Graphene strain structure and preparation method and application thereof

Abstract

The application discloses a graphene strain structure and a preparation method and application thereof. The structure comprises a structure substrate layer, a step cavity array, a graphene absorption layer, a flexible strain layer, a dielectric layer and a lower electrode layer. The step cavity array comprises a plurality of step cavities arranged on the structure substrate layer. Each step cavity comprises an outer cavity and an inner cavity from an opening inwards. A step surface is formed between the outer cavity and the inner cavity, and the lateral size of the outer cavity is larger than that of the inner cavity. The graphene absorption layer is arranged on the step surface of each step cavity. The flexible strain layer is attached to the outside of the step cavity array and seals the opening of each step cavity. A film side electrode layer is deposited on the side of the flexible strain layer away from the step cavity. The dielectric layer separates and fixes the flexible strain layer and the lower electrode layer, so that the film side electrode layer and the lower electrode layer form a capacitor. The application also discloses a preparation method of the graphene strain structure. The application is suitable for wide spectrum electromagnetic energy detection and conversion, and is easy to be integrated in a large area and manufactured in a large scale.

Description

Technical Field

[0001] This invention relates to the field of strain structure energy detection, specifically to graphene strain structures, their preparation methods, and applications. Background Technology

[0002] With the development of femtosecond laser processing technology, breakthroughs have been achieved in the fabrication of complex microstructures. By matching novel carbon nanomaterials with functional cavity structures, graphene strain structures can be constructed that achieve both broad-spectrum absorption and energy conversion into strain layer deformation. Graphene is an allotrope of carbon, with carbon atoms arranged in sp... 2 Hybrid bonding forms a single-layer hexagonal honeycomb lattice structure. Pure, defect-free single-layer graphene has a thermal conductivity of up to 5300 W / mK, far exceeding that of single-walled and multi-walled carbon nanotubes, exhibiting excellent thermal conductivity. Combining carbon nanomaterials with strain-structured energy detection technology, through rational structural design, enables efficient control and capture of broadband electromagnetic energy, demonstrating advantages in electromagnetic devices, radar systems, infrared detection, and biomedicine. Currently, this direction is driving the development of broadband sensing towards integration, intelligence, and multifunctionality, showing significant potential in infrared imaging, quantum sensing, and on-orbit processing, and is expected to further expand into consumer electronics and deep space exploration with advancements in fabrication processes and computational design.

[0003] At the same time, while existing strain structure energy detectors have the advantages of room temperature operation and wide spectrum adaptability, they still have shortcomings in absorption and coupling efficiency, cavity sealing and long-term reliability, effective deformation and signal-to-noise ratio after miniaturization, readout stability, array consistency, and manufacturing yield and cost control. They are difficult to achieve a comprehensive performance that balances performance and engineering under the application requirements of wide spectrum, low power consumption and large-scale integration.

[0004] Therefore, it is necessary to propose a strain structure that is compact, easy to manufacture on a large scale, and capable of achieving efficient energy capture and stable readout over a wide frequency band. Summary of the Invention

[0005] This invention provides a graphene strain structure, its preparation method, and its application, solving the problems of large structural volume, narrow response spectrum, and complex manufacturing process of strain structure energy detectors in the prior art.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a graphene strained structure, comprising: Structural base layer; A stepped chamber array includes several stepped chambers disposed on a structural base layer. Each stepped chamber includes an outer cavity and an inner cavity in sequence from the opening inward. The outer cavity and the inner cavity form a stepped surface, and the lateral dimension of the outer cavity is larger than that of the inner cavity. A graphene absorption layer is disposed on the step surface of each of the stepped chambers, and the size of the graphene absorption layer matches the opening of the stepped chamber. A flexible strain layer is attached to the outside of the stepped chamber array and seals the opening of each stepped chamber; a film-side electrode layer is deposited on the side of the flexible strain layer facing away from the stepped chamber. A dielectric layer, wherein the dielectric layer is disposed on the outer side of the film-side electrode layer; A lower electrode layer is disposed outside the dielectric layer. The dielectric layer separates and fixes the flexible strain layer from the lower electrode layer, so that the film-side electrode layer and the lower electrode layer constitute a capacitor.

[0007] Furthermore, the structural substrate layer includes a quartz plate, a germanium glass plate, a sapphire glass plate, or a silicon-based plate; the dielectric layer is PE / alumina; and the lower electrode layer is ITO glass.

[0008] Furthermore, the stepped chamber includes a circular stepped chamber, a rectangular stepped chamber, a triangular stepped chamber, or a pentagonal stepped chamber.

[0009] Furthermore, the film-side electrode layer includes a chromium / aluminum thin film, a chromium / copper thin film, a chromium / silver thin film, or a chromium / gold thin film.

[0010] Furthermore, the thickness of the graphene absorption layer is not less than 5 μm.

[0011] Furthermore, the depth of the stepped chamber is not less than 400 μm.

[0012] Furthermore, the flexible strain layer is PDMS with a thickness of no more than 40 μm.

[0013] Furthermore, the graphene absorption layer has a multilayer stacked structure, consisting of several graphene films stacked one on top of another.

[0014] Secondly, the present invention provides a method for preparing a graphene strained structure, comprising: A quartz plate is placed in a femtosecond laser processing device for initial etching, resulting in a blind hole array. The quartz plate with the blind hole array is etched a second time to obtain a stepped chamber array with internal steps; Graphene films were obtained by filtration of graphene aqueous slurry. A graphene film is attached to the surface of a quartz plate on one side of the stepped chamber array, and the graphene film is laser-etched along each stepped chamber to obtain a graphene absorption layer that matches the opening size of the stepped chamber. Remove excess graphene film; use a pin to assemble the graphene absorption layer onto the step surface of each step chamber to obtain a semi-finished component; A chromium / aluminum thin film was deposited on one side of the flexible strain layer by magnetron sputtering to form a film-side electrode layer; The side of the flexible strain layer electrode layer is attached tightly to the K9 flat glass, and then the other side of the flexible strain layer is subjected to plasma treatment in a plasma cleaning machine. K9 flat glass with a flexible strain layer attached is placed on the semi-finished component, and the side of the flexible strain layer that has been plasma treated is attached to the side of the stepped chamber array of the semi-finished component. Then, it is placed on a heating platform for hot pressing bonding, so that the flexible strain layer seals the opening of each stepped chamber. After cooling, the K9 flat glass is peeled off from the flexible strain layer. A dielectric layer is deposited on the outside of the membrane-side electrode layer, and then a lower electrode layer is deposited on the outside of the dielectric layer. The dielectric layer separates and fixes the flexible strain layer and the lower electrode layer to form a capacitor, thus completing the preparation of the graphene strain structure.

[0015] Thirdly, the present invention provides the application of the above-mentioned graphene strain structure in broadband electromagnetic energy detection.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The graphene strain structure of this invention mainly includes a stepped cavity array and a graphene absorption layer. The graphene absorption layer is attached to the step surface and its planar outline matches the opening, which can achieve stable positioning and support at the step. The graphene absorption layer can be multi-layered and its thickness is adjustable. It has high absorption performance and can absorb electromagnetic waves multiple times, effectively improving the electromagnetic wave absorption capability of traditional structures. At the same time, the graphene strain structure of this invention adopts an array arrangement, which is convenient for covering a large area and is suitable for the acquisition and conversion of a wide range of electromagnetic waves, and can adapt to complex waveband environments.

[0017] The method for preparing the graphene strain structure in this invention involves two-step etching on a quartz plate using femtosecond laser micromachining to form stepped chambers; laser patterning of the graphene film according to the opening contour of each stepped chamber; and precise attachment of the graphene absorption layer to each stepped surface using a pin, thus organically combining the stepped chamber array and the graphene absorption layer, thereby obtaining an arrayed graphene strain structure with a simple and well-aligned process.

[0018] The graphene strain structure of this invention has broad application prospects in the field of broadband energy detection, such as electromagnetic equipment, radar systems, infrared detection, and biomedicine, and can meet the needs of integrated strain structures.

[0019] Of course, implementing the various technical solutions of this invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a flowchart of the graphene strain structure and preparation method in Example 1 of the present invention; Figure 2 This is a schematic diagram of the strained graphene structure prepared in Example 1 of the present invention; Figure 3 This is a physical image of the graphene strain structure prepared in Example 1 of this invention. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0023] Example 1: The graphene strain structure parameters provided in this embodiment are as follows: The stepped chamber is a circular structure with an outer cavity diameter (opening diameter) of 3 mm and an inner cavity diameter of 2 mm. There is one graphene absorption layer, a flexible strain layer of PDMS, a chromium / aluminum metal deposited on the flexible strain layer (as a film-side electrode layer), a PE / alumina dielectric layer, and an ITO glass lower electrode layer.

[0024] The preparation method of this strained structure will be described in detail below using this as an example. See [link to relevant documentation]. Figure 1 A method for preparing a graphene strained structure, the specific steps of which are as follows: Step S1: Place a quartz plate with a surface roughness of 50nm and a thickness of 1mm (as a structural substrate layer) in a femtosecond laser processing device, and etch an array of blind holes on the upper surface of the structural substrate layer. Each blind hole has a diameter of 2mm and a depth of 0.8mm and is circular. Step S2: Perform a second etching on the blind hole array to obtain a ring array with an outer cavity diameter of 3 mm and a depth of 0.4 mm. The center of the ring array is consistent with the center of the blind hole array etched in the first step, resulting in a stepped chamber array with an outer cavity / inner cavity and a stepped surface formed therebetween. Step S3: The graphene aqueous slurry is prepared into a graphene film with a thickness of 10µm by five filtration processes and then baked at 100℃ for 30min. Step S4: Attach the graphene film tightly to the quartz plate surface on one side of the stepped chamber array, and use a femtosecond laser to etch the graphene film. The etched pattern is a 3mm diameter graphene disc covering the opening of the stepped chamber. Remove the excess graphene film outside the graphene disc array, and use a pin to position all the graphene discs on the stepped surface (0.4mm depth of the stepped chamber) to form a graphene absorption layer. Step S5: Using magnetron sputtering technology, a chromium / aluminum thin film with a thickness of 100nm / 700nm is deposited on a flexible strain layer (square PDMS) with a thickness of 25µm to form a film-side electrode layer; the side containing the film-side electrode layer is attached tightly to a K9 flat glass with a surface roughness of 50nm and a thickness of 2mm, and the other side of the flexible strain layer is subjected to Ar plasma treatment for 15min. Step S6: Tightly attach the quartz plate with the graphene absorption layer assembled in the stepped chamber array to the side of the flexible strain layer that has been plasma treated, aligning the centers of the two; place it on a heating platform and keep it at 80°C for 40 minutes for hot pressing bonding; after cooling to room temperature, remove the K9 plate glass to complete the sealing of the stepped chamber array. Step S7: A circular PE / alumina ring (as a dielectric layer) with an inner diameter of 3 mm, an outer diameter of 4 mm, and a thickness of 20 µm is deposited on the outside of the film-side electrode layer. Then, a square ITO glass with a side length of 4 mm and a thickness of 0.5 mm (as a lower electrode layer) is deposited on the outside of the dielectric layer, with the ITO surface of the lower electrode layer facing the dielectric layer and kept aligned with the center. The flexible strain layer, dielectric layer, and lower electrode layer are fixed with UV adhesive using a dispensing machine, thus completing the preparation of the graphene strain structure.

[0025] Please see Figure 2 , Figure 2 This is a schematic diagram of the graphene strained structure prepared by the method of this embodiment. As can be seen from the figure, the graphene strained structure includes: a structural substrate layer and a stepped cavity array thereon, a graphene absorber layer, a flexible strain layer, a dielectric layer, and a lower electrode layer.

[0026] Please see Figure 3 , Figure 3 The figure shows a physical image of the graphene strained structure prepared by the method of this embodiment. As can be seen from the figure, the stepped chamber array is an 8×8 rectangular array, the outer diameter of each stepped chamber is 3mm, and the film-side electrode layer / flexible strain layer is chromium / aluminum / PDMS. In other embodiments, the stepped chamber array can also be designed as other rectangular arrays or circular arrays of M×N (M and N are positive integers) according to application requirements.

[0027] This embodiment uses a single-layer graphene absorber layer as an example. It should be noted that the invention is not limited to this; the graphene absorber layer can also be a multilayer stacked structure with 2, 3, 4, 5, or N layers (N≥2). Any of the above-mentioned modified graphene strained structures obtained using the preparation method of this invention are within the scope of protection of this invention.

[0028] Example 2: The difference between this embodiment and Embodiment 1 is that the stepped chamber is rectangular, the graphene absorption layer is a three-layer stacked structure, and the film-side electrode layer is a chromium / copper thin film.

[0029] A method for preparing a graphene strained structure, the specific steps of which are as follows: Step S1: Place a quartz plate with a surface roughness of 50nm and a thickness of 1mm (as a structural substrate) in a femtosecond laser processing device, and etch a 10×12 rectangular blind hole array on the upper surface of the structural substrate. Each blind hole has a side length of 2mm and a depth of 0.8mm.

[0030] Step S2: Perform a second etching on the blind hole array to obtain a 10×12 rectangular array with an outer cavity side length of 3mm and a depth of 0.4mm; the center of the rectangular array is consistent with the center of the first etched rectangular blind hole array, forming a stepped chamber array with an outer cavity / inner cavity and a stepped surface formed therebetween.

[0031] Step S3: The graphene aqueous slurry is filtered five times to prepare a graphene film with a thickness of 8µm, and then baked at 100℃ for 30min; a total of three graphene films are prepared for use.

[0032] Step S4: The three graphene films mentioned above are sequentially attached to the quartz plate surface on one side of the stepped cavity array, and then femtosecond laser etching is performed to pattern the graphene rectangular sheet array with a side length of 3mm according to the opening contour of each stepped cavity. After removing the excess film outside the pattern, the three graphene rectangular sheets are simultaneously aligned and pushed into the center of the step surface of each stepped cavity using a pusher to form a three-layer graphene absorption layer.

[0033] Step S5: Deposit a chromium / copper thin film with a thickness of 100nm / 700nm on one side of the flexible strain layer (PDMS, thickness 25µm) by magnetron sputtering to form a film-side electrode layer; attach the side containing the film-side electrode layer to a K9 flat glass plate with a surface roughness of 50nm and a thickness of 2mm, and perform Ar plasma treatment on the other side of the flexible strain layer for 15min.

[0034] Step S6: The stepped chamber array with the three-layer graphene absorption layer is tightly attached to the plasma-treated side of the flexible strain layer, with the centers of the two aligned; it is placed on a heating platform and held at 80°C for 40 minutes for hot-press bonding; after cooling to room temperature, the K9 flat glass is removed to complete the sealing of the stepped chamber array.

[0035] Step S7: A rectangular ring of PE / alumina (as a dielectric layer) with an inner side length of 3 mm, an outer side length of 4 mm, and a thickness of 20 µm is deposited on the outside of the film-side electrode layer. Then, a square ITO glass with a side length of 4 mm and a thickness of 0.5 mm (as a lower electrode layer) is deposited on the outside of the dielectric layer, with the ITO surface of the lower electrode layer facing the dielectric layer and kept aligned with the center. The flexible strain layer, dielectric layer, and lower electrode layer are fixed with UV adhesive using a dispensing machine to complete the preparation of the graphene strain structure.

[0036] Example 3: The difference between this embodiment and Embodiment 1 is that the stepped chamber is an equilateral triangle, the stepped chamber array is a ring array, and the membrane-side electrode layer is a chromium / silver thin film; the remaining materials and parameters are the same or the parts not described are consistent with Embodiment 1 (the graphene absorption layer is a single layer, and the flexible strain layer is PDMS).

[0037] A method for preparing a graphene strained structure, the specific steps of which are as follows: Step S1: Place a quartz plate with a surface roughness of 50nm and a thickness of 1mm (as a structural substrate) in a femtosecond laser processing device, and etch a triangular ring array of blind holes on the upper surface of the structural substrate. Each blind hole has a side length of 2mm and a depth of 0.8mm.

[0038] Step S2: Perform a second etching on the blind hole array to obtain a triangular ring array with an outer cavity side length of 3mm and a depth of 0.4mm. The center of the triangular ring array is consistent with the center of the first etched triangular blind hole array, forming a ring stepped cavity array with an outer cavity / inner cavity and a stepped surface formed therebetween.

[0039] Step S3: The graphene aqueous slurry is filtered five times to prepare a graphene film with a thickness of 10µm, and then baked at 100℃ for 30min.

[0040] Step S4: Attach the graphene film tightly to the quartz plate surface on one side of the stepped chamber array, and use a femtosecond laser to etch the graphene film. The etched pattern is an equilateral triangular graphene sheet with a side length of 3mm covering the opening of the stepped chamber. Remove the excess graphene film outside the triangular sheet array, and use a pin to position all the graphene triangular sheets at the center of the stepped surface (0.4mm depth of the stepped chamber) to form a graphene absorption layer.

[0041] Step S5: Deposit a 100nm / 700nm chromium / silver thin film on one side of the flexible strain layer (PDMS, 25µm thickness) by magnetron sputtering to form a film-side electrode layer; attach the side containing the film-side electrode layer to a K9 flat glass plate with a surface roughness of 50nm and a thickness of 2mm, and perform Ar plasma treatment on the other side of the flexible strain layer for 15min.

[0042] Step S6: The stepped chamber array with the graphene absorption layer is tightly attached to one side of the flexible strain layer that has been plasma-treated, with the centers of the two aligned; it is placed on a heating platform and held at 80°C for 40 minutes for thermo-press bonding; after cooling to room temperature, the K9 flat glass is removed to complete the sealing of the stepped chamber array.

[0043] Step S7: A triangular ring PE / alumina dielectric layer with an inner side length of 3mm, an outer side length of 4mm, and a thickness of 20µm is deposited on the outside of the film-side electrode layer. Then, a square ITO glass lower electrode layer with a side length of 4mm and a thickness of 0.5mm is deposited on the outside of the dielectric layer, with the ITO surface facing the dielectric layer and the center aligned. The flexible strain layer / dielectric layer / lower electrode layer is fixed with UV adhesive using a dispensing machine to complete the preparation of the graphene strain structure.

[0044] The above embodiments are based on two-step femtosecond laser etching to form a stepped chamber array (circular, rectangular, equilateral triangular, array form can be M×N or ring) on ​​the structural substrate. The graphene film is patterned according to the opening contour and positioned on the step surface to form a graphene absorption layer (single layer or three layers, or multiple layers stacked). Subsequently, the flexible strain layer (PDMS) is sequentially assembled and fixed with its film-side electrode layer (chromium / aluminum, chromium / copper, chromium / silver), dielectric layer (PE / alumina), and lower electrode layer (ITO glass) to obtain an arrayed graphene strain structure. The geometric dimensions, array pattern, and electrode / dielectric materials can be replaced and expanded within the above process.

[0045] The graphene strain structure of this invention can be widely used in broadband electromagnetic energy detection and conversion, and can be integrated as an array pixel into electromagnetic devices, radar systems, infrared imaging and biomedical detection devices.

[0046] The graphene strain structure of this invention improves the coupling and capture efficiency of broadband energy, and has broad application prospects in broadband electromagnetic and infrared detection fields; the step surface positioning and sealing improve device stability and array consistency and reduce assembly errors; the process is scalable and supports large-area arrays and large-scale manufacturing; multilayer graphene and various chamber shapes / material configurations improve adaptability and integration.

[0047] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A method for preparing a graphene strained structure, characterized in that, include: A quartz plate is placed in a femtosecond laser processing device for initial etching, resulting in a blind hole array. The quartz plate with the blind hole array is etched a second time to obtain a stepped chamber array with internal steps; Graphene films were obtained by filtration of graphene aqueous slurry. A graphene film is attached to the surface of a quartz plate on one side of the stepped chamber array, and the graphene film is laser-etched along each stepped chamber to obtain a graphene absorption layer that matches the opening size of the stepped chamber. Remove excess graphene film; use a pin to assemble the graphene absorption layer onto the step surface of each step chamber to obtain a semi-finished component; A chromium / aluminum thin film was deposited on one side of the flexible strain layer by magnetron sputtering to form a film-side electrode layer; The side of the flexible strain layer electrode layer is attached tightly to the K9 flat glass, and then the other side of the flexible strain layer is subjected to plasma treatment in a plasma cleaning machine. K9 flat glass with a flexible strain layer attached is placed on the semi-finished component, and the side of the flexible strain layer that has been plasma treated is attached to the side of the stepped chamber array of the semi-finished component. Then, it is placed on a heating platform for hot pressing bonding, so that the flexible strain layer seals the opening of each stepped chamber. After cooling, the K9 flat glass is peeled off from the flexible strain layer. A dielectric layer is deposited on the outside of the membrane-side electrode layer, and then a lower electrode layer is deposited on the outside of the dielectric layer. The dielectric layer separates and fixes the flexible strain layer and the lower electrode layer to form a capacitor, thus completing the preparation of the graphene strain structure.

2. A graphene strained structure, characterized in that, Prepared by the preparation method according to claim 1, comprising: Structural base layer; A stepped chamber array includes several stepped chambers disposed on a structural base layer. Each stepped chamber includes an outer cavity and an inner cavity in sequence from the opening inward. The outer cavity and the inner cavity form a stepped surface, and the lateral dimension of the outer cavity is larger than that of the inner cavity. A graphene absorption layer is disposed on the step surface of each of the stepped chambers, and the size of the graphene absorption layer matches the opening of the stepped chamber. A flexible strain layer is attached to the outside of the stepped chamber array and seals the opening of each stepped chamber; a film-side electrode layer is deposited on the side of the flexible strain layer facing away from the stepped chamber. A dielectric layer, wherein the dielectric layer is disposed on the outer side of the film-side electrode layer; A lower electrode layer is disposed on the outside of the dielectric layer. The dielectric layer separates and fixes the flexible strain layer from the lower electrode layer, so that the film-side electrode layer and the lower electrode layer constitute a capacitor.

3. The graphene strained structure according to claim 2, characterized in that, The structural substrate layer includes a quartz plate, a germanium glass plate, a sapphire glass plate, or a silicon-based plate; the dielectric layer is PE / alumina, and the lower electrode layer is ITO glass.

4. The graphene strained structure according to claim 2, characterized in that, The stepped chamber includes a circular stepped chamber, a rectangular stepped chamber, a triangular stepped chamber, or a pentagonal stepped chamber.

5. The graphene strained structure according to claim 2, characterized in that, The film-side electrode layer includes a chromium / aluminum thin film, a chromium / copper thin film, a chromium / silver thin film, or a chromium / gold thin film.

6. The graphene strained structure according to claim 2, characterized in that, The thickness of the graphene absorption layer is not less than 5 μm.

7. The graphene strained structure according to claim 2, characterized in that, The depth of the stepped chamber is not less than 400 μm.

8. The graphene strained structure according to claim 2, characterized in that, The flexible strain layer is PDMS, and its thickness is no more than 40 μm.

9. The graphene strained structure according to claim 2, characterized in that, The graphene absorption layer has a multi-layer stacked structure, consisting of several graphene films stacked one on top of another.

10. The application of the graphene strain structure according to any one of claims 2-9 in broadband electromagnetic energy detection.

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