Eye electrophysiological signal acquisition sensor and preparation method thereof

Abstract

The invention relates to the technical field of biomedical sensors, in particular to an eye electrophysiological signal acquisition sensor and a preparation method thereof.The eye electrophysiological signal acquisition sensor is of an aspheric curved surface structure and comprises a flexible substrate layer and a conductive functional layer which are sequentially stacked from outside to inside; the conductive function layer is a continuous conductive film. According to the eye electrophysiological signal acquisition sensor provided by the invention, an aspheric curved surface structure is constructed by imitating the corneal curvature, so that the sensor is soft, light and thin, and mechanical compression is avoided; the conductive functional layer capable of covering the complete cornea area is arranged in the flexible substrate layer, so that the conductive functional layer can continuously cover the cornea central area, the electrode-cornea contact area is increased, the contact impedance is reduced, the signal acquisition efficiency is improved, the signal acquisition stability is ensured, and the advantages of high signal quality and high stability are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical sensors, and in particular to an eye electrophysiological signal acquisition sensor and a preparation method thereof. Background Art

[0002] Ocular electrophysiological signals, particularly the electroretinogram (ERG), a noninvasive bioelectrical signal used to assess the functional status of the visual system, have been widely used in clinical eye disease diagnosis and animal model research. Traditional ERG detection methods typically rely on rigid structures such as wire electrodes and corneal ring electrodes. These electrodes require eyelid splinters, anesthetics, or physical compression for fixation, resulting in poor wearing comfort, significant signal interference, and unsuitability for small animal models.

[0003] In recent years, with the development of flexible electronics, some researchers have begun exploring corneal-attached sensors based on flexible materials to improve signal stability and ease of use. However, existing flexible electrodes mostly use localized conductive structures or linear sensing units, which have limited conductive areas and affect signal acquisition efficiency.

[0004] In view of this, how to improve the signal acquisition efficiency of cornea-attached sensors is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] In order to solve the problem of low signal acquisition efficiency of corneal-attached sensors in the prior art, the present invention provides an ocular electrophysiological signal acquisition sensor, which is composed of a flexible base layer, a hydrogel intermediate layer and a conductive functional layer stacked in sequence. It has good surface conformability, biological flexibility and signal stability, and high signal acquisition efficiency, thereby solving the problem of low signal acquisition efficiency of corneal-attached sensors in the prior art.

[0006] The technical solution adopted by the present invention to solve its technical problem is: A sensor for collecting electrophysiological signals of the eye has an aspherical curved surface structure and comprises a flexible base layer and a conductive functional layer stacked sequentially from the outside to the inside; the conductive functional layer is a continuous conductive film.

[0007] Optionally, the curvature radius of the flexible base layer is 7.16-7.17 mm.

[0008] Optionally, the thickness of the central area of ​​the flexible base layer is 0.1 mm.

[0009] Optionally, the thickness of the edge region of the flexible base layer is 0.12 mm.

[0010] Optionally, the material of the flexible base layer is polydimethylsiloxane.

[0011] Optionally, the material of the conductive functional layer is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate.

[0012] Optionally, a hydrogel layer is further included and is arranged between the flexible substrate layer and the conductive functional layer.

[0013] Optionally, the material of the hydrogel layer is polyvinyl alcohol or hydroxyethyl methacrylate.

[0014] Another object of the present invention is to provide a method for preparing the above-mentioned ocular electrophysiological signal acquisition sensor, comprising the following steps: S1: After mixing PDMS with a curing agent, the mixture is placed in an aspheric surface mold for degassing and curing to obtain a flexible base layer; S2: Using poly(3,4-ethylenedioxythiophene):polystyrene sulfonate) as raw material, a conductive layer is deposited on the surface of the flexible base layer by spin spraying to obtain a conductive functional layer.

[0015] Optionally, before step S2, the method further includes: preparing a hydrogel layer on the surface of the flexible base layer.

[0016] The beneficial effects of the present invention are: The ocular electrophysiological signal acquisition sensor provided by the present invention has an aspheric surface structure constructed in accordance with the corneal curvature, which is soft, light and thin, and avoids mechanical pressure. By arranging a conductive functional layer capable of covering the entire corneal area within the flexible base layer, the conductive functional layer can continuously cover the central area of ​​the cornea, thereby increasing the electrode-corneal contact area and reducing the contact impedance. While improving the signal acquisition efficiency, it ensures the stability of the collected signal, and has the advantages of high signal quality and strong stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings and examples.

[0018] Figure 1 This is a simplified structural diagram of the eye electrophysiological signal acquisition sensor of the present invention; Figure 2 This is an exploded view of the ocular electrophysiological signal acquisition sensor of the present invention; Figure 3 This is a physical photo of the PPCL device in the present invention; Figure 4 This is a photo of the PPCL of the present invention being worn on the surface of the rabbit cornea; Figure 5 Schematic diagram of the effect of spray pressure on sensor impedance and transmittance in the present invention; Figure 6 Schematic diagram showing the effect of spraying times on sensor impedance and transmittance in the present invention; Figure 7 Schematic diagram of the effect of single spraying time on sensor impedance and transmittance in the present invention; Figure 8 is the stress-strain (σ-ε) curve of PDCL, PPCL, and HPCL in the present invention; Figure 9 is the static water contact angle of the PDCL prepared in Example 14 of the present invention; Figure 10 is the static water contact angle of the PPCL prepared in Example 1 of the present invention; Figure 11 is the static water contact angle of the HPCL prepared in Example 15 of the present invention; Figure 12 is a cross-sectional image of the conductive functional layer in the PDCL prepared in Example 14 of the present invention; Figure 13 This is a picture of the human-mechanical interference test device of the present invention; Figure 14 is the impedance change of the PPCL prepared in Example 1 of the present invention under mechanical disturbance; Figure 15 PPCL step bending test diagram prepared in Example 1 of the present invention; Figure 16 The impedance change during the step bending process of the PPCL prepared in Example 1 of the present invention; Figure 17 The PPCL functional area prepared in Example 1 of the present invention is folded to a test state of 2mm FIG; Figure 18 is the impedance change of the PPCL prepared in Example 1 of the present invention under cyclic bending; Figure 19 This is the ERG waveform of PDCL, PPCL, and HPCL in the healthy rabbit model of the present invention; Figure 20 These are the ERG signal waveforms recorded using PPCL, Jet, and DTL in the same animal model; Figure 21 yes Figure 20 The average amplitude and latency of each ERG test condition; Figure 22 This is the ERG waveform recorded using PPCL and Jet sensor in a pathological model.

[0019] In the figure: 1-flexible base layer; 2-conductive functional layer; 3-hydrogel layer; 4-external wiring element. DETAILED DESCRIPTION

[0020] The present invention will now be described in further detail. The embodiments described below are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0021] In order to solve the problem of low signal acquisition efficiency of corneal-attached sensors in the prior art, the present invention provides an eye electrophysiological signal acquisition sensor, see Figure 1 、 Figure 2 As shown, the sensor as a whole has an aspheric curved surface structure, similar to the configuration of a contact lens, so that the sensor can naturally fit on the surface of the eyeball; the eye electrophysiological signal acquisition sensor includes a flexible base layer 1 and a conductive functional layer 2 stacked in sequence from the outside to the inside; by introducing the flexible base layer 1, the eye electrophysiological signal acquisition sensor is given excellent flexibility and biocompatibility, thereby improving the fit and comfort of the eye electrophysiological signal acquisition sensor to the cornea; in order to improve the signal acquisition efficiency, the present invention preferably configures the conductive functional layer 2 to be a continuous conductive film, so that the conductive functional layer 2 can completely cover the corneal area during wearing, thereby increasing the signal collection area and enhancing the stability of signal collection.

[0022] Specifically, the "outside" in the present invention refers to the side of the eye electrophysiological signal acquisition sensor that is away from the eyeball during wearing; on the contrary, the "inside" refers to the side of the eye electrophysiological signal acquisition sensor that is close to the eyeball during wearing.

[0023] The eye electrophysiological signal acquisition sensor provided by the present invention has an aspheric surface structure constructed in accordance with the corneal curvature, which is soft, light and thin, and avoids mechanical pressure. By arranging a conductive functional layer 2 capable of covering the entire corneal area within the flexible base layer 1, the conductive functional layer 2 can continuously cover the central area of ​​the cornea, thereby increasing the electrode-corneal contact area and reducing the contact impedance. While improving the signal acquisition efficiency, it ensures the stability of the collected signal, and has the advantages of high signal quality and strong stability.

[0024] Existing flexible electrodes mostly use local conductive structures or linear sensing units, which not only have limited conductive areas but also poor wearing comfort. Based on this, the present invention uses a flexible base layer 1 as a carrier and introduces a conductive functional layer 2 in the form of a continuous conductive film. While improving the signal acquisition efficiency and stability, the flexible curved surface structure and full-fit design achieve non-invasive signal acquisition and recording with naturally closed eyes.

[0025] To ensure fit with the cornea, the present invention preferably has a curvature radius of 7.16-7.17 mm, and further preferably has a diameter of 11.6 mm, a thickness of 0.1 mm in the central area of ​​the flexible base layer 1, and a thickness of 0.12 mm in the edge area of ​​the flexible base layer 1, so that it has a curvature that matches the corneal surface, and is used to match the corneal surface morphology and provide structural support.

[0026] Furthermore, based on the fact that the eye electrophysiological signal acquisition sensor provided by the present invention is suitable for non-invasive signal acquisition, in order to avoid the impact of poor transparency and insufficient light transmittance on visual clarity and normal imaging, the present invention preferably uses polydimethylsiloxane (PDMS) as the material of the flexible base layer 1, and utilizes the high light transmittance of PDMS to improve the light transmittance of the flexible base layer 1. It is further preferred that the light transmittance of the central light zone of the flexible base layer 1 is greater than 65%, so that it has good transparency, flexibility and biocompatibility at the same time.

[0027] Specifically, the materials currently commonly used in corneal contact lenses include polyvinyl alcohol (PVA), polydimethylsiloxane (PDMS), and hydroxyethyl methacrylate (HEMA) hydrogels. Although PVA has good wearing comfort and initial biocompatibility, it is prone to water swelling in the body fluid environment, resulting in structural instability and decreased mechanical properties. If used in electrophysiological signal acquisition sensors, it is easy to cause unstable collected signals. HEMA hydrogel is widely used in daily corneal contact lens products due to its excellent hydration ability and soft properties. However, HEMA has strong water absorption and a high expansion rate (>10%). When used as a supporting substrate for transparent conductive coatings, its swelling deformation can easily cause interfacial delamination or coating rupture, affecting the structural integrity of the sensor and signal stability.

[0028] Based on this, the present invention selects PDMS with moderate mechanical modulus, excellent oxygen permeability, bioinertness and wide process compatibility as the supporting substrate of the conductive coating to improve the stability of signal acquisition while ensuring good transparency, flexibility and biocompatibility.

[0029] To achieve real-time acquisition of high-quality ERG signals, the present invention preferably uses poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) as the material of the conductive functional layer 2, and further preferably uses PEDOT:PSS purchased from Shenzhen Yilai Technology Co., Ltd.

[0030] Because the sensor provided by the present invention is used for noninvasive signal acquisition, the conductive functional layer 2 must simultaneously possess transparency, conductivity, and biocompatibility. Currently, commonly used transparent conductive materials include indium tin oxide (ITO), silver nanowires (AgNWs), carbon nanotubes (CNTs), graphene, and MXene. While ITO offers high transmittance (>80%) and good conductivity, it is also brittle and poorly flexible, prone to cracking when bent, making it difficult to use in flexible devices operating in high-strain environments. AgNWs offer good conductivity and a degree of flexibility, but their optical transmittance decreases at high concentrations, and they are prone to nanowire aggregation, affecting surface uniformity and optical consistency. CNTs offer excellent conductivity, but their poor dispersibility in aqueous solutions can easily lead to film inhomogeneities. While graphene and MXene possess excellent two-dimensional conductive properties, high-quality graphene is expensive to prepare and requires complex film-forming processes. MXene is extremely sensitive to water and oxygen, prone to oxidative degradation, and lacks stability.

[0031] Based on this, the present invention adopts PEDOT:PSS as the material of the conductive functional layer 2, taking advantage of the characteristics of PEDOT:PSS that have excellent conductivity, transparency, flexibility and biocompatibility, and is easy to achieve large-area continuous thin film preparation, so that the prepared conductive functional layer 2 does not affect the transparency and comfort of wearing while improving the signal collection efficiency.

[0032] In order to improve wearing comfort and enhance interface bonding strength, the present invention preferably includes the ocular electrophysiological signal acquisition sensor further comprising a hydrogel layer 3 disposed between the flexible base layer 1 and the conductive functional layer 2 .

[0033] The hydrogel layer 3 is a continuous layer covering the inner side of the flexible base layer 1. In the present invention, the preferred material of the hydrogel layer 3 is polyvinyl alcohol (PVA) or hydroxyethyl methacrylate (HEMA), which can be selected according to the device type to take into account both wearing comfort and improvement of interface bonding stability.

[0034] For example, in practical applications, the device of the present invention can be divided into three specific structural forms according to the different intermediate hydrogel materials: 1) PDCL (PEDOT:PSS-Coated Lens based on PDMS): A conductive functional layer 2 made of PEDOT:PSS is directly placed on a flexible substrate layer 1 made of PDMS. 2) PPCL (PEDOT:PSS-Coated Lens with PVA interlayer): A PVA hydrogel layer 3 is pre-formed on a flexible PDMS substrate 1, and a conductive functional layer 2 made of PEDOT:PSS is then placed on the hydrogel layer 3. Ÿ3) HPCL (PEDOT:PSS-Coated Lens with HEMA interlayer): HEMA is used as the hydrogel layer 3, and the rest of the structure is the same as PPCL.

[0035] Among them, the PPCL structure is the best in terms of wearing stability, signal quality and animal test performance. Figure 3 and Figure 4 PPCL is used as an example for physical display and experimental description.

[0036] For details, see Figure 3 As shown in the figure, this is a real photo of the PPCL device; since the appearance of the above three structural forms is basically the same, for the sake of simplicity and representativeness, only the real photo of PPCL is shown here; Figure 4 As shown in the figure, the PPCL device can be naturally attached to the surface of the rabbit cornea without affecting its normal blinking and natural eye closure, showing excellent bioadaptability and comfort, supporting ERG acquisition in the natural closed eye state without an eyelid speculum, and effectively improving animal comfort and data quality.

[0037] Furthermore, to facilitate signal collection, the ocular electrophysiological signal collection sensor provided by the present invention is provided with an external wiring element 4, which is located at the edge of the device and can be treated with silver paste (silver coating) to connect to the signal output system.

[0038] Traditional rigid electrodes are not suitable for ERG detection in small animals. The eye electrophysiological signal acquisition sensor provided by the present invention is small, light and thin, easy to stably record in animal experiments, and reduces interference. The eye electrophysiological signal acquisition sensor provided by the present invention has a reasonable structure, strong fit, excellent conductivity, biocompatibility and optical transparency, and can be non-invasively and stably attached to the corneal surface to achieve real-time acquisition of high-quality ERG signals.

[0039] The ocular electrophysiological signal acquisition sensor provided by this invention is a disposable adhesive design that can be non-invasively attached to the corneal surface through gentle pressure, without the need for additional fixing devices. This device can be used to record full-field electroretinogram (ff-ERG) signals according to the International Society for Clinical Electrophysiology of Vision (ISCEV) standard, including dark-adapted ERG, light-adapted ERG, oscillatory potentials, and 30Hz light ERG, suitable for ocular function assessment in healthy and pathological animal models. In animal experiments, the device can record ERGs in the naturally closed eye state without the need for an eyelid speculum, achieving non-invasive ocular biosignal acquisition and significantly reducing signal interference caused by eyelid manipulation.

[0040] The three-layer structure of the eye electrophysiological signal acquisition sensor provided by the present invention has an overall curved surface fitting configuration. The aspheric surface parameters can be customized by replacing the mold. The base curve radius and lens thickness can be adjusted according to the corneal characteristics of different animals or people to adapt to the geometric shape of the cornea of ​​different animals or humans; preferably, the total thickness of the three-layer structure does not exceed 150 μm, and the transmittance of the central optical zone is greater than 65% to ensure imaging clarity and light stimulus response quality.

[0041] The ocular electrophysiological signal acquisition sensor provided by the present invention has a wearing comfort comparable to that of conventional corneal contact lenses, and is suitable for animal models or future clinical non-invasive visual function testing scenarios, especially for functional ophthalmological evaluation scenarios of animal models, providing an effective means for non-invasive, stable and repeatable visual electrophysiological testing.

[0042] Another object of the present invention is to provide a method for preparing the above-mentioned ocular electrophysiological signal acquisition sensor, the preparation method comprising the following steps: S1: After mixing PDMS with a curing agent, the mixture is placed in an aspherical curved surface mold for degassing and then cured to obtain a flexible base layer 1; Specifically, commercially available PDMS and a curing agent can be used in this step. In the present invention, Dow Corning's SYLGARD product is preferably used. Specifically, the preferred PDMS is Dow Corning's PDMS prepolymer SYLGARD 184, and the preferred curing agent is Dow Corning's PDMS curing agent SYLGARD 184. The main agent and the curing agent are mixed in a mass ratio of 10:1, stirred thoroughly, poured into an aspheric mold, degassed, and cured at 70°C for 3 hours. The mold is then demolded to form a transparent substrate having a target base curve (7.16-7.17 mm) and a diameter (11.6 mm). S2: Using poly(3,4-ethylenedioxythiophene):polystyrene sulfonate) as raw material, a conductive layer is deposited on the surface of the flexible substrate layer 1 by spin spraying to obtain a conductive functional layer 2.

[0043] The present invention facilitates the deposition of a continuous and uniform conductive film layer through a rotary spraying method, thereby enabling real-time collection of bioelectric signals.

[0044] Specifically, this step can use a rotary spraying platform to deposit the PEDOT:PSS conductive layer: S21: Fix the sample in the 3D printed connector and connect it to the central rotation axis; S22: Start the platform and set the speed to 1000 r / min; S23: Using poly(3,4-ethylenedioxythiophene):polystyrene sulfonate as raw material, the spraying parameters are set to a spraying pressure of 0.06-0.16 MPa, more preferably 0.08-0.12 MPa, a spraying distance of 15 cm, a spraying time of 1-9 s, more preferably 3-7 s, and a number of spraying times of 1-5 times, more preferably 2-4 times; S24: After low-temperature heating and drying, a continuous and uniform conductive functional layer 2 is formed.

[0045] The present invention uses a rotary spraying platform to achieve spray film formation to successfully prepare the conductive functional layer 2. By controlling the spraying pressure, distance, time, number of times and rotation speed (optimized parameters are: 0.08 MPa, 15 cm, 3 s, 3 times, 1000 r / min), uniform deposition of PEDOT:PSS is achieved, thereby improving the consistency and repeatability of the device.

[0046] The preparation method of the eye electrophysiological signal acquisition sensor provided by the present invention has a simple and controllable preparation process, an easy-to-operate rotary spraying platform, adjustable parameters, and good film formation consistency; the prepared eye electrophysiological signal acquisition sensor has an aspheric surface structure constructed in accordance with the corneal curvature, is soft and thin, and avoids mechanical compression; by arranging a conductive functional layer 2 capable of covering the entire corneal area within the flexible base layer 1, the conductive functional layer 2 can continuously cover the central area of ​​the cornea, thereby increasing the electrode-corneal contact area and reducing the contact impedance, thereby improving the signal acquisition efficiency while ensuring the stability of the collected signal, and has the advantages of high signal quality and strong stability.

[0047] For the sensor provided with the hydrogel layer 3 , the preparation method further comprises, before step S2 , preparing the hydrogel layer 3 on the surface of the flexible substrate layer 1 .

[0048] Specifically, the hydrogel layer 3 in the PPCL device can be prepared as follows: The flexible substrate layer 1 is completely immersed in a freeze-thawed 5wt% PVA solution. After standing for 5-10 minutes, the substrate is removed and any excess surface solution is aspirated. The substrate is then placed in a constant-temperature, forced-air drying oven at 110-120°C for 5-15 minutes to solidify the PVA coating. This step can be repeated up to three times if necessary to increase coating thickness and adhesion. The hydrogel layer 3 in the HPCL device can be prepared as follows: HEMA spray coating: 3 mL of HEMA prepolymer solution is added to a spray gun. The sensor substrate is positioned in the center of a spray turntable at a speed of 1000 rpm. A uniform spraying pressure of 0.08 MPa and a distance of 15 cm are applied in one pass. UV curing: After spraying, the substrate is immediately irradiated with a UV lamp at an intensity of 258 mW / cm² for 60 seconds to induce polymerization of HEMA on the PDMS surface, forming a dense hydrogel layer 3. The HEMA prepolymer solution is prepared as follows: Weigh 0.2 g of 819 photoinitiator and add it to a 100 mL light-shielded (tin foil-wrapped) reagent bottle. Then add 4 g of EGDMA (cross-linker) and 15.8 g of HEMA (monomer) and mix thoroughly to obtain a mixed solution. Place the mixed solution in an ultrasonic constant temperature cleaner and shake it for 30 minutes (99% power) to ensure that the photoinitiator is fully dissolved and obtain a uniform HEMA prepolymer solution.

[0049] Specifically, as described above, although PDMS has a moderate mechanical modulus, excellent oxygen permeability, bioinertness, and broad process compatibility, its surface is highly hydrophobic (contact angle of approximately 110°), which is not conducive to uniform coating adhesion in aqueous systems. Based on this, to avoid affecting its long-term stability due to weak interlayer bonding, the present invention introduces surface modification technology to improve its hydrophilicity and coating adhesion.

[0050] Specifically, the preparation method of the eye electrophysiological signal acquisition sensor provided by the present invention further includes, after obtaining the flexible base layer 1 in step S1, enhancing the surface activity of the flexible base layer 1 by oxygen plasma treatment (30s), providing interface conditions for subsequent hydrogel attachment, so that during the preparation process of the eye electrophysiological signal acquisition sensor provided by the present invention, each layer is stably composited by plasma treatment, physical intercalation or interface bonding, the overall thickness of the three-layer structure is controlled within 150μm, and the transmittance of the central optical area is higher than 65%, which can meet the luminous flux requirements of visual electrophysiological testing.

[0051] During the oxygen plasma treatment process, the flexible substrate layer 1 made of PDMS is placed in a reaction chamber and oxygen or nitrogen is introduced. A high-frequency electric field is applied to generate high-energy plasma. The active oxygen / nitrogen free radicals in the plasma react chemically with the PDMS surface, breaking the methyl structure and introducing polar functional groups such as hydroxyl (Si-OH) or amino groups, thereby increasing the surface energy, improving its hydrophilicity and the adhesion of subsequent coatings.

[0052] As described above, the ocular electrophysiological signal acquisition sensor provided by the present invention is suitable for use in animal models and future clinical non-invasive visual function testing. The device, in the form of an aspherical contact lens, consists of a flexible base layer, a hydrogel intermediate layer, and a conductive functional layer stacked from the outside inward. The flexible base layer 1 is made of polydimethylsiloxane (PDMS) and offers excellent optical transparency and biocompatibility. The intermediate layer is a hydrogel layer 2 made of polyvinyl alcohol (PVA) or hydroxyethyl methacrylate (HEMA) to enhance interfacial adhesion and wearer comfort. The conductive functional layer 3 is a PEDOT:PSS thin film, uniformly deposited on the surface of the hydrogel layer 2 via a spin-spray coating process. The three layers are stabilized by plasma treatment and physical bonding, forming a complete, fully coated conductive interface. The device exhibits excellent surface conformability, bioflexibility, and signal stability, enabling high-quality acquisition of ocular electrophysiological signals (such as ERGs) even in the naturally closed eye state without the need for an eyelid speculum. The sensor provided by the present invention boasts a novel structure, simple preparation, and excellent signal performance, offering promising application prospects.

[0053] The ocular electrophysiological signal acquisition sensor provided by the present invention is suitable for a variety of application scenarios and can be promoted and used in scenarios such as animal experiments, eye disease screening, ophthalmic diagnosis and treatment, and physiological research; it has excellent biocompatibility, reasonable material selection, avoids eye irritation and immune rejection, and supports short-term or one-time non-invasive wear; the structure is customizable, and parameters can be flexibly adjusted by replacing the mold to adapt to different usage needs.

[0054] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below.

[0055] Example 1 This embodiment provides a method for preparing an eye electrophysiological signal acquisition sensor, comprising the following steps: S1: PDMS (Dow Corning's PDMS prepolymer SYLGARD 184) and curing agent (Dow Corning's PDMS curing agent SYLGARD 184) were mixed in a mass ratio of 10:1. After thorough stirring, the mixture was poured into an aspheric mold for degassing and then cured at 70°C for 3 hours. The mold was then demolded to form a transparent substrate with a target base curve (7.16-7.17 mm) and a diameter (11.6 mm). The surface activity was enhanced by oxygen plasma treatment (30 s) to obtain a flexible substrate layer 1. The oxygen plasma treatment process was as follows: the prepared PDMS substrate was placed in a plasma cleaning machine (PDC-MG, Chengdu Mingheng Technology Development Co., Ltd.), the oxygen valve was opened, and the pressure reducing valve was adjusted to 0.1–0.2 MPa. The vacuum pump was started and the cleaning chamber was sealed. The vacuum level was reduced to approximately 8.9 × 10 -4MPa, plasma glow was started and oxygen plasma treatment was performed for 2 minutes to enhance surface activity; the thickness of the flexible substrate layer 1 in the central area was 0.1 mm, and the thickness in the edge area was 0.12 mm; S2: The flexible substrate layer 1 was completely immersed in a 5 wt% PVA solution after freeze-thaw, allowed to stand for 10 minutes, and then removed and excess solution on the surface was removed by absorbing. The flexible substrate layer 1 was then placed in a constant temperature forced air drying oven at 120°C for 10 minutes to fix the PVA coating, thereby obtaining a hydrogel layer 3. S31: Fixing the sample including the flexible substrate layer 1 and the hydrogel layer 3 in a 3D printed connector, connected to a central rotation axis; S32: Start the platform and set the speed to 1000 r / min; S33: PEDOT:PSS purchased from Shenzhen Yilai Technology Co., Ltd. was used as the raw material for rotary spray coating. The spraying parameters were set as spraying pressure 0.08 MPa, spraying distance 15 cm, spraying time 5 s, and spraying times 3 times; S34: After heating and drying at a low temperature of 60° C. for 2 hours, a continuous and uniform conductive functional layer 2 is formed to obtain an eye electrophysiological signal acquisition sensor (PPCL).

[0056] Example 2 The difference between this embodiment and embodiment 1 is that the spraying pressure in step S33 is 0.06 MPa.

[0057] Example 3 The difference between this embodiment and embodiment 1 is that the spraying pressure in step S33 is 0.10 MPa.

[0058] Example 4 The difference between this embodiment and embodiment 1 is that the spraying pressure in step S33 is 0.12 MPa.

[0059] Example 5 The difference between this embodiment and embodiment 1 is that the spraying pressure in step S33 is 0.16 MPa.

[0060] The electrical and optical properties of the eye electrophysiological signal acquisition sensors prepared in Examples 1-5 were tested, and the test results are shown in FIG. Figure 5 shown.

[0061] from Figure 5It can be seen that as the spray pressure increases, the atomized droplet size becomes smaller and the kinetic energy increases, making it easier for the PEDOT:PSS solution to form a continuous and dense conductive layer. The impedance significantly decreases from the initial 6733Ω to 87Ω, indicating that the conductive path of the coating has increased significantly and the interfacial contact resistance has decreased. However, due to the increase in material accumulation and the increase in coating thickness, the scattering and absorption of light by the coating are enhanced, and the transmittance drops from 90.4% to 49.8%. In this process, pressure has a significant impact on the morphology and thickness of the coating, which in turn affects both electrical and optical properties.

[0062] In practical sensor applications, to ensure effective transmission of light stimulation and reduce background noise, the sensor's transmittance must be higher than 65%, and its impedance must be controlled within 5kΩ. Therefore, from a comprehensive performance perspective, a spray pressure range of 0.08–0.12MPa is the ideal spray intensity range for the ocular electrophysiological signal acquisition sensor used in this invention.

[0063] Example 6 The difference between this embodiment and embodiment 3 is that the number of spraying times in step S33 is 1.

[0064] Example 7 The difference between this embodiment and embodiment 3 is that the number of spraying times in step S33 is 2.

[0065] Example 8 The difference between this embodiment and embodiment 3 is that the number of spraying times in step S33 is 4 times.

[0066] Example 9 The difference between this embodiment and embodiment 3 is that the number of spraying times in step S33 is 5 times.

[0067] The electrical and optical properties of the eye electrophysiological signal acquisition sensors prepared in Examples 3, 6-9 were tested, and the test results are shown in FIG. Figure 6 shown.

[0068] from Figure 6 As can be seen, with increasing spraying times, the number of PEDOT:PSS layers on the substrate increases, the connection density of the conductive polymer chains increases, and a more stable π-π conjugated structure is formed, which facilitates charge transfer. The coating impedance decreases from 1824Ω to 83Ω, demonstrating good electrical continuity. However, multiple sprayings may lead to loose interlayer bonding and increased interface roughness, which in turn causes a decrease in transmittance (from 76.4% to 50.1%).

[0069] In engineering implementation, the number of spraying times not only affects performance, but also directly affects preparation time and product consistency. Taking all factors into consideration, 2-4 spraying times can significantly improve conductivity without significantly sacrificing optical performance, and is the recommended spraying frequency range for this invention.

[0070] Example 10 The difference between this embodiment and embodiment 1 is that the spraying time in step S33 is 1 s.

[0071] Example 11 The difference between this embodiment and embodiment 1 is that the spraying time in step S33 is 3 seconds.

[0072] Example 12 The difference between this embodiment and embodiment 1 is that the spraying time in step S33 is 7 seconds.

[0073] Example 13 The difference between this embodiment and embodiment 1 is that the spraying time in step S33 is 9 seconds.

[0074] The electrical and optical properties of the eye electrophysiological signal acquisition sensors prepared in Examples 3, 10-13 were tested, and the test results are shown in FIG. Figure 7 shown.

[0075] Spraying time determines the amount of PEDOT:PSS solution deposited during each spraying operation. Experiments show that with increasing spraying time, the coating impedance decreases significantly (from 4938Ω to 100Ω), indicating more complete material accumulation and better coverage. However, transmittance decreases significantly with increasing thickness, from 95.4% to 45.6%. When the spraying time is less than 3 seconds, conductivity is not fully established; when it exceeds 7 seconds, the transmittance drops to a critical lower limit, affecting the optical signal's ability to reach the fundus. To balance performance and process efficiency, a single spraying time between 3 and 7 seconds is preferred.

[0076] In the present invention, a spectrophotometer (Lambda 950) is used to test the light transmittance of the sensor; and an LCR digital impedance tester is used to measure the coating impedance.

[0077] Example 14 This embodiment provides a method for preparing an eye electrophysiological signal acquisition sensor, comprising the following steps: S1: PDMS (Dow Corning's PDMS prepolymer SYLGARD 184) and curing agent (Dow Corning's PDMS curing agent SYLGARD 184) were mixed in a mass ratio of 10:1. After thorough stirring, the mixture was poured into an aspheric mold for degassing and then cured at 70°C for 3 hours. The mold was then demolded to form a transparent substrate with a target base curve (7.16-7.17 mm) and a diameter (11.6 mm). The surface activity was enhanced by oxygen plasma treatment (30 s) to obtain a flexible substrate layer 1. The oxygen plasma treatment process was as follows: the prepared PDMS substrate was placed in a plasma cleaning machine (PDC-MG, Chengdu Mingheng Technology Development Co., Ltd.), the oxygen valve was opened, and the pressure reducing valve was adjusted to 0.1–0.2 MPa. The vacuum pump was started and the cleaning chamber was sealed. The vacuum level was reduced to approximately 8.9 × 10 -4 MPa, plasma glow was started and oxygen plasma treatment was performed for 2 minutes to enhance surface activity; the thickness of the flexible substrate layer 1 in the central area was 0.1 mm, and the thickness in the edge area was 0.12 mm; S21: Fixing the sample including the flexible base layer 1 in a 3D printed connector, connected to the central rotation axis; S22: Start the platform and set the speed to 1000 r / min; S23: PEDOT:PSS purchased from Shenzhen Yilai Technology Co., Ltd. was used as the raw material for rotary spray coating. The spraying parameters were set as spraying pressure 0.08 MPa, spraying distance 15 cm, spraying time 5 s, and spraying times 3 times; S24: After heating and drying at a low temperature of 60° C. for 2 hours, a continuous and uniform conductive functional layer 2 is formed to obtain an eye electrophysiological signal acquisition sensor (PDCL).

[0078] Example 15 This embodiment provides a method for preparing an eye electrophysiological signal acquisition sensor, comprising the following steps: S1: PDMS (Dow Corning's PDMS prepolymer SYLGARD 184) and curing agent (Dow Corning's PDMS curing agent SYLGARD 184) were mixed in a mass ratio of 10:1. After thorough stirring, the mixture was poured into an aspheric mold for degassing and then cured at 70°C for 3 hours. The mold was then demolded to form a transparent substrate with a target base curve (7.16-7.17 mm) and a diameter (11.6 mm). The surface activity was enhanced by oxygen plasma treatment (30 s) to obtain a flexible substrate layer 1. The oxygen plasma treatment process was as follows: the prepared PDMS substrate was placed in a plasma cleaning machine (PDC-MG, Chengdu Mingheng Technology Development Co., Ltd.), the oxygen valve was opened, and the pressure reducing valve was adjusted to 0.1–0.2 MPa. The vacuum pump was started and the cleaning chamber was sealed. The vacuum level was reduced to approximately 8.9 × 10 -4 MPa, plasma glow was started and oxygen plasma treatment was performed for 2 minutes to enhance surface activity; the thickness of the flexible substrate layer 1 in the central area was 0.1 mm, and the thickness in the edge area was 0.12 mm; S2: Take 3 mL of HEMA prepolymer solution and add it to the spray pen. Fix the sensor substrate in the center of the spray turntable. The turntable speed is 1000 r / min. Use a spray pressure of 0.08 MPa and a distance of 15 cm to spray evenly in one go. UV curing: After spraying, the PDMS surface was immediately irradiated with a UV lamp at an intensity of 258 mW / cm² for 60 seconds to induce polymerization of HEMA on the PDMS surface, forming a dense hydrogel layer. The HEMA prepolymer solution is prepared as follows: Weigh 0.2 g of 819 photoinitiator into a 100 mL light-shielded (tin foil-wrapped) reagent bottle. Then, add 4 g of EGDMA (crosslinker) and 15.8 g of HEMA (monomer) and mix thoroughly to obtain a mixture. Place the mixture in an ultrasonic constant temperature washer (99% power) for 30 minutes to ensure that the photoinitiator is fully dissolved and obtain a uniform HEMA prepolymer solution. S31: Fixing the sample including the flexible substrate layer 1 and the hydrogel layer 3 in a 3D printed connector, connected to a central rotation axis; S32: Start the platform and set the speed to 1000 r / min; S33: PEDOT:PSS purchased from Shenzhen Yilai Technology Co., Ltd. was used as the raw material for rotary spray coating. The spraying parameters were set as spraying pressure 0.08 MPa, spraying distance 15 cm, spraying time 5 s, and spraying times 3 times; S34: After heating and drying at a low temperature of 60° C. for 2 hours, a continuous and uniform conductive functional layer 2 is formed to obtain an eye electrophysiological signal acquisition sensor (HPCL).

[0079] The sensor prepared by the present invention was further subjected to the following performance tests: 1. In vitro performance characterization 1.1 Mechanical modulus test The PPCL prepared in Example 1, the PDCL prepared in Example 14, and the HPCL prepared in Example 15 were subjected to standardized mechanical modulus tests. The tensile tests were performed using an electronic universal tensile testing machine with a loading rate set at 10 mm / min. During the tensile process, the load was recorded. , displacement , and calculate the stress σ, strain ε and Young's modulus E according to the following formula: Where A is the cross-sectional area of ​​the specimen, is the initial length, is the stretch deformation. Figure 8 As shown, the stress-strain (σ-ε) curve is finally drawn, and the Young's modulus of the device is calculated as an evaluation index of its flexibility.

[0080] Flexible visual electrophysiological sensors must adhere stably to the corneal surface and maintain a high level of wearing comfort, so their mechanical modulus must match that of corneal tissue. Excessively high moduli can not only weaken the sensor's conformability but also increase the foreign body sensation, induce eye irritation, and even corneal damage, thereby limiting their widespread use in clinical and routine testing. Test results show that all three sensors have a modulus below 0.5 MPa, demonstrating excellent mechanical compliance and effectively avoiding the discomfort and irritation associated with rigid sensors.

[0081] 1.2 Sensor biointerface characteristics test The surface wettability of the PPCL prepared in Example 1, the PDCL prepared in Example 14, and the HPCL prepared in Example 15 was tested using a static water contact angle test method. The specific operation was as follows: 5 μL of deionized water was dripped onto the functional area of ​​the device using a 0-10 μL micropipette. The water droplet profile was recorded in real time using a high-resolution camera, and its contact angle with the material surface was measured. Each sensor was tested three times, and the average value was taken as the evaluation index to ensure the accuracy and reproducibility of the experimental data. For details, see Figure 9-11 shown.

[0082] The experimental results show that PPCL and HPCL exhibit obvious advantages over PDCL in terms of surface hydrophilicity, verifying the effectiveness of hydrophilic coatings in optimizing the interface performance of flexible sensors.

[0083] 1.3 Sensor micro-performance test See also Figure 12 As shown, the cross-sectional structure of the conductive functional layer in the PDCL prepared in Example 14 was observed by SEM. It can be seen that the interface between the PEDOT:PSS conductive functional layer and the flexible substrate layer below is clear, and there is no obvious gap, peeling or delamination between the layers. The excellent performance of the PEDOT:PSS coating in structural continuity, thickness control and interface adhesion is verified from a microscopic level.

[0084] 1.4 Anti-interference test To simulate the eyelid sliding or head micro-movement situations that may be encountered in actual ERG detection, the PPCL prepared in Example 1 was placed in a beaker filled with artificial tears and connected to the LCR electrode clamp via a wire. At 0, 20, 40, and 60 minutes during the test, tweezers were used to shake the wires at both ends of the device three times per second to perform an artificial mechanical interference test. The artificial mechanical interference test device is as follows: Figure 13 As shown, the impedance data before and after the interference are recorded simultaneously, and the change rate ΔR / R0 is calculated; see Figure 14 As shown in the figure, the sensor has excellent anti-interference ability and basically does not affect the normal collection of ERG signals.

[0085] Considering that flexible devices may experience various degrees of bending and deformation during transportation, operation, or wearing, a step-bending experiment was designed to evaluate the impact of device structure on conductive performance. In the test, the effective optical area of ​​the PPCL prepared in Example 1 was gradually shortened by 1mm from an initial length of 12.6mm to a minimum of 4mm ( Figure 15 ), and record the impedance changes under different bending states. Figure 16 The variation trend of sensor impedance with deformation degree during step bending is demonstrated, indicating that the device still has good structural stability and conductive reliability under conventional bending amplitude conditions.

[0086] In order to verify the durability of the device during repeated use or long-term dynamic loading, a cyclic bending test was carried out. Figure 17 The optical functional area was bent to 2mm (strain>84%) and bent repeatedly 100 times. The impedance changes were recorded at 0, 50, and 100 times, and the performance degradation trend was observed to determine its long-term anti-interference stability. Figure 18As shown, the sensor maintains excellent signal stability even after 50 bending cycles. It's worth noting that this type of flexible corneal sensor is a disposable medical device, and its actual use primarily involves transportation, wearing, and short-term measurements, not long-term repetitive mechanical operation. Therefore, a 50-bending margin is sufficient to cover the typical physical stresses of its lifecycle and meet the reliability requirements of real-world applications.

[0087] 2. Animal Experiments To systematically evaluate the signal acquisition capabilities of three electrophysiological sensors (PDCL, PPCL, and HPCL) and explore their biocompatibility and advantages over clinical sensors, animal experiments were conducted according to the following methods: Eight adult male New Zealand White rabbits, weighing 2.0–2.5 kg, were used as the experimental animal model. All rabbits were provided by a reputable laboratory animal supplier and were in good health, with no confounding factors such as ocular structural abnormalities and systemic diseases. Prior to the experiment, all animals underwent a seven-day acclimatization period to ensure a stable baseline physiological state.

[0088] Among them, 6 rabbits were used for electroretinogram-related experiments, including ERG signal recording of healthy rabbits (3 rabbits) and ERG signal recording of pathological model rabbits (3 rabbits); the other 2 rabbits were used for cornea-sensor biointerface characterization experiments.

[0089] The animal housing environment was set to a 12-hour light / 12-hour dark cycle to simulate a natural circadian rhythm. The temperature was maintained between 20–24°C, and the relative humidity was maintained between 45% and 65%. During the experiment, the animals had free access to food and water. They received standardized pelleted feed and treated clean tap water to maintain normal metabolic and behavioral states.

[0090] To minimize animal stress responses and fluctuations in experimental data, animal behavioral status was observed and recorded before and after the experimental operation; at the same time, standardized anesthesia, fixation, and handling procedures were ensured during the operation to improve experimental repeatability and data reliability.

[0091] 2.1 Healthy rabbit ERG signal acquisition method Experimental steps: (1) Dark adaptation processing Rabbits were placed in complete darkness for 30–60 minutes of dark adaptation to activate the rod photoreceptor pathway. In the experimental group using contact lens sensors, sensor insertion was performed under dim red light to minimize interference with bright light and avoid damage to the sensor surface. After sensor installation, an additional 5 minutes of dark adaptation were performed to ensure retinal stability.

[0092] (2) Anesthesia and mydriasis General anesthesia: Urethane solution was injected through the ear vein at a dose of 2 g / kg body weight to ensure that the animals remained pain-free and motionless throughout the experiment.

[0093] Local anesthesia of the eyes: 0.5% proparacaine hydrochloride was dripped into both eyes before the experiment to relieve the stress response of the corneal area to the sensor contact.

[0094] Mydriasis: Use 1% compound tropicamide eye drops and perform ERG test after the pupil is fully dilated to eliminate the effect of iris contraction on the amount of light entering.

[0095] (3)Sensor installation method Jet sensor: Gently place the sensor on the surface of the cornea, ensuring that its center is aligned with the pupil and maintains good conductive contact.

[0096] DTL conductive fiber sensor: Place the conductive fiber along the surface of the cornea and fix its ends at the inner and outer canthus to prevent sliding and displacement.

[0097] PDCL, PPCL, and HPCL flexible sensors: Place the sensor in the center of the cornea and adjust its posture to fully fit the corneal curvature.

[0098] Ground and reference electrodes: The ground electrode is placed on the skin surface of the tail, and the reference electrode is implanted in the temporal region through a double-ended needle electrode to ensure the stability of the overall circuit and minimize interference.

[0099] (4) Corneal lubrication and protection During the experiment, artificial tears were added regularly to lubricate the cornea, keep the surface moist, and reduce mechanical damage or corneal drying caused by sensor contact or prolonged exposure.

[0100] (5) Signal acquisition Under dark-adapted conditions: record ERG waveforms and OPS waveforms under flash stimulation of 0.01, 3.0, and 10.0 cd·s / m².

[0101] Under light-adapted conditions: ERG waveforms were recorded under background light adaptation at 3.0 cd·s / m² and 30 Hz flicker stimulation.

[0102] Each sensor collects 3 sets of data to ensure repeatability and stability.

[0103] (6) Data Analysis The signal amplitude, latency, and noise level recorded by each sensor were compared. Data from each group were statistically analyzed using one-way analysis of variance (ANOVA) to analyze the amplitude and implicit time of ERG signals. Differences in signal acquisition performance between different sensors were assessed, and a comprehensive assessment of their recording quality and practical application potential was made.

[0104] Figure 19 The standard ERG waveforms recorded by three electrophysiological sensors (PDCL, PPCL, and HPCL) in a healthy rabbit model are shown. (a) The stimulation intensity is 0.01 cd·s·m - Dark-adapted ERG of 2; (b) 3.0 cd·s·m -2 Dark-adapted ERG; (c) 3.0 cd·s·m -2 Dark-adapted oscillation potential (OPs); (d) 10.0 cd·s·m -2 Dark-adapted ERG; (e) 3.0 cd·s·m -2 (f) 30 Hz flash ERG, covering the main stimulus conditions of dark adaptation and light adaptation. Analysis results show that all three types of sensors can stably obtain ERG signals without interfering with natural eye movements. The waveform characteristics are clear, the a-wave and b-wave structures are intact, and the amplitude changes are consistent with physiological laws.

[0105] Figure 20 ERG signals were recorded using PPCL, Jet, and DTL in the same animal model (n ≥ 3); (a) the stimulation intensity was 0.01 cd·s·m -2 Dark-adapted ERG; (b) 3.0 cd·s·m -2 Dark-adapted ERG; (c) 3.0 cd·s·m -2 Dark-adapted oscillation potential (OPs); (d) 10.0 cd·s·m -2 Dark-adapted ERG; (e) 3.0 cd·s·m -2 Light-adapted ERG; (f) 30 Hz flash ERG; The waveform amplitude recorded by PPCL is slightly higher than that of Jet sensor and significantly better than DTL, reflecting better signal recording performance.

[0106] Figure 21 Further statistics Figure 20The mean amplitude (a) and latency (b) of ERGs under various test conditions were analyzed using one-way analysis of variance (ANOVA). While there was no statistically significant difference in amplitude between the PPCL and Jet sensors (p>0.05), the mean amplitude recorded by the PPCL was slightly higher than that of the Jet sensor, and the signal latency was shorter. This suggests that the PPCL can replace the clinically popular Jet sensor in terms of signal intensity. Furthermore, the mean amplitude recorded by the PPCL was significantly higher than that of the DTL sensor when tested with Dark 3.0, 10.0, Light 3.0, and 30 Hz light flicker (p<0.001), further demonstrating the superiority of the PPCL in signal quality.

[0107] 2.2 ERG signal acquisition method for pathological model rabbits Experimental steps: (1) Drug preparation Dissolve cefuroxime sodium powder in sterile saline to prepare a 1 mg / 0.1 mL injection. Mix thoroughly before use and store at low temperature.

[0108] (2) Animal pretreatment Refer to the healthy rabbit experimental process to complete dark adaptation, general and local anesthesia, and mydriasis.

[0109] (3) Intravitreal injection modeling Using a 28-gauge needle, puncture approximately 3 mm posterior to the corneal limbus and slowly inject 0.1 mL of cefuroxime solution into the center of the vitreous. The injection should be performed under aseptic conditions, and appropriate pressure should be applied to the injection site postoperatively to prevent reflux of the solution and fluctuations in intravitreal pressure.

[0110] (4) Sensor installation and corneal lubrication According to the healthy rabbit experimental process, various electrophysiological sensors and grounding and reference electrodes were installed, and artificial tears were added regularly during the entire signal acquisition process to ensure that the cornea was moist and in sufficient contact, thereby reducing damage or interference to the cornea caused by the operation.

[0111] (5) ERG signal acquisition Dark 3.0 ERG responses were recorded at 30 minutes and 24 hours after model establishment, capturing the primary waveforms of the a and b waves. At least three replicates of data were collected for each sensor to ensure statistical reliability.

[0112] (6) Postoperative observation and animal care Closely monitor the animal's eyes, paying particular attention to any complications such as inflammation, bleeding, and cloudiness. Ensure the animal's diet and activities are normal during the recovery period.

[0113] (7) Data processing and analysis The collected ERG waveform data were analyzed for amplitude, latency, and signal-to-noise ratio. The recording quality of different sensors under pathological conditions was compared. Statistical methods were used to evaluate the significance and regularity of signal changes, and the adaptability of flexible corneal electrophysiological sensors under conditions of abnormal retinal function was analyzed.

[0114] Figure 22 The following figure shows ERG waveforms recorded using PPCL and Jet sensors in a pathological model, with changes in a-wave and b-wave amplitudes annotated. This experiment used the Dark 3.0 standard protocol for ERG testing; (a) shows the ERG waveform before modeling; (b) shows the ERG waveform 30 minutes after modeling; and (c) shows the ERG waveform 24 hours after modeling. The dotted lines in the figure indicate the a-wave and b-wave amplitudes recorded by PPCL. The results show that PPCL still outperforms Jet sensors in signal recording capabilities under pathological conditions.

[0115] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. An eye electrophysiological signal acquisition sensor, characterized in that: The structure is an aspherical curved surface, comprising a flexible base layer (1) and a conductive functional layer (2) stacked in sequence from the outside to the inside; the conductive functional layer (2) is a continuous conductive film.

2. The ocular electrophysiological signal acquisition sensor according to claim 1, wherein: The curvature radius of the flexible base layer (1) is 7.16-7.17 mm.

3. The ocular electrophysiological signal acquisition sensor according to claim 2, wherein: The thickness of the central area of ​​the flexible base layer (1) is 0.1 mm.

4. The ocular electrophysiological signal acquisition sensor according to claim 2, wherein: The thickness of the edge region of the flexible base layer (1) is 0.12 mm.

5. The ocular electrophysiological signal acquisition sensor according to claim 1, wherein: The material of the flexible base layer (1) is polydimethylsiloxane.

6. The ocular electrophysiological signal acquisition sensor according to claim 1, wherein: The material of the conductive functional layer (2) is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate.

7. The ocular electrophysiological signal acquisition sensor according to any one of claims 1 to 6, characterized in that: It also includes a hydrogel layer (3) arranged between the flexible base layer (1) and the conductive functional layer (2).

8. The ocular electrophysiological signal acquisition sensor according to claim 7, wherein: The material of the hydrogel layer (3) is polyvinyl alcohol or hydroxyethyl methacrylate.

9. A method for preparing the ocular electrophysiological signal acquisition sensor according to any one of claims 1 to 8, characterized in that: The steps include: S1: After mixing PDMS with a curing agent, the mixture is placed in an aspheric surface mold for degassing and curing to obtain a flexible base layer (1); S2: using poly(3,4-ethylenedioxythiophene):polystyrene sulfonate) as a raw material, depositing a conductive layer on the surface of the flexible substrate layer (1) by spin spraying to obtain a conductive functional layer (2); The spraying parameters are set as spraying pressure 0.06-0.16 MPa, spraying distance 15 cm, spraying time 1-9 s, and spraying times 1-5 times.

10. The method for preparing the ocular electrophysiological signal acquisition sensor according to claim 9, wherein: Before step S2, the method further includes: preparing a hydrogel layer (3) on the surface of the flexible base layer (1).

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