Artificial-biological synaptic coupled photoelectric memristor for brain-computer interface, and preparation method and application of artificial-biological synaptic coupled photoelectric memristor

Abstract

The invention discloses an artificial-biological synapse coupled photoelectric memristor for a brain-computer interface and a preparation method and application of the artificial-biological synapse coupled photoelectric memristor, and belongs to the technical field of brain-computer interfaces. The artificial-biological synapse coupled photoelectric memristor for the brain-computer interface comprises an FTO substrate, and a ZnO thin film, a MnO2 thin film and an Ag electrode which are sequentially sputtered and deposited on the FTO substrate, and the FTO substrate and the Ag electrode are respectively used as a lower electrode and an upper electrode. The artificial-biological synapse coupled photoelectric memristor stably responds to light with the wavelength of 365 nm and light with the wavelength of 395 nm. The artificial-biological synapse coupled photoelectric memristor has a good application prospect in the field of electronic devices such as brain-computer interfaces, flexible electronic device integration and implantable electronic equipment. The method and the device are used for solving the technical problems of insufficient function compatibility and signal matching between an artificial synapse and a biological synapse based on a memristor.

Description

Technical Field

[0001] This invention belongs to the field of brain-computer interface technology, specifically relating to an opto-memristor for artificial-biological synaptic coupling in brain-computer interfaces, its preparation method, and its application. Background Technology

[0002] Neurological dysfunction caused by spinal cord injury, neurodegenerative diseases, and other conditions has become a major health challenge. These injuries often lead to the breakage or functional degeneration of synaptic connections between neurons, obstructing neural signal transmission pathways and resulting in irreversible consequences such as limb paralysis and cognitive impairment. Synapses, as the core structure for signal transmission in the nervous system, possess plasticity that forms the basis for learning, memory, and neural pathway remodeling. However, traditional circuit components are unable to match the plasticity of biological synapses, significantly limiting their applications in brain-computer interfaces, neural repair, and other fields.

[0003] Based on this, artificial synaptic devices that simulate the function of biological synapses have emerged. Among them, memristors, as a novel type of synaptic device with dynamic resistance regulation characteristics, are becoming a research focus in the field of brain-computer interfaces (BCIs) due to their high similarity to the structure of biological neural synapses. These devices provide hardware-level solutions for efficient neural signal processing and functional coupling with biological systems. For human-computer interaction, their low-power neuromorphic computing capabilities support high-fidelity processing of physiological signals (such as electroencephalography and electromyography), enabling rapid and adaptive responses to human intentions.

[0004] Nevertheless, current memristors still have limitations in brain-computer interface applications, mainly due to insufficient compatibility and signal matching between memristor-based artificial synaptic devices and biological synapses. Specifically, signal transmission in biological synapses relies on weak electrochemical coupling, with signal amplitudes typically ranging from microvolts to millivolts, and exhibiting highly dynamic spatiotemporal characteristics. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide an optoelectronic memristor for artificial-biological synaptic coupling in brain-computer interfaces, its preparation method and application, so as to solve the technical problems of insufficient functional compatibility and signal matching between memristor-based artificial synapses and biological synapses.

[0006] To achieve the above objectives, the present invention employs the following technical solution: One aspect of the present invention provides an opto-memristor for artificial-biological synaptic coupling in brain-computer interfaces, comprising an FTO substrate and ZnO thin film, MnO2 thin film and Ag electrode sequentially sputtered and deposited on the FTO substrate; with the FTO substrate and Ag electrode being the lower electrode and the upper electrode, respectively.

[0007] In one embodiment, the artificial-biological synaptic coupled photomemristor has a photostable response to wavelengths of 365 nm and 395 nm.

[0008] In one embodiment, the pulses transmitted through the photoelectric memristor for the artificial-biological synaptic coupling of the brain-computer interface exhibit LTP / LTD characteristics.

[0009] Another aspect of the present invention provides a method for fabricating an opto-memristor for artificial-biological synaptic coupling in a brain-computer interface, comprising the following steps: Clean the FTO substrate and use the FTO substrate as the lower electrode of the artificial-biological synaptic coupled photoelectric memristor; ZnO thin films were deposited on the FTO substrate by magnetron sputtering. A MnO2 thin film was deposited on the ZnO thin film by magnetron sputtering. An Ag electrode was fabricated on the MnO2 thin film using magnetron sputtering to obtain an opto-memristor for artificial-biological synaptic coupling in brain-computer interfaces.

[0010] In one embodiment, the process of cleaning the FTO substrate is as follows: The FTO substrate was sequentially immersed in deionized water, alcohol, acetone, alcohol, and deionized water and sonicated for 20-30 minutes.

[0011] In one embodiment, the sputtering deposition process of the ZnO thin film is as follows: A ZnO target was installed on the magnetron sputtering gun, with a target-to-substrate distance of 9-11 cm. The background vacuum in the sputtering chamber was then evacuated to 3 × 10⁻⁶. -4 ~4×10 -4 The sputtering pressure is 0.7~1.0 Pa, and the sputtering power is 60~80 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time is 40~60 min.

[0012] In one embodiment, the process of sputtering and depositing the MnO2 thin film is as follows: A MnO2 oxide target with an Mn to O atomic ratio of 1:2 was installed on the magnetron sputtering gun. The target-substrate distance was set to 9-11 cm, and the background vacuum of the sputtering chamber was evacuated to 3 × 10⁻⁶. -4 ~4×10 -4 The sputtering pressure is 0.6~0.8 Pa, and the sputtering power is 60~70 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time is 50-60 minutes.

[0013] In one embodiment, the specific process of preparing the upper Ag electrode on the MnO2 thin film is as follows: A perforated metal mask is placed on the surface of the MnO2 thin film. An Ag metal target is mounted on a DC magnetron sputtering target with a target-to-substrate distance of 9-11 cm. The background vacuum of the sputtering chamber is evacuated to 2 × 10⁻⁶. -4 ~3×10 -4 The sputtering pressure is 0.5~0.8 Pa, and the sputtering power is 60~80 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time is 10-12 minutes.

[0014] In one embodiment, the holes in the metal mask are circular holes, and the upper electrode Ag electrode is circular in shape.

[0015] In another aspect, the present invention provides an application of an artificial-biological synaptic coupling photoelectric memristor for brain-computer interfaces in brain-computer interface devices, flexible electronic integrated devices, and implantable electronic devices.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides an opto-memristor for artificial-biological synaptic coupling in brain-computer interfaces. This Ag / MnO2 / ZnO / FTO memristor device is sensitive to photoelectric information. One key aspect of this invention is the use of a ZnO thin film with photoelectric behavior as one layer in a composite functional layer. This allows the Ag / MnO2 / ZnO / FTO memristor device to exhibit photoelectric behavior, resulting in better signal matching between the device's current response and the biological synapse under a 365nm light pulse. Another key aspect is the use of MnO2 as one layer in the composite functional layer. Since MnO2 provides a source of oxygen vacancies, the photoelectric synaptic behavior of the device is more stable, resolving the functional compatibility issue between traditional memristor artificial synapses and biological synapses. Using FTO as a substrate to meet biocompatibility requirements, and utilizing ZnO and MnO2 thin films as intermediate layers to achieve photoelectric response, with Ag as the top electrode and FTO as the bottom electrode, a flexible memristor device sensitive to photoelectric pulses has been developed. This device uses ZnO and MnO2, which exhibit photoelectric behavior, as the functional layers of a memristor. It is connected to the memristor via implanted electrodes. Experiments have shown that when implanted in the brains of SD mice, the memristor effectively stimulates the mouse brain with a significant and reproducible effect. It shows great promise for applications in brain-computer interfaces, flexible electronic device integration, and implantable electronic devices. Attached Figure Description

[0017] Figure 1This is a stability analysis diagram of the maximum and minimum conductance values ​​of the memristor device prepared in Example 1 of the present invention under stimulation by 350 ±1 V electrical pulses; Figure 2 This is a graph showing the electromyographic changes in the forelimb of a mouse caused by stimulation after the memristor device prepared in Example 1 of this invention is connected to the brain of a C57BL / 6 mouse. Figure 3 This is an electromyography (EMG) diagram of the Ag / MnO2 / ZnO / FTO memristor device prepared in Example 1 under the first pulse of 1Hz low-frequency stimulation after changing the high-frequency stimulation. Figure 4 The image shows the electromyographic changes of C57BL / 6 mice under 365 nm light irradiation with and without the Ag / MnO2 / ZnO / FTO memristor device prepared in Example 1. Detailed Implementation

[0018] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0019] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0020] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0021] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0022] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0023] This invention provides an opto-memristor for artificial-biological synaptic coupling in brain-computer interfaces, its fabrication method, and its application.

[0024] This invention provides an opto-memristor for artificial-biological synaptic coupling in brain-computer interfaces. The opto-memristor for artificial-biological synaptic coupling in brain-computer interfaces is an Ag / MnO2 / ZnO / FTO memristor device. The Ag / MnO2 / ZnO / FTO memristor device includes an FTO substrate and ZnO thin film, MnO2 thin film and Ag electrode sequentially sputtered and deposited on the FTO substrate; the FTO substrate and the Ag electrode are the lower electrode and the upper electrode, respectively.

[0025] Among them, MnO2 film and ZnO film serve as composite functional layers. ZnO film imparts photoelectric synaptic behavior to the artificial-biological synaptic coupling photoelectric memristor, while MnO2 film provides a source of oxygen vacancies, making the photoelectric synaptic behavior of the device more stable.

[0026] The aforementioned ZnO thin film enables the artificial-biological synaptic coupled photomemristor to respond stably to light wavelengths of 365nm and 395nm, and the pulses transmitted through the artificial-biological synaptic coupled photomemristor for brain-computer interfaces exhibit LTP / LTD characteristics.

[0027] This invention also provides a method for fabricating a photoresponse memristor for artificial-biological synaptic coupling, comprising the following steps: Step 1: Clean the substrate. Place the FTO substrate in deionized water, alcohol, acetone, alcohol, and deionized water in sequence and sonicate for 20-30 minutes. After drying the FTO substrate with N2, place it in the magnetron sputtering chamber as the bottom electrode of the memristor. With the FTO thin film as a transparent conductive film and as the bottom electrode, FTO can form a good match with the work function of ZnO, so that the device has very stable memristor behavior.

[0028] Step 2: A ZnO thin film is deposited on the FTO substrate by magnetron sputtering. The ZnO thin film is a thin film with photoelectric behavior, and ZnO can achieve a stable response to light with wavelengths of 365nm and 395nm.

[0029] The specific process is as follows: A ZnO target is installed on the magnetron sputtering gun, the target-substrate distance is set to 9-11 cm, and the background vacuum of the sputtering chamber is evacuated to 3 × 10⁻⁶. -4 ~4×10 -4 The sputtering pressure is 0.7~1.0 Pa, and the sputtering power is 60~80 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time is 40~60 min.

[0030] Step 3: A MnO2 thin film is deposited on the ZnO thin film by magnetron sputtering. MnO2 is used as one of the composite functional layers. Since MnO2 can provide oxygen vacancy sources, the photoelectric synaptic behavior of the device is more stable.

[0031] The specific process is as follows: A MnO2 oxide target is installed on the magnetron sputtering gun, with an Mn to O atomic ratio of 1:2. The target-to-substrate distance is set to 9-11 cm, and the background vacuum of the sputtering chamber is evacuated to 3 × 10⁻⁶. -4 ~4×10 -4 The sputtering pressure is 0.6~0.8 Pa, and the sputtering power is 60~70 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time is 50-60 minutes.

[0032] Step 4: Prepare the top electrode Ag on the MnO2 thin film using magnetron sputtering. Cover the surface of the MnO2 thin film with a metal mask with holes, and deposit the top electrode Ag using DC sputtering.

[0033] The specific process is as follows: An Ag metal target is installed on a DC target for magnetron sputtering, with a target-to-substrate distance of 9-11 cm. The background vacuum in the sputtering chamber is then evacuated to 2 × 10⁻⁶. -4 ~3×10 -4 The sputtering pressure is 0.5~0.8 Pa, and the sputtering power is 60~80 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time is 10-12 minutes. Among them, 2×10 -4 ~3×10 -4 A high back vacuum (Pa) ensures a purer Ag electrode and prevents reaction between Ag and O. A sputtering power of 60-80 W ensures good Ag adhesion without penetrating the ZnO and MnO2 layers.

[0034] The metal mask has circular holes, and the upper electrode Ag is circular. Using Ag as the upper electrode makes it easier to form Ag-based conductive filaments in the functional layer.

[0035] A method of using a photoelectric memristor for artificial-biological synaptic coupling includes the following steps: Step 1: Implant metal electrodes (for photoelectric memristors used for artificial-biological synaptic coupling) into the brain nuclei of C57BL / 6 mice.

[0036] Step 2: Apply photoelectric pulse signals to the memristor, and the output pulses of the memristor stimulate the brain nuclei of C57BL / 6 mice.

[0037] Step 3: Record the electromyography of the forelimbs of C57BL / 6 mice using an electromyography device.

[0038] See Figures 1-4 The pulses transmitted through the photomemristor exhibit LTP / LTD characteristics. The stimulation output from the photomemristor effectively stimulates the brain nuclei of C57BL / 6 mice. When the stimulation exceeds the threshold, the limbs of the C57BL / 6 mice move. As can be seen from the above, by stimulating the animal's brain regions, the LTP behavior of the device is reflected in the electromyography of the animal's limbs.

[0039] The photoelectric memristor for artificial-biological synaptic coupling in brain-computer interfaces provided by this invention can be applied not only in brain-computer interface devices, but also in flexible electronic integrated devices and implantable electronic devices.

[0040] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0041] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0042] Example 1 This embodiment provides a method for fabricating an opto-memristor for artificial-biological synaptic coupling in brain-computer interfaces, comprising the following steps: Step 1: Clean the substrate. Place the FTO substrate in deionized water, alcohol, acetone, alcohol, and deionized water in sequence and sonicate for 20-30 minutes. After drying the FTO substrate with N2, place it in the magnetron sputtering chamber as the lower electrode of the memristor.

[0043] Step 2: Deposit ZnO thin film on FTO substrate by magnetron sputtering: Install ZnO target on magnetron sputtering gun, set target-substrate distance to 9-11 cm, and evacuate the sputtering chamber to 3 × 10⁻⁶. -4 The sputtering pressure was 0.7 Pa, and the sputtering power was 60 W / cm². Argon gas with a purity of 99.999% was introduced as the working gas. 2 The sputtering time was 60 min. These parameters ensure optimal ZnO deposition uniformity, yielding a ZnO film of approximately 150 nm.

[0044] Step 3: Deposit a MnO2 thin film on the deposited ZnO thin film using magnetron sputtering: Install an MnO2 oxide target on the magnetron sputtering gun, with an Mn:O atomic ratio of 1:2, set the target-substrate distance to 9-11 cm, and evacuate the sputtering chamber to a background vacuum of 3 × 10⁻⁶. -4 The sputtering pressure was 0.8 Pa, and the sputtering power was 60 W / cm². Argon gas with a purity of 99.999% was introduced as the working gas. 2 The sputtering time is 50 min.

[0045] Step 4: Using magnetron sputtering, prepare the top electrode Ag on the MnO2 deposited in the previous step to obtain a photoelectric memristor for artificial-biological synaptic coupling: Install the Ag metal target on the DC target of magnetron sputtering, set the target-substrate distance to 9-11 cm, and evacuate the sputtering chamber to a background vacuum of 2 × 10⁻⁶. -4 The sputtering pressure is 0.5 Pa, and the sputtering power is 60 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time was 10 minutes. Using Ag in this step greatly promotes the formation of Ag conductive filaments, thereby significantly improving the on / off ratio of the memristor. Furthermore, Ag can enhance the photoelectric response of the device.

[0046] Example 2 This embodiment provides a method for fabricating an opto-memristor for artificial-biological synaptic coupling in brain-computer interfaces, comprising the following steps: Step 1: Clean the substrate. Place the FTO substrate in deionized water, alcohol, acetone, alcohol, and deionized water in sequence and sonicate for 20-30 minutes. After drying the FTO substrate with N2, place it in the magnetron sputtering chamber as the lower electrode of the memristor.

[0047] Step 2: Deposit ZnO thin film on FTO substrate by magnetron sputtering: Install ZnO target on magnetron sputtering gun, set target-substrate distance to 9-11 cm, and evacuate the sputtering chamber to a base vacuum of 4 × 10⁻⁶ cm. -4 The sputtering pressure is 1.0 Pa, and the sputtering power is 80 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time was 60 minutes.

[0048] Step 3: Deposit a MnO2 thin film on the deposited ZnO thin film using magnetron sputtering: Install an MnO2 oxide target on the magnetron sputtering gun, with an Mn:O atomic ratio of 1:2, set the target-substrate distance to 9-11 cm, and evacuate the sputtering chamber to a background vacuum of 4 × 10⁻⁶. -4 The sputtering pressure was 0.6 Pa, and the sputtering power was 70 W / cm². Argon gas with a purity of 99.999% was introduced as the working gas.2 The sputtering time was 60 minutes.

[0049] Step 4: Using magnetron sputtering, prepare the top electrode Ag on the MnO2 deposited in the previous step to obtain a photoelectric memristor for artificial-biological synaptic coupling: Install the Ag metal target on the DC target of magnetron sputtering, set the target-substrate distance to 9-11 cm, and evacuate the sputtering chamber to a background vacuum of 3 × 10⁻⁶. -4 The sputtering pressure is 0.8 Pa, and the sputtering power is 80 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time was 12 minutes.

[0050] The photoelectric memristor for artificial-biological synaptic coupling prepared in Example 1 above was used for testing. The specific process is as follows: Step 1: Implant metal electrodes (for photoelectric memristors used for artificial-biological synaptic coupling) into the brain nuclei of C57BL / 6 mice.

[0051] Step 2: Apply photoelectric pulse signals to the memristor, and the output pulses of the memristor stimulate the brain nuclei of C57BL / 6 mice.

[0052] Step 3: Record the electromyography of the forelimbs of C57BL / 6 mice using an electromyography device.

[0053] Figure 1 This paper presents a stability analysis of the maximum and minimum conductance values ​​of the memristor device prepared in Example 1 of this invention under 350 ± 1 V electrical pulses. By selecting the maximum and minimum conductance values ​​of the device under 10 voltage pulse modulations, the results show that the device conductance did not exhibit drift under 350 voltage pulses, demonstrating good stability and conductance modulation capability.

[0054] Figure 2 This describes the electromyographic changes in the forelimbs of mice induced by stimulation of the memristor device prepared in Example 1 of this invention after being connected to the brain of C57BL / 6 mice. Under 1Hz frequency stimulation, the device exhibited good LTP / LTD behavior; after five 1Hz constant electrical pulse stimulations, the peak current of the mouse electromyographic signal gradually increased, exhibiting typical LTP. This LTP effect is not solely due to the synaptic device, but rather a result of the superposition of the synaptic device and the biological synapse.

[0055] Figure 3This describes the electromyographic (EMG) changes of the Ag / MnO2 / ZnO / FTO memristor device prepared in Example 1 under the first pulse of low-frequency stimulation at 1 Hz after a change in high-frequency stimulation. Here, a high-frequency component is introduced after the low-frequency component. By changing the high-frequency component, such as the high-frequency frequency, while keeping the low-frequency stimulation conditions fixed, the focus is on analyzing the modulation effect of high-frequency frequency changes on the low-frequency component and the resulting changes in limb responses. It can be seen that when high-frequency stimulation below 20 Hz cannot induce LTP behavior in the low-frequency component, when the high-frequency frequency is higher than 20 Hz, the EMG signal exhibits a greater burst of intensity under low-frequency stimulation as the high-frequency frequency increases.

[0056] Figure 4 This image shows the electromyographic (EMG) changes in C57BL / 6 mice under 365nm illumination with and without the Ag / MnO2 / ZnO / FTO memristor device prepared in Example 1. Electrical pulses below 1.4 V failed to trigger limb responses in either illuminated or dark backgrounds. Under a single 1.4 V pure electrical pulse, stimulation was insufficient to generate an EMG signal, while the 365 nm light background increased the stimulation intensity, causing the stimulus to exceed the animal's response threshold and trigger an action potential. This indicates that photoelectric synergistic stimulation improves the efficiency of synaptic regulation in animals, further expanding the application potential of synaptic devices in vivo.

[0057] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. An optoelectronic memristor for artificial-biological synapse coupling of brain-computer interface, characterized in that, The FTO substrate and the Ag electrode are respectively used as the lower electrode and the upper electrode.

2. The optoelectronic memristive artificial-biological synapse coupling for brain-computer interface of claim 1, wherein, The artificial-biological synapse coupled optoelectronic memristor is stable to light with wavelengths of 365 nm and 395 nm.

3. The optoelectronic memristive artificial-biological synapse coupling for brain-computer interface of claim 1, wherein, The pulse of the artificial-biological synapse coupled optoelectronic memristor for brain-computer interface has LTP / LTD characteristics.

4. A method for fabricating optoelectronic memristor for artificial-biological synapse coupling of brain-computer interface according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: cleaning the FTO substrate, taking the FTO substrate as the lower electrode of the artificial-biological synapse coupled optoelectronic memristor; sputtering and depositing a ZnO film on the FTO substrate by a magnetron sputtering method; sputtering and depositing a MnO2 film on the ZnO film by a magnetron sputtering method; preparing an upper electrode Ag electrode on the MnO2 film by a magnetron sputtering method to obtain the artificial-biological synapse coupled optoelectronic memristor for brain-computer interface.

5. The method of claim 4, wherein the optoelectronic memristor is a brain-machine interface artificial-biological synapse coupling device. The process of cleaning the FTO substrate is as follows: placing the FTO substrate into deionized water, alcohol, acetone, alcohol and deionized water in sequence and performing ultrasonic cleaning for 20-30 min.

6. The method of claim 4, wherein the optoelectronic memristor is a brain-machine interface artificial-biological synapse coupling device. The process of sputtering and depositing the ZnO film is as follows: The ZnO target material was installed on a magnetron sputtering target gun, the target-substrate distance was set to 9-11 cm, the sputtering chamber base vacuum was pumped to 3×10 -4 ~4×10 -4 Pa, argon gas with a purity of 99.999% was introduced as a working gas, the sputtering pressure was 0.7-1.0 Pa, the sputtering power was 60-80 W / cm 2 , and the sputtering time was 40-60 min.

7. The method of claim 4, wherein the optoelectronic memristor is a brain-machine interface artificial-biological synapse coupling device. The process of sputtering and depositing the MnO2 film is as follows: A MnO2 oxide target with an Mn to O atomic ratio of 1:2 was installed on the magnetron sputtering gun. The target-substrate distance was set to 9-11 cm, and the background vacuum of the sputtering chamber was evacuated to 3 × 10⁻⁶. -4 ~4×10 -4 The sputtering pressure is 0.6~0.8 Pa, and the sputtering power is 60~70 W / cm². Argon gas with a purity of 99.999% is introduced as the working gas. 2 The sputtering time is 50-60 minutes.

8. The method of claim 4, wherein the optoelectronic memristor is an artificial- biological synapse for brain-computer interface. The specific process of preparing the upper electrode Ag electrode on the MnO2 film is as follows: A metal mask with holes is covered on the surface of the MnO2 film, an Ag metal target is installed on a magnetron sputtering direct current target, a target-substrate distance is set to 9-11 cm, a sputtering chamber base vacuum is pumped to 2×10 -4 ~3×10 -4 Pa, argon gas with a purity of 99.999% is introduced as a working gas, a sputtering gas pressure is 0.5-0.8 Pa, a sputtering power is 60-80 W / cm 2 , and a sputtering time is 10-12 min.

9. The method of claim 4, wherein the optoelectronic memristor is an artificial- biological synapse for brain-computer interface. The hole of the metal mask is a circular hole, and the shape of the upper electrode Ag electrode is circular.

10. Application of the artificial-biological synapse coupled optoelectronic memristor for brain-computer interface according to any one of claims 1 to 3 in a brain-computer interface device, a flexible electronic integrated device and an implantable electronic device.

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