Pixelated flexible composite scintillation film and preparation method and application thereof

Abstract

The invention provides a pixelated flexible composite scintillation thin film based on a template-assisted nanoimprint technology and a preparation method and application of the pixelated flexible composite scintillation thin film. The preparation method of the pixelated flexible composite scintillation film comprises the following steps: preparing the flexible composite scintillation film; and constructing a periodic nanometer photon structure pattern on the flexible composite scintillation film by using a template-assisted nanoimprint technology to obtain the pixelated flexible composite scintillation film. According to the preparation method of the pixelated flexible composite scintillation film based on the template-assisted nanoimprint technology, the process is controllable, the preparation process flow is simplified, the production cost is reduced, the spatial resolution of the flexible composite scintillation film can be effectively improved, the imaging performance of the flexible scintillation film is greatly improved, and the application prospect is wide. Wide application prospects are realized in the fields of high-resolution X-ray imaging, radiation detection and wearable medical devices.

Description

Technical Field

[0001] This disclosure relates to the field of flexible scintillation film technology, and more specifically, to a pixelated flexible composite scintillation film based on template-assisted nanoimprinting technology, its preparation method, and its application. Background Technology

[0002] X-ray imaging technology, as a non-invasive detection method, is irreplaceable in medical diagnosis (such as tumor localization), industrial non-destructive testing (such as defect analysis of aerospace composite materials), and nuclear safety monitoring. Currently, indirect conversion detectors account for 85% of the X-ray imaging market. The core component of these detectors—the scintillator material—converts high-energy rays into fluorescent signals, which are then converted into electrical signals by a photodiode, thus achieving photoelectric conversion. The high-performance scintillators required for indirect conversion detectors must meet characteristics such as high light yield, low self-absorption, and low optical crosstalk.

[0003] In recent years, flexible X-ray scintillator screens have shown great promise in practical applications. Compared to traditional rigid scintillator screens, flexible X-ray scintillator screens possess superior plasticity and morphological adaptability, enabling them to conform to complex curved surfaces and adapt to non-uniform X-ray irradiation environments, thereby effectively mitigating the image vignetting effect caused by uneven spatial distribution of radiation dose. However, in flexible X-ray scintillator screens, when the scintillator material is unevenly dispersed or has a low content, its X-ray absorption capacity will significantly decrease, accompanied by substantial scattering losses, affecting overall detection sensitivity, spatial resolution, and imaging clarity. In particular, flexible scintillators based on highly transparent organic polymers such as polydimethylsiloxane (PDMS) suffer from low refractive index and optical waveguide effects, leading to multiple scattering and non-directional propagation of some scintillating light within the film, further reducing imaging resolution.

[0004] Studies have shown that introducing periodic nanophotonic structures on the surface of flexible scintillators can excite a variety of local optical resonance modes, which have efficient light-harvesting capabilities and tunable spectral response characteristics. This helps to enhance the light emission efficiency under X-ray excitation and can effectively control the emission directionality, thereby suppressing optical crosstalk and improving imaging clarity.

[0005] Therefore, developing flexible scintillator screens with arrayed nanostructures to optimize the scintillation performance of flexible composite scintillation films, improve energy conversion efficiency, enhance emission direction control, and improve image resolution has become an important research direction for flexible X-ray detection technology. Summary of the Invention

[0006] In view of this, this disclosure provides a pixelated flexible composite scintillation film based on template-assisted nanoimprinting technology, its preparation method and application, so as to optimize the scintillation performance of the flexible composite scintillation film, while simplifying the preparation process and reducing production costs.

[0007] According to one aspect of this disclosure, a method for preparing a pixelated flexible composite scintillation film is provided, comprising: preparing a flexible composite scintillation film; and using template-assisted nanoimprinting technology to construct a periodic nanophotonic structure pattern on the flexible composite scintillation film to obtain a pixelated flexible composite scintillation film.

[0008] According to embodiments of this disclosure, the step of preparing a flexible composite scintillation film includes: grinding a scintillator material into powder; dispersing the scintillator material powder in a polymer precursor to form a suspension medium; and preparing a flexible composite scintillation film using the suspension medium.

[0009] According to embodiments of this disclosure, in the step of grinding the scintillator material into powder, the scintillator material is a metal halide scintillator material, which is a lead-based metal halide and a non-lead metal halide scintillator material; the metal halide scintillator material includes an A-site cation, a B-site metal element, and an X-site anion.

[0010] According to embodiments of this disclosure, in the metal halide scintillator material, the B-site metal element is at least one of lead (Pb), manganese (Mn), copper (Cu), silver (Ag), zirconium (Zr), tin (Sn), or antimony (Sb), and X is at least one of chlorine (Cl), bromine (Br), iodine (I), or thiocyanate (SCN).

[0011] According to embodiments of this disclosure, in the step of dispersing scintillator material powder in a polymer precursor to form a suspension medium, the scintillator material accounts for 10% to 100% of the polymer by mass, and the dispersion is performed by at least one of ultrasonication, stirring, ball milling, or dissolution.

[0012] According to embodiments of this disclosure, in the step of dispersing scintillator material powder in a polymer precursor to form a suspension medium, the polymer comprises at least one of polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF) / thermoplastic polyurethane elastomer (TPU), polydimethylsiloxane (PDMS), polyimide (PI), polyethylene terephthalate (PEI), polyethylene naphthalate (PEN), and a biodegradable paper or cellulose substrate.

[0013] According to embodiments of this disclosure, the step of preparing a flexible composite scintillation film using a suspension medium is carried out by drop coating, blade coating, or spin coating.

[0014] According to embodiments of this disclosure, in the step of constructing a periodic nanophotonic structure pattern on a flexible composite scintillation film using template-assisted nanoimprinting technology, the template is made of silicon-based, quartz, nickel-based alloy, anodized aluminum oxide (AAO), or polyurethane acrylate (PUA) material.

[0015] According to embodiments of this disclosure, in the step of constructing a periodic nanophotonic structure pattern on a flexible composite scintillation film using template-assisted nanoimprinting technology, the template is an array template, and the array is at least one of a pillar array, a hole array, or a wire grid array.

[0016] According to embodiments of this disclosure, in the step of constructing a periodic nanophotonic structure pattern on a flexible composite scintillation film using template-assisted nanoimprinting technology, the nanoimprinting technology employs at least one of nanothermal imprinting technology, ultraviolet curing imprinting technology, or microcontact printing.

[0017] According to embodiments of this disclosure, in the step of constructing a periodic nanophotonic structure pattern on a flexible composite scintillation film using template-assisted nanoimprinting technology, the nanoimprinting technology employs an imprinting pressure of 5000~50000 Pa, an exposure time of 30-300 s, and a temperature of 20-100 ℃.

[0018] According to another aspect of this disclosure, a pixelated flexible composite scintillation film is provided, which is prepared using the aforementioned preparation method.

[0019] According to another aspect of this disclosure, an application of a pixelated flexible composite scintillation film prepared by the described preparation method is provided in the fields of high-resolution X-ray imaging, radiation detection, and wearable medical devices.

[0020] The pixelated flexible composite scintillation film based on template-assisted nanoimprinting technology, its preparation method, and its application disclosed herein have the following advantages compared with existing technologies:

[0021] (1) The pixelated flexible composite scintillation film based on template-assisted nanoimprinting technology, its preparation method, and its application provided in this disclosure, are based on template-assisted nanoimprinting technology. Using a porous array template-assisted nanoimprinting transfer process, precise patterned nanostructures can be constructed on the surface of the flexible film after demolding, resulting in a pixelated flexible composite scintillation film. This effectively controls the propagation and interaction of light, optimizing the scintillation performance of the flexible composite scintillation film (the spatial resolution of the flexible composite scintillation film reached 11.1 lp / mm). This process has advantages in repeatability and controllability, is simple to prepare, and can achieve large areas (≥25 cm²). 2This process enables the large-scale fabrication of flexible scintillator thin films. Furthermore, because the templates can be reused, this process is characterized by low production costs and suitability for industrial production.

[0022] (2) Compared with traditional rigid scintillator screens, this disclosure uses a polymer film as a substrate, which has excellent flexibility and morphological adaptability, can closely fit curved structures, adapt to non-uniform X-ray irradiation environments, and expands the application of scintillators in fields such as flexible electronics and wearable devices.

[0023] (3) Compared with traditional scintillator materials, such as alkali metal halides (e.g., cesium iodide, sodium iodide) and bismuth germanate (BGO), their preparation processes are complex and costly, and their mechanical properties are poor, making them difficult to apply to high-resolution pixelation configurations. This disclosure uses metal halides with high light yield and high energy conversion efficiency, combined with solution methods to prepare flexible thin films, which not only simplifies the process and reduces costs, but also maintains excellent scintillation performance, providing a more feasible solution for high-resolution imaging applications.

[0024] (4) The pixelated flexible composite scintillation film based on template-assisted nanoimprinting technology provided in this disclosure, its preparation method and application, by detecting the spatial resolution of the prepared flexible composite scintillation film, it was found that the spatial resolution of the prepared film can reach 11.1 lp / mm, which significantly improves the imaging performance of the scintillation film. Attached Figure Description

[0025] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0026] Figure 1 A flowchart of a method for preparing a pixelated flexible composite scintillation film according to Embodiment 1 of this disclosure is shown.

[0027] Figure 2 A process flow diagram for preparing a pixelated flexible composite scintillation film according to Embodiment 1 of this disclosure is shown.

[0028] Figure 3 A powder scanning electron microscope image of the Cs3Cu2I5 scintillator material used according to Embodiment 2 of this disclosure is shown;

[0029] Figure 4 A diagram of a flexible composite film prepared according to Embodiment 2 of this disclosure is shown;

[0030] Figure 5 A scanning electron microscope image of the AAO template used according to Embodiment 2 of this disclosure is shown;

[0031] Figure 6An atomic force microscope scan of a flexible composite scintillation thin film prepared according to Embodiment 2 of this disclosure is shown;

[0032] Figure 7 An X-ray image of a flexible composite scintillation film prepared according to Embodiment 2 of this disclosure is shown.

[0033] Figure 8 The modulation transfer function (MTF) of the flexible composite scintillation film prepared according to Embodiment 2 of this disclosure is shown. Detailed Implementation

[0034] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0035] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0036] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0037] To improve the spatial resolution of flexible composite scintillation films while simplifying the fabrication process and reducing production costs, such as... Figure 1 and Figure 2 As shown, Embodiment 1 of this disclosure provides a method and process for preparing a pixelated flexible composite scintillation film. The method includes the following steps:

[0038] S1: Preparation of flexible composite scintillation thin films, specifically including:

[0039] S11: Grind the scintillator material into powder;

[0040] In this step, the scintillator material is a metal halide scintillator material, which is a lead-based metal halide and a non-lead metal halide scintillator material. This metal halide scintillator material includes an A-site cation, a B-site metal element, and an X-site anion. In the metal halide scintillator material, the B-site metal element is at least one of lead (Pb), manganese (Mn), copper (Cu), silver (Ag), zirconium (Zr), tin (Sn), or antimony (Sb), and X is at least one of chlorine (Cl), bromine (Br), iodine (I), or thiocyanate (SCN).

[0041] S12: Disperse scintillator material powder in polymer precursor to form a suspension medium;

[0042] In this step, the scintillator material accounts for 10% to 100% of the polymer by mass, and the dispersion is performed using at least one of ultrasonication, stirring, ball milling, or dissolution. The polymer comprises at least one of polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF) / thermoplastic polyurethane elastomer (TPU), polydimethylsiloxane (PDMS), polyimide (PI), polyethylene terephthalate (PEI), polyethylene naphthalate (PEN), and biodegradable paper or cellulose substrate.

[0043] S13: Prepare flexible composite scintillation films using suspension media.

[0044] In this step, flexible composite scintillation films are prepared by drop coating, blade coating, or spin coating of the suspended medium.

[0045] In step S1, compared to traditional scintillator materials such as alkali metal halides (e.g., cesium iodide, sodium iodide) and bismuth germanate (BGO), their preparation processes are complex and costly, and their mechanical properties are poor, making them difficult to apply to high-resolution pixelation configurations. This disclosure utilizes metal halides with high light yield and high energy conversion efficiency, combined with a solution method to prepare flexible composite scintillator films. This not only simplifies the process and reduces costs but also maintains excellent scintillator performance, providing a more feasible solution for high-resolution imaging applications.

[0046] S2: Using template-assisted nanoimprinting technology, periodic nanophotonic structure patterns are constructed on flexible composite scintillation films to obtain pixelated flexible composite scintillation films.

[0047] In this step, the template is made of silicon-based, quartz, nickel-based alloy, anodized aluminum oxide (AAO), or polyurethane acrylate (PUA) material.

[0048] The template is an array template, and the array is at least one of a column array, a hole array, or a wire grid array.

[0049] The nanoimprinting technology employs at least one of nanothermal imprinting, ultraviolet curing imprinting, or microcontact printing.

[0050] The nanoimprinting technology uses an imprinting pressure of 5000~50000 Pa, an exposure time of 30-300 s, and a temperature of 20-100 ℃.

[0051] Compared to traditional rigid scintillator screens, in step S2, this disclosure uses a polymer film as a substrate, which has excellent flexibility and morphological adaptability, can closely fit curved structures, and is suitable for non-uniform X-ray irradiation environments, thus expanding the application of scintillators in fields such as flexible electronics and wearable devices.

[0052] Furthermore, by employing a porous array template-assisted nanoimprint transfer process, precise patterned nanostructures can be constructed on the surface of the flexible film after demolding, resulting in a pixelated flexible composite scintillation film. This allows for effective control of light propagation and interaction, optimizing the optical performance of the flexible composite scintillation film (the spatial resolution of the flexible composite scintillation film reached 11.1 lp / mm). This process offers advantages in repeatability and controllability, is simple to fabricate, and can achieve large-area fabrication (≥25 cm²). 2 This process enables the large-scale fabrication of flexible scintillator thin films. Furthermore, because the templates can be reused, this process is characterized by low production costs and suitability for industrial production.

[0053] Based on the above Figure 1 and Figure 2 The preparation method and process of the pixelated flexible composite scintillation film shown in Example 1 are described in detail below with reference to Example 2.

[0054] In this embodiment 2, a weakly self-absorbing lead-based scintillator Cs3Cu2I5 material (photoluminescence quantum yield (PLQY) 59.9%, light yield 32000 photon / MeV) (such as...) Figure 3 The powder (as shown) was ground into powder and dispersed in a polydimethylsiloxane (PDMS) polymer precursor at a mass ratio of 15% to form a suspension medium; a flexible composite film with a thickness of 50-100 μm was prepared on a silicon substrate by spin coating (spin coating speed 500 rpm, spin coating speed 2 min). Figure 4 As shown, the area is 25 cm². 2 ); using anodized aluminum oxide (AAO) with a porous array structure as a template (e.g. Figure 5Nano-thermal embossing was performed on the image (as shown). The embossing parameters were: temperature 80 ℃, embossing pressure 20000 Pa, and embossing time 180 s. After embossing, automatic demolding was performed to obtain a pixelated flexible composite scintillation film (as shown). Figure 6 (As shown). The performance of the pixelated flexible composite scintillation film was measured using X-ray imaging equipment, and the imaging results are as follows. Figure 7 As shown (excitation voltage 50 keV, current 200 μA). Testing revealed that the pixelated flexible composite scintillation film prepared in this disclosure achieves a spatial resolution of 11.1 lp / mm at a modulation transfer function (MTF) value of 20%. Figure 8 Therefore, compared to traditional scintillator materials, such as alkali metal halides (e.g., cesium iodide, sodium iodide) and bismuth germanate (BGO), their preparation processes are complex and costly, and their mechanical properties are poor, making them difficult to apply to high-resolution pixelation configurations. The pixelated flexible composite scintillator film and its preparation method based on template-assisted nanoimprinting technology provided in this disclosure employ a simple metal halide process, which is easy to use to prepare flexible films and offers advantages such as high energy conversion efficiency, tunable wavelength, and low cost. Furthermore, the pixelated flexible composite scintillator film and its preparation method provided in this disclosure, compared to traditional rigid scintillator screens, have excellent plasticity and morphology adaptability, can conform to complex curved surface structures, and are suitable for applications in non-uniform X-ray irradiation environments.

[0055] Furthermore, based on the above-described method for preparing pixelated flexible composite scintillation films, this disclosure also provides a pixelated flexible composite scintillation film prepared by the method. Compared with traditional rigid scintillator screens, this pixelated flexible composite scintillation film has excellent plasticity and morphological adaptability, can conform to complex curved surface structures, and is suitable for applications in non-uniform X-ray irradiation environments.

[0056] Furthermore, based on the above-described method for preparing pixelated flexible composite scintillation films, this disclosure also provides an application of the pixelated flexible composite scintillation film prepared by the method in high-resolution X-ray imaging, radiation detection, and wearable medical devices, which can be widely used in high-resolution X-ray imaging, radiation detection, and wearable medical devices.

[0057] Therefore, the method for preparing pixelated flexible composite scintillation films provided in this disclosure, by employing a porous array template-assisted nanoimprinting transfer process, allows for the construction of precisely patterned nanostructures on the surface of the flexible film after demolding, resulting in pixelated flexible composite scintillation films. This enables effective control of light propagation and interaction, optimizing the optical performance of the flexible composite scintillation film (the spatial resolution of the flexible composite scintillation film reaches 11.1 lp / mm as tested). This process offers advantages in repeatability and controllability, is simple to prepare, and can achieve large-area (≥25 cm²) preparation. 2 This process enables the large-scale fabrication of flexible scintillator thin films. Furthermore, due to the reusability of the template, this process features low production costs and suitability for industrial production. It can effectively improve the spatial resolution of flexible composite scintillator thin films and significantly enhance their imaging performance, showing broad application prospects in high-resolution X-ray imaging, radiation detection, and wearable medical devices.

[0058] Those skilled in the art will understand that the features described in the various embodiments of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0059] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for preparing a pixelated flexible composite scintillation film, characterized in that, include: Preparation of flexible composite scintillation films; Using template-assisted nanoimprinting technology, periodic nanophotonic structure patterns are constructed on flexible composite scintillation films to obtain pixelated flexible composite scintillation films.

2. The method for preparing a pixelated flexible composite scintillation film according to claim 1, characterized in that, The steps for preparing the flexible composite scintillation film include: The scintillator material is ground into powder; The scintillator material powder is dispersed in the polymer precursor to form a suspension medium; Flexible composite scintillation films were prepared using a suspension medium.

3. The method for preparing a pixelated flexible composite scintillation film according to claim 2, characterized in that, In the step of grinding the scintillator material into powder, the scintillator material is a metal halide scintillator material, which is a lead-based metal halide and a non-lead metal halide scintillator material; the metal halide scintillator material includes an A-site cation, a B-site metal element, and an X-site anion.

4. The method for preparing the pixelated flexible composite scintillation film according to claim 3, characterized in that, In the metal halide scintillator material, the B-site metal element is at least one of lead (Pb), manganese (Mn), copper (Cu), silver (Ag), zirconium (Zr), tin (Sn) or antimony (Sb), and X is at least one of chlorine (Cl), bromine (Br), iodine (I) or thiocyanate (SCN).

5. The method for preparing a pixelated flexible composite scintillation film according to claim 2, characterized in that, In the step of dispersing the scintillator material powder in the polymer precursor to form a suspension medium, the mass percentage of the scintillator material to the polymer is 10% to 100%, and the dispersion is performed by at least one of ultrasonication, stirring, ball milling, or dissolution.

6. The method for preparing a pixelated flexible composite scintillation film according to claim 2, characterized in that, In the step of dispersing the scintillator material powder in a polymer precursor to form a suspension medium, the polymer comprises at least one of polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF) / thermoplastic polyurethane elastomer (TPU), polydimethylsiloxane (PDMS), polyimide (PI), polyethylene terephthalate (PEI), polyethylene naphthalate (PEN), and a biodegradable paper or cellulose substrate.

7. The method for preparing a pixelated flexible composite scintillation film according to claim 2, characterized in that, In the step of preparing a flexible composite scintillation film using a suspension medium, the preparation is carried out by drop coating, blade coating or spin coating methods.

8. The method for preparing a pixelated flexible composite scintillation film according to claim 1, characterized in that, In the step of constructing periodic nanophotonic structure patterns on flexible composite scintillation films using template-assisted nanoimprinting technology, the template is made of silicon-based, quartz, nickel-based alloy, anodized aluminum oxide (AAO), or polyurethane acrylate (PUA) material.

9. The method for preparing a pixelated flexible composite scintillation film according to claim 8, characterized in that, In the step of constructing a periodic nanophotonic structure pattern on a flexible composite scintillation film using template-assisted nanoimprinting technology, the template is an array template, and the array is at least one of a column array, a hole array, or a wire grid array.

10. The method for preparing a pixelated flexible composite scintillation film according to claim 1, characterized in that, In the step of constructing a periodic nanophotonic structure pattern on a flexible composite scintillation film using template-assisted nanoimprinting technology, the nanoimprinting technology employs at least one of nanothermal imprinting technology, ultraviolet curing imprinting technology, or microcontact printing.

11. The method for preparing a pixelated flexible composite scintillation film according to claim 1, characterized in that, In the step of constructing a periodic nanophotonic structure pattern on a flexible composite scintillation film using template-assisted nanoimprinting technology, the nanoimprinting technology employs an imprinting pressure of 5000~50000 Pa, an exposure time of 30-300 seconds, and a temperature of 20-100 ℃.

12. A pixelated flexible composite scintillation film, characterized in that, It is prepared by any one of the preparation methods according to claims 1-11.

13. The application of the pixelated flexible composite scintillation film prepared by the preparation method according to any one of claims 1-11 in the fields of high-resolution X-ray imaging, radiation detection and wearable medical devices.

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