Graphene-perovskite bimodal sensor for eye monitoring and manufacturing method thereof

Abstract

The invention provides a graphene-perovskite dual-mode sensor for eye health monitoring and a manufacturing method of the graphene-perovskite dual-mode sensor. The sensor comprises a substrate (10); the graphene (20) is arranged on one side of the substrate (10); the isolation part (30) is arranged on one side of the graphene (20), the isolation part (30) and the substrate (10) clamp the graphene (20) together, a through hole (310) is formed in the isolation part (30), and the through hole (310) corresponds to a partial area of the graphene (20); a perovskite (40), one part of which is provided on the opposite side of the isolation part (30) from the side on which the graphene (20) is located, and the other part of which is located in the through hole (310) and is in contact with the graphene (20); and the packaging part (50) covers the perovskite (40) and the isolation part (30).

Description

Technical Field

[0001] This application relates to the field of eye monitoring technology, and in particular to a graphene-perovskite dual-modal sensor for eye health monitoring and its manufacturing method. Background Technology

[0002] Current eye fatigue and eye irradiation monitoring devices mostly rely on specialized instruments, which are inconvenient to operate and difficult to integrate into daily life. Eye fatigue monitoring mainly follows two approaches: physiological signal-based acquisition and analysis, and computer vision-based eye fatigue monitoring. Physiological signal monitoring analyzes and assesses visual fatigue by monitoring signals such as electrooculogram (EOG), electrocardiogram (ECG), electroencephalogram (EEG), and electrodermal response (EDR). This method primarily relies on interface electrodes to capture human physiological signals, offering advantages in speed and efficiency. However, the electrodes of existing sensors, when attached to the human body, cause significant inconvenience and reduce user comfort. Furthermore, the acquired biological signals may contain noise due to muscle movement, temperature changes, etc., increasing monitoring errors. Computer vision analysis for monitoring eye fatigue involves subjects wearing a monitoring device equipped with a high-speed camera. This device captures eye movements and blink frequency, analyzing the degree of eye fatigue based on the photographic images. This technology is limited by factors such as photographic shooting frequency, image resolution, and lighting conditions. Developing an accurate, sensitive, compact, lightweight, and highly comfortable eye fatigue monitoring device remains a challenge.

[0003] Regarding eye irradiation, there are currently no dosimeters for routine eye radiation monitoring. Most measurements are taken for radiation dose in radiation protection scenarios, and continuous wearable monitoring is not yet possible.

[0004] Currently, there is no wearable precision device that integrates both eye fatigue and eye irradiation monitoring functions. Summary of the Invention

[0005] To address or mitigate at least one of the technical problems mentioned in the background art, this application provides a graphene-perovskite dual-modal sensor for eye health monitoring and a method for its fabrication.

[0006] The graphene-perovskite dual-modal sensor for eye monitoring provided in this application includes: a substrate; graphene disposed on one side of the substrate; an isolation portion disposed on one side of the graphene, clamping the graphene together with the substrate, the isolation portion having a through hole corresponding to a portion of the graphene; a perovskite, partly disposed on the opposite side of the isolation portion to the side where the graphene is located, and another part located in the through hole and in contact with the graphene; and an encapsulation portion covering the perovskite and the isolation portion.

[0007] In at least one embodiment, the graphene comprises one or more serpentine graphene films.

[0008] In at least one embodiment, the area of ​​the graphene film is at least 50% of the area of ​​the substrate.

[0009] In at least one embodiment, the sensor further includes electrodes and wires connected to the graphene film.

[0010] In at least one embodiment, the perovskite includes a plurality of perovskite pixel modules that are separated from each other and arranged in an array.

[0011] In at least one embodiment, the sensor further includes electrodes and wires respectively connected to each of the perovskite pixel modules.

[0012] In at least one embodiment, the sensor is provided with only one layer of the graphene, and the perovskite pixel modules in the perovskite do not overlap in the projection direction perpendicular to the surface of the sensor.

[0013] The method for manufacturing a graphene-perovskite dual-modal sensor for eye monitoring provided in this application includes: preparing a substrate; depositing graphene on the substrate; depositing an isolation portion with through holes on the graphene, such that the isolation portion and the substrate clamp the graphene; depositing perovskite on the opposite side of the isolation portion where the graphene is located, such that a portion of the perovskite is located in the through holes and in contact with the graphene; and depositing an encapsulation portion on the perovskite.

[0014] In at least one embodiment, the manufacturing method is used to manufacture the aforementioned graphene-perovskite dual-modal sensor for eye monitoring.

[0015] In at least one embodiment, the perovskite is set by nanoimprinting.

[0016] This application's non-invasive design offers the advantages of easy application and rapid removal, significantly improving the convenience and comfort of the monitoring process and providing effective theoretical and technical support for daily eye health monitoring. The coexistence of a coupling region forming a graphene-perovskite heterostructure and a decoupling region without heterostructure formation combines the high precision and sensitivity of the coupling region with the non-interference between optical and mechanical signals in the decoupling region, thus meeting the requirements for simultaneous dual-modal monitoring of eye fatigue and eye irradiation. Attached Figure Description

[0017] Figure 1 An exploded view of a graphene-perovskite dual-modal sensor for eye health monitoring according to an embodiment of this application is shown.

[0018] Figure 2A schematic diagram of the substrate and graphene structure of a graphene-perovskite dual-modal sensor for eye health monitoring according to an embodiment of this application is shown.

[0019] Figure 3 A schematic diagram of the substrate, graphene, and isolation portion of a graphene-perovskite dual-modal sensor for eye health monitoring according to an embodiment of this application is shown.

[0020] Figure 4 A schematic diagram of the substrate, graphene, isolation portion, and perovskite structure of a graphene-perovskite dual-modal sensor for eye health monitoring according to an embodiment of this application is shown.

[0021] Figure 5 A schematic diagram of the structure of a graphene-perovskite dual-modal sensor for eye health monitoring according to an embodiment of this application is shown.

[0022] Figure 6 A schematic diagram illustrating an application scenario of a graphene-perovskite dual-modal sensor for eye health monitoring according to an embodiment of this application is shown.

[0023] Explanation of reference numerals in the attached figures

[0024] 10. Base;

[0025] 20. Graphene;

[0026] 210 Graphene film;

[0027] 30. Isolation Department;

[0028] 310 through hole;

[0029] 40. Perovskite;

[0030] 410 perovskite pixel module;

[0031] 50 Packaging Section;

[0032] 60 Skin Adhesion Site Detailed Implementation

[0033] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaustively describe all possible methods of this application, nor to limit the scope of this application.

[0034] This application provides a graphene-perovskite dual-modal sensor (hereinafter, sometimes referred to as the sensor) for eye monitoring and a method for manufacturing the same.

[0035] See Figure 1The sensor may include a substrate 10, graphene 20, an isolation part 30, a perovskite 40, and an encapsulation part 50.

[0036] See Figure 2 Graphene 20 is disposed on one side (e.g., the upper side) of the substrate 10. The material in graphene 20 is graphene or mainly comprises graphene.

[0037] See Figure 3 An isolation portion 30 is disposed on one side of the graphene 20 and clamps the graphene 20 together with the substrate 10. A through-hole 310 is formed in the isolation portion 30, and the through-hole 310 corresponds to a portion of the graphene 20. For example, the material of the isolation portion 30 can be an insulating material.

[0038] See Figure 4 A portion of the perovskite 40 is disposed on the opposite side of the graphene 20 in the isolation section 30, while another portion is located in the through-hole 310 and in contact with the graphene 20, to form a graphene-perovskite heterojunction. The ordered lattice arrangement of graphene provides uniform and ordered sites for perovskite growth, and graphene neutralizes perovskite surface defects through charge transfer, which helps reduce the surface defect concentration and achieve better interlayer coupling. The material of perovskite 40 is perovskite or mainly comprises perovskite.

[0039] See Figure 5 The encapsulation portion 50 covers the perovskite 40 and the isolation portion 30. Exemplarily, the materials of the substrate 10 and the encapsulation portion 50 may be polydimethylsiloxane (PDMS).

[0040] See Figure 6 The sensor can be integrated into the skin attachment portion 60 and can be attached to the lower eyelid area or other areas. Compared with existing complex invasive monitoring methods such as contact lenses, the non-invasive design of this application has the advantages of being able to be applied and removed at any time, greatly improving the convenience and comfort of the monitoring process and providing effective technical support for daily eye health monitoring.

[0041] Sensors attached around the eyelids produce different strains in response to eye movement and eyelid stretching. Graphene, with its excellent mechanical tensile properties, exhibits corresponding strain under stress, allowing it to sense the mechanical changes in the eyelids caused by eye movements and thus monitor eye fatigue. Signals can be transmitted via, for example, a Bluetooth module, and algorithms can analyze the data to determine the corresponding eye and eyelid movements and the degree of eye fatigue.

[0042] Perovskite materials can detect light intensity, especially due to their excellent absorption characteristics for ultraviolet and blue light. Upon detecting light irradiation, they can send back corresponding signals. Data signals can also be transmitted in real time via Bluetooth, and the corresponding irradiation intensity can be calculated using a neural network algorithm. Lead-free perovskites, such as cesium silver bismuth bromide (Cs₂AgBiBr₆), can be selected.

[0043] Depending on whether a heterojunction is formed (whether the perovskite is coupled to graphene), the sensor can be divided into coupling regions (e.g., Figure 4 The area outlined by the dashed line) and the decoupling area ( Figure 4 (The area outside the dashed box).

[0044] In the decoupling region, perovskite 40 and graphene 20 are separated by isolation part 30, and the two work independently. Perovskite 40 only responds to light, and graphene 20 only responds to mechanical strain, avoiding mutual interference between the two types of signals, which is conducive to obtaining pure mechanical and optical signals.

[0045] In the coupling region, taking common perovskites such as Cs2AgBiBr6 as an example, they form heterojunctions through direct contact with graphene. The construction of heterojunctions reduces the recombination probability of charge carriers and provides graphene channels with higher mobility for photogenerated electrons, which can effectively improve the accuracy of photodetection and the speed of photoresponse.

[0046] On the one hand, heterojunctions reduce the recombination probability of photogenerated electrons in the perovskite bulk phase or interface defects, thus improving the accuracy of photodetection. Firstly, photogenerated carriers are injected into graphene under the influence of a built-in electric field, promoting electron-hole separation and reducing carrier recombination in the bulk phase. When perovskite and graphene form an interface, their Fermi levels tend to align due to their different work functions. To achieve energy level matching, electrons flow from the graphene side (lower work function) to the perovskite side (higher work function), causing band bending at the interface and generating a built-in electric field pointing positively from graphene to perovskite. After the perovskite absorbs photons, bulk electrons are excited and transition to the conduction band, forming a large number of photogenerated electron-hole pairs. Due to the presence of the built-in electric field, and the fact that the energy of photogenerated electrons in the conduction band is higher than the Fermi level of graphene, driven by both the electric field and the energy level difference, photogenerated electrons in perovskite tend to inject into graphene, while holes remain in the perovskite. This phenomenon reduces the retention of photogenerated electrons in the perovskite, lowering the probability of recombination between photogenerated electrons and holes in the perovskite bulk phase. This extends the lifetime of photogenerated carriers, allowing more photogenerated electrons to successfully reach the electrodes, thus improving photodetection accuracy. Secondly, graphene reduces the concentration of defect states on the perovskite surface, preventing carrier recombination caused by interface defects. Defect states on the perovskite grain surface trap carriers, reducing photogenerated carrier lifetime and increasing background noise. Graphene forms weak van der Waals contacts with perovskite, without introducing new chemical bonds, and does not generate a large number of new interface states. Simultaneously, graphene neutralizes some defects at the interface through charge transfer, reducing defect concentration and decreasing the possibility of photogenerated carriers being trapped by interface defects, thereby extending the photogenerated carrier lifetime and improving photodetection accuracy.

[0047] On the other hand, the heterojunction allows for the rapid injection of photogenerated electrons from perovskite into graphene, which has a higher mobility, thus improving the photoresponse speed. Graphene possesses an electron mobility far exceeding that of perovskite, often reaching 10-1. 4 cm 2 / V·s and above. Compared to migration in the perovskite phase, photogenerated carriers migrate much faster in graphene. The heterojunction allows photogenerated carriers generated by the perovskite to be directly injected into the graphene layer immediately below, where they migrate rapidly without having to travel at a lower mobility in the perovskite phase, thus greatly improving the photoresponse speed of the device.

[0048] Because photogenerated carriers from perovskite can be injected into graphene and modulate its conductivity, a mixed signal resulting from the superposition of optical and mechanical information inputs is generated in the heterojunction. Furthermore, this mixed signal can be decoupled to separate the optical and mechanical information. For example, by comparing the signal responses in adjacent coupling and decoupling regions, the mixed signal can be split into optical and mechanical components. More specifically, a Long Short-Term Memory (LSTM) network can be used to separate the optical and mechanical signals in the coupling region. The time-series data from the coupling and decoupling regions are normalized and divided into training, validation, and test sets. An LSTM model is designed; after inputting the coupling signal, the optical and mechanical signal features are extracted through LSTM layers. The extracted feature vectors are input into a fully connected layer for regression, and the separated optical and mechanical signals are output. The model is trained and its parameters optimized using data from the coupling and decoupling regions. Inputting newly acquired coupling signals into the model allows for the separation of the optical and mechanical signal components.

[0049] In summary, the coexistence of the coupling region forming a heterojunction and the decoupling region not forming a heterojunction combines the high precision and high sensitivity of the coupling region with the non-interference of optical and mechanical signals in the decoupling region, thus meeting the requirements for simultaneous dual-modal monitoring of eye fatigue and eye irradiation.

[0050] Understandable. Figure 4 The setting area of ​​the through hole 310 in the example is only for reference; the setting area can be much larger.

[0051] When in use, graphene 20 can be placed closer to the skin than perovskite 40, making it easier for graphene 20 to sense strain in the eyelid area and for perovskite 40 to sense external light.

[0052] In some implementations, see Figure 2 The graphene 20 includes one or more (e.g., three) serpentine graphene films 210. Compared to planar films (continuous films), setting the graphene film 210 in a serpentine shape has the following two advantages: First, it can improve the structure's tolerance to strain, thereby improving the device's flexibility and tensile strength; second, it can enhance the monitoring sensitivity of local signals, avoid signal averaging by continuous films, and achieve higher spatial resolution.

[0053] In some implementations, see Figure 2 On the surface of substrate 10, the area of ​​graphene film 210 occupies at least 50% of the area of ​​substrate 10. The large-area, dense distribution of graphene film 210 facilitates full contact with the skin around the eye, enabling complete and continuous monitoring and timely response to strain. It should be understood that... Figure 2 This is for illustrative purposes only and is not intended to limit the specific size of the graphene film. The area ratio of the graphene film 210 can also be adjusted accordingly.

[0054] In some embodiments, the sensor also includes electrodes and wires (not shown) connected to the graphene film 210 for transmitting signals output by the graphene film 210 to other components such as a Bluetooth module.

[0055] In some embodiments, the perovskite 40 includes multiple perovskite pixel modules 410 that are separated from each other and arranged in an array. This pixel-array arrangement has the following advantages: First, it improves spatial resolution. The signal monitored by each pixel can be read out individually, which also facilitates the decoupling of signals from the perovskite pixel modules 410 coupled to graphene, thereby improving the overall spatial resolution. Second, it improves mechanical compatibility. The mechanical ductility of perovskite materials is far less than that of graphene, making them more sensitive to deformation. Therefore, a small-sized discrete array can reduce cracking caused by continuous large-area stress on the device. The gaps between pixels help release stress, improving the compatibility between the perovskite and graphene structures. Third, it avoids crosstalk. Each pixel is an independent photodetector, which avoids interference caused by photon scattering in a continuous thin film.

[0056] In some embodiments, the sensor also includes electrodes and wires (not shown) respectively connected to each perovskite pixel module 410, for transmitting signals output by the perovskite pixel module 410 to other components such as a Bluetooth module.

[0057] In some embodiments, the graphene 20 disposed on the sensor is only one layer. Furthermore, the perovskite pixel modules 410 in the perovskite 40 do not overlap in the projection direction perpendicular to the front surface of the sensor. Macroscopically, the perovskite 40 disposed on the sensor is also only one layer (here, the perovskite on the isolation portion 30 and the perovskite on the graphene 20 are considered the same layer). Compared to the staggered arrangement of multiple layers of graphene 20 and multiple layers of perovskite 40, the design of this application with only one layer of graphene 20 and one layer of perovskite 40 provides better sensing effects for stress and light signals, and the packaging difficulty is relatively lower.

[0058] The method for manufacturing a graphene-perovskite dual-modal sensor for eye monitoring provided in this application is used to manufacture the aforementioned sensor.

[0059] In some embodiments, the manufacturing method may include: (S1) preparing a substrate 10; (S2) depositing graphene 20 on the substrate 10; (S3) depositing an isolation portion 30 having a through hole 310 on the graphene 20, such that the isolation portion 30 and the substrate 10 clamp the graphene 20; (S4) depositing a perovskite 40 on the opposite side of the isolation portion 30 from the side where the graphene 20 is located, such that a portion of the perovskite 40 is located in the through hole 310 and in contact with the graphene 20; (S5) depositing an encapsulation portion 50 on the perovskite 40.

[0060] More specifically, for (S1), a substrate 10 of PDMS material can be prepared.

[0061] For (S2), graphene 20 can be set by inkjet printing. For example, graphene nanosheets are prepared into a homogeneous dispersion, and the graphene dispersion is printed and positioned on the substrate 10 using a high-precision inkjet printing device. After annealing, a graphic graphene pattern can be obtained.

[0062] For (S3), the isolation portion 30 can be set by deposition, and the material of the isolation portion 30 is not deposited in some areas, so that the isolation portion 30 has through holes 310.

[0063] For (S4), a perovskite pixel module 410 can be set on one side of the isolation part 30 by nanoimprinting, so that a part of the perovskite pixel module 410 is located on the isolation part 30, and another part of the perovskite pixel module 410 is located in the through hole 310 and in contact with the graphene to form a heterojunction.

[0064] For (S5), a PDMS material encapsulation section 50 can be provided to encapsulate and protect the aforementioned components.

[0065] In addition, in the above steps, for example before setting the graphene 20 and the perovskite 40, wires and electrodes can be set for the graphene film 210 and the perovskite pixel module 410 respectively, so as to capture the corresponding stress signals and optical signals and output them in the form of electrical signals.

[0066] Traditional methods for constructing heterojunctions (mechanical transfer, solution growth, vapor deposition, etc.) often result in graphene-perovskite interface mismatch, leading to interfacial stress concentration and significant exciton recombination. This application utilizes nanoimprinting to improve perovskite pattern quality and directly imprints perovskite onto the graphene layer surface, thus enhancing interface matching to some extent. Furthermore, the nanoimprinting technology used in this application offers high throughput advantages, and the imprinting equipment allows for precise control of imprinting parameters such as pressure, time, and temperature, enabling high-efficiency fabrication while maintaining heterojunction interface quality, which is beneficial for the industrial application of this technology.

[0067] The above are preferred embodiments of this application. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A graphene-perovskite dual-modal sensor for eye monitoring, characterized in that, include: Base (10); Graphene (20) is disposed on one side of the substrate (10); An isolation portion (30) is disposed on one side of the graphene (20) and clamps the graphene (20) together with the substrate (10). A through hole (310) is provided in the isolation portion (30), and the through hole (310) corresponds to a part of the graphene (20). The perovskite (40) has a portion disposed on the opposite side of the graphene (20) in the isolation portion (30), and another portion is located in the through hole (310) and in contact with the graphene (20). The encapsulation portion (50) covers the perovskite (40) and the isolation portion (30).

2. The graphene-perovskite dual-modal sensor for eye monitoring according to claim 1, characterized in that, The graphene (20) includes one or more serpentine graphene films (210).

3. The graphene-perovskite dual-modal sensor for eye monitoring according to claim 2, characterized in that, The area of ​​the graphene film (210) is at least 50% of the area of ​​the substrate (10).

4. The graphene-perovskite dual-modal sensor for eye monitoring according to claim 2, characterized in that, It also includes electrodes and wires connected to the graphene film (210).

5. The graphene-perovskite dual-modal sensor for eye monitoring according to claim 1, characterized in that, The perovskite (40) includes a plurality of perovskite pixel modules (410) that are separated from each other and arranged in an array.

6. The graphene-perovskite dual-modal sensor for eye monitoring according to claim 5, characterized in that, It also includes electrodes and wires respectively connected to each of the perovskite pixel modules (410).

7. The graphene-perovskite dual-modal sensor for eye monitoring according to claim 1, characterized in that, The sensor has only one layer of graphene (20), and the perovskite pixel modules (410) in the perovskite (40) do not overlap in the projection direction perpendicular to the surface of the sensor.

8. A method for manufacturing a graphene-perovskite dual-modal sensor for eye monitoring, characterized in that, The manufacturing method includes: Prepare the substrate (10); Graphene (20) is disposed on the substrate (10); An isolation portion (30) with a through hole (310) is provided on the graphene (20) such that the isolation portion (30) and the substrate (10) clamp the graphene (20). A perovskite (40) is disposed on the opposite side of the graphene (20) in the isolation section (30), and a portion of the perovskite (40) is located in the through hole (310) and in contact with the graphene (20). An encapsulation portion (50) is provided on the perovskite (40).

9. The method for manufacturing a graphene-perovskite dual-modal sensor for eye monitoring according to claim 8, characterized in that, Used to manufacture the graphene-perovskite dual-modal sensor for eye monitoring as described in any one of claims 2 to 7.

10. The method for manufacturing a graphene-perovskite dual-modal sensor for eye monitoring according to claim 8, characterized in that, The perovskite (40) was set by nanoimprinting.

Images