichlorosilane solution (volume ratio of n-heptane: octadecyltrichlorosilane = 1000:1) and soaked for 5 min, then taken out and ultrasonically treated in chloroform for 10 min, and dried with nitrogen. Thus, a silicon substrate modified with octadecyltrichlorosilane on the surface was obtained.

[0041] (2) A PDMS / SEBS H1052 double-layer elastomer substrate was prepared on the substrate obtained in step (1), and the specific steps were as follows: SEBS H1052 solution (concentration: 60 mg / ml, solvent: toluene) was spin-coated (rotation speed: 1000 rpm, time: 60 s) on the silicon substrate modified with octadecyltrichlorosilane on the surface, and then dried in a drying oven at 80 ℃ for 10 min. After oxygen plasma treatment (power: 100 W, time: 30 s), PDMS (crosslinking ratio: 10:1) was spin-coated, and then dried in a drying oven at 70 ℃ for 30 min. Thus, a PDMS / SEBS H1052 double-layer elastomer substrate with a thickness of 220 µm was obtained. (3) A DPPT-TT / SEBS H1221 blend film was prepared on the substrate obtained in step (1), and the specific steps were as follows: DPPT-TT / SEBS H1221 blend solution (concentration: 10 mg / ml, SEBS H1221 mass ratio: 95%, solvent: chloroform) was spin-coated (rotation speed: 5000 rpm, time: 60 s) on the silicon substrate modified with octadecyltrichlorosilane on the surface. Thus, a DPPT-TT / SEBS H1221 blend film with a thickness of 45 nm was obtained.

[0042] (4) A composite electrode of a single device was prepared on the substrate obtained in step (1), and the specific steps were as follows: PEDOT:PSS solution (PH 1000 stock solution, volume ratio: 6% ethylene glycol, 0.2% FS-30) was spin-coated (rotation speed: 6000 rpm, time: 60 s) on the silicon substrate modified with octadecyltrichlorosilane on the surface. Then, the substrate was annealed in a drying oven at 100 ℃ for 60 min. The substrate was then placed in nitric acid for 3 min and washed with deionized water. After drying with nitrogen, SWCNT aqueous dispersion was sprayed on the substrate, which was then placed in nitric acid for 3 min and washed with deionized water, and then dried with nitrogen.

[0043] A photoresist (AZ 5200NJ) was spin-coated (rotation speed: 6000 rpm, time: 40 s) on the PEDOT:PSS / SWCNT film, and cured at 100 ℃ for 3 min on a hot plate. The photoresist film except for the single interdigital electrode pattern was irradiated with UV light of wavelength 365 nm for 10 s, and then developed in a dilute developer AZ 400K (dilution ratio: 3:1) for 1 min, fixed in deionized water for 2 s, and dried with nitrogen. The PEDOT:PSS / SWCNT film not covered by the photoresist was plasma etched (power: 100 W, time: 4 min), leaving a patterned single device composite electrode on the silicon substrate, with a thickness of 30 nm.

[0044] The silicon with the patterned electrode was placed in a vacuum drying box with octadecyltrichlorosilane, heated at 60 ℃ for 30 min, and then soaked in acetone to remove the photoresist. The composite electrode of the single device was obtained.

[0045] (5) The PDMS / SEBS H1052 double-layer elastomer substrate obtained in step (2) was peeled off from the surface of the silicon substrate, laminated on the DPPT-TT / SEBS H1221 blend film obtained in step (3), and then peeled off as a whole and laminated on the composite electrode of the single device obtained in step (4). After complete peeling, the stretchable light-insensitive proximity sensor was obtained.

[0046] The microscope photograph of the stretchable light-insensitive proximity sensor prepared in this example is shown in Figure 3 .

[0047] The stretchable light-insensitive proximity sensor prepared in this example is shown in Figure 4 . It can be seen that the device has good stretchability, proving that the device is a stretchable proximity sensor.

[0048] The proximity response (proximity distance: 1 cm) of the stretchable light-insensitive proximity sensor prepared in this example under different strains is shown in Figure 5 . It can be seen that the device can exhibit good proximity response in the range of 55% strain, proving that the device has good stretchability while ensuring its electrical performance.

[0049] The cyclic proximity response of the stretchable light-insensitive proximity sensor prepared in this example (under 40% strain) under dark and ambient light conditions, respectively, is shown in Figure 6 . It can be seen that the device can exhibit consistent proximity response under dark and ambient light conditions in the stretched state, proving that the stretchable device has good light-insensitivity.

[0050] According to the present embodiment, the present application also prepared different SEBS H1221 mass ratio blend film proximity sensor, only adjust step (3), adjust SEBS H1221 mass ratio to 0 and 50%, other steps are the same as the present embodiment. The response signal diagram of the obtained proximity sensor under ambient light conditions and dark state conditions at different proximity distances is shown in Figure 10 It can be seen that when the mass ratio of SEBS H1221 is 95%, the response signals are almost completely coincident, indicating that the blend film realizes light insensitivity at this ratio.

[0051] Example 3, preparation of light-insensitive stretchable proximity sensor array capable of full coating of three-dimensional non-developable curved surface (1) Substrate cleaning and modification, the specific steps are as follows The 4-inch silicon wafer was sequentially immersed in deionized water, acetone, isopropyl alcohol for ultrasonic treatment for 10 min, and after each ultrasonic treatment, it was blown dry with nitrogen; the cleaned silicon was subjected to oxygen plasma treatment (power: 100 W, time: 3 min), and then was placed in octadecyltrichlorosilane solution (volume ratio of n-heptane: octadecyltrichlorosilane = 1000: 1) for 5 min, then was taken out and ultrasonically treated in chloroform for 10 min, and was blown dry with nitrogen, thereby obtaining a 4-inch silicon wafer substrate modified with octadecyltrichlorosilane on the surface.

[0052] (2) PDMS / SEBS H1052 double-layer elastomer substrate was prepared on the substrate obtained in step (1), and the specific steps were as follows: SEBS H1052 solution (concentration: 60 mg / ml, solvent: toluene) was spin-coated (rotation speed: 1000 rpm, time: 60 s) on the 4-inch silicon wafer substrate modified with octadecyltrichlorosilane on the surface, and was dried in a drying oven at 80°C for 10 min, and then was spin-coated with PDMS (crosslinking ratio: 10:1) after oxygen plasma treatment (power: 100 W, time: 30 s), and was dried in a drying oven at 70°C for 30 min, thereby obtaining a PDMS / SEBS H1052 double-layer elastomer substrate with a thickness of 220 µm.

[0053] (3) DPPT-TT / SEBS H1221 blend film was prepared on the substrate obtained in step (1), and the specific steps were as follows: DPPT-TT / SEBS H1221 blend solution (concentration: 10 mg / ml, SEBS H1221 mass ratio: 95%, solvent: chloroform) was spin-coated (rotation speed: 5000 rpm, time: 60 s) on the 4-inch silicon wafer substrate modified with octadecyltrichlorosilane on the surface, thereby obtaining a DPPT-TT / SEBS H1221 blend film with a thickness of 45 nm.

[0054] (4) A patterned electrode of the proximity sensing array is prepared on the substrate obtained in step (1), and the specific steps are as follows: PEDOT:PSS solution (PH 1000 original solution, volume ratio: 6% ethylene glycol, 0.2% FS-30) is spin-coated (rotation speed: 6000 rpm, time: 60 s) on a 4-inch silicon wafer substrate modified with octadecyltrichlorosilane on the surface, and is annealed in a drying oven at 100 ℃ for 60 min. Stand in nitric acid for 3 min, and wash in deionized water. After blowing dry with nitrogen, spray the SWCNT aqueous dispersion, stand in nitric acid for 3 min, wash in deionized water, and blow dry with nitrogen.

[0055] Photoresist (AZ 5200NJ) is spin-coated (rotation speed: 6000 rpm, time: 40 s) on the PEDOT:PSS / SWCNT film, and is cured at 100 ℃ for 3 min on a baking table. The photoresist film outside the array electrode pattern is irradiated with ultraviolet light with a wavelength of 365 nm for 10 s, and then is developed in a diluted developer AZ 400K (dilution ratio: 3:1) for 1 min, fixed in deionized water for 2 s, and blown dry with nitrogen. The PEDOT:PSS / SWCNT film not covered by the photoresist is plasma etched (power: 100 W, time: 4 min), leaving a patterned array electrode on the silicon substrate.

[0056] The 4-inch silicon wafer with the patterned electrode is placed in a vacuum drying oven together with octadecyltrichlorosilane, heated at 60 ℃ for 30 min, and then soaked in acetone to remove the photoresist. The array composite electrode with a thickness of 30 nm is obtained.

[0057] (6) The PDMS / SEBS H1052 double-layer elastomer substrate obtained in step (2) is peeled off from the surface of the 4-inch silicon wafer substrate, laminated on the DPPT-TT / SEBS H1221 blended film obtained in step (3), and then laminated on the array electrode obtained in step (4) after the whole is peeled off. After complete peeling, the stretchable light-insensitive proximity sensing array is obtained.

[0058] The photograph of the array electrode prepared in this example is shown in Figure 7 It can be seen that a wafer-level array with a complex pattern is prepared, proving that the method can realize the preparation of a large-scale patterned array.

[0059] The full wrapping process of the proximity sensing array prepared in this example on a simulated artificial hand finger is shown in Figure 8 It can be seen that the array after shape design can realize all-around wrapping of a three-dimensional object without any interfacial adhesive, proving that the array can realize full wrapping of a three-dimensional non-developable surface.

[0060] The light-insensitive stretchable proximity sensing array prepared in this example can realize full coating of three-dimensional non-developable curved surfaces. The response signal of the array to hair is as shown in Figure 9 As can be seen from the array output response signal, the array can normally detect the proximity object after being coated on the three-dimensional non-developable curved surface.

Claims

1. A light-insensitive stretchable proximity sensor array capable of fully covering a three-dimensional non-developable surface, comprising a double-layered elastomer substrate, a light-insensitive blend film, and a patterned composite electrode; The light-insensitive blended film is a blended film of an organic semiconductor and an elastomer.

2. The light-insensitive stretchable proximity sensor array according to claim 1, wherein: The light-insensitive blend film is a blend film of DPPT-TT or IDT-BT and SEBS H1221, wherein the mass fraction of the SEBS H1221 is 90-95%.

3. The light-insensitive stretchable proximity sensor array according to claim 1 or 2, wherein: The double-layer elastomer substrate is a PDMS / SEBS H1052 composite layer; The patterned composite electrode is a PEDOT:PSS / SWCNT composite electrode.

4. The light-insensitive stretchable proximity sensor array according to any one of claims 1 to 3, wherein: The thickness of the double-layer elastomer substrate is 200-400 μm; the thickness of the light-insensitive blend film is 45-55 nm; and the thickness of the patterned composite electrode is 25-35 nm.

5. A method for preparing the light-insensitive stretchable proximity sensor array according to any one of claims 1 to 4, comprising the following steps: S1, depositing a double-layer elastomer substrate, a light-insensitive blend film, and a composite electrode on a substrate surface modified with octadecyltrichlorosilane; S2, spin-coating a photoresist on the surface of the composite electrode, and photolithographically forming a patterned composite electrode; S3, peeling off the double-layer elastomer substrate and laminating it on the surface of the light-insensitive blend film, and then peeling them together; S4. Laminating the double-layer elastomer substrate / blended film obtained in step S3 onto the surface of the patterned composite electrode, and peeling off the entire layer.

6. The preparation method according to claim 5, characterized in that: The surface modification method of the substrate comprises the following steps: The substrate is ultrasonically cleaned with deionized water, acetone and isopropyl alcohol in sequence and dried with nitrogen; the surface of the substrate is treated with oxygen plasma; the substrate is then immersed in a mixed solution of n-heptane and octadecyltrichlorosilane and allowed to stand; and finally, ultrasonic cleaning with chloroform is performed.

7. The preparation method according to claim 5 or 6, characterized in that: The preparation of the double-layer elastomer substrate comprises the following steps: A SEBS H1052 toluene solution was spin-coated on the substrate and solidified; the surface was treated with oxygen plasma; and then PDMS was spin-coated and solidified.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The preparation of the light-insensitive blend film comprises the following steps: A DPPT-TT / SEBS H1221 chloroform solution was spin-coated on the substrate.

9. The preparation method according to any one of claims 5 to 8, characterized in that: The preparation of the composite electrode comprises the following steps: Spin-coat the PEDOT:PSS solution, anneal at 70-100°C for 60-90 minutes, treat with nitric acid for 2-3 minutes, and then rinse with deionized water; spray-coat the SWCNT aqueous dispersion, treat with nitric acid for 2-3 minutes, and then rinse with deionized water and blow dry with nitrogen.

10. The preparation method according to any one of claims 5 to 9, characterized in that: In step S2, the photolithography includes the following steps: Spin-coat the photoresist and cure it at 80-100°C for 3-5 minutes; after UV exposure, develop it with AZ400K developer for 1-2 minutes; and etch it with oxygen plasma to form a patterned composite electrode.

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