Method for manufacturing an electrooculogram sensor and electrooculogram sensor

Abstract

The application discloses a method for preparing an electrooculogram signal sensor and the electrooculogram signal sensor. The method comprises the following steps: providing a flexible substrate precursor solution, wherein the flexible substrate precursor solution comprises a polymer and an organic solvent; spinning the flexible substrate precursor solution through an electrostatic spinning process to obtain a flexible substrate with a thickness of 50 nm-10 microns; and arranging a lead electrode with a thickness of 100 nm-500 nm on the surface of the flexible substrate to obtain the electrooculogram signal sensor. The method has the advantages of simple manufacturing process, high cost-effectiveness and the design target of non-inductive wearing of the electrooculogram signal sensor.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biosensors, and particularly relates to a method for preparing an electrooculogram sensor and an electrooculogram sensor. BACKGROUND

[0002] With the increasing number of motor vehicles, the rate of traffic accidents caused by fatigue driving is also rising year by year, accounting for more than 20% of the total number of traffic accidents and more than 40% of the proportion of major traffic accidents. Among the traffic accidents caused by fatigue driving, nearly 90% of the accidents are caused by the driver's failure to react in time when he enters a fatigue state. Studies have shown that by analyzing the eye movement patterns of the driver, such as the frequency of eye closure, the time of instantaneous closure, the movement of the eyes and the pupil response, etc., the fatigue level of the driver can be effectively evaluated. Therefore, there is a need for a device that is easy to wear and can monitor in real time whether the driver is fatigued. The human eye can provide physiological information of the body to the outside world, so the fatigue state can be quickly detected through eye movement and blinking. The electrooculogram (EOG) sensor is being used more and more in fatigue monitoring systems due to its non-invasive, easy-to-wear and real-time monitoring characteristics.

[0003] The electrooculogram signal is derived from the potential difference between the retina and the cornea, and is a convenient and fast method for measuring eye movement, which can reflect the reading state, sleep pattern, brain condition, drowsiness and eye fatigue, etc. and can be used in scenarios such as fatigue warning, human-computer interaction and disease diagnosis (such as diagnosis of hyperactivity disorder, stroke, autism, Alzheimer's disease and Parkinson's disease).

[0004] Traditional electrooculogram (EOG) sensors usually use metal electrodes to collect EOG signals, such as silver / silver chloride (Ag / AgCl) gel electrodes. Although the manufacturing method is simple and the cost is low, most of the commercially available dry or wet Ag / AgCl electrodes used in practical applications are too thick, heavy, rigid and uncomfortable to attach to the delicate skin around the eyes, and are very obvious on the face, affecting the overall appearance. In addition, for wet electrodes, the face needs to be treated with oil and keratin before wearing, the gel will irritate the skin, and the wet electrode will dry out over time, resulting in a decrease in the quality of the recorded signal. Dry electrodes have high electrode-skin contact impedance due to their non-conformal contact with the skin, and are easily affected by motion artifacts. For example, Searle A and Kirkup L designed an ultra-thin and stretchable tattoo-like EOG sensor based on a polymer substrate and a thin serpentine gold tape, which is very noticeable when applied to prominent areas such as the face. In other studies, EOG sensors combined with other sensors and circuit elements are integrated into a patch with a thickness of a few millimeters, which is not only obvious, but also hard, which will interfere with facial expressions. Therefore, there is an urgent need to develop flexible skin sensors for unobtrusive electrooculography. SUMMARY

[0005] To solve the above problems, the application provides a method for preparing an electrooculogram signal sensor and an electrooculogram signal sensor. The method applies a traditional electrospinning process to the manufacture of flexible microelectronic devices, has a simple manufacturing process, is cost-effective, and can achieve the design goal of unobtrusive wearing of the electrooculogram signal sensor.

[0006] The first aspect of the application provides a method for preparing an electrooculogram signal sensor, comprising:

[0007] providing a flexible substrate precursor solution, the flexible substrate precursor solution comprising a polymer and an organic solvent;

[0008] spinning the flexible substrate precursor solution by an electrospinning process to obtain a flexible substrate with a thickness of 50 nm to 10 μm;

[0009] providing a lead electrode with a thickness of 100 nm to 500 nm on the surface of the flexible substrate to obtain an electrooculogram signal sensor.

[0010] The method of the present application weaves the flexible substrate precursor solution through an electrostatic spinning process to obtain a flexible substrate with a thickness of 50 nm to 10 pm. The manufacturing process of the substrate is simple and has high cost efficiency. The electrooculogram signal sensor prepared according to the method of the present application is composed of a nanometer or micrometer flexible substrate and a nanometer lead electrode. The light and thin design improves the air permeability of the device and reduces the Young's modulus of the device. Therefore, the electrooculogram signal sensor prepared according to the method of the present application can have a wider application environment. In the use process, the electrooculogram signal sensor can always conform to the skin attachment, so as to achieve the design goal of non-inductive wearing and has good service performance.

[0011] In any embodiment of the present application, a flexible substrate precursor solution is provided, comprising:

[0012] The polymer is dissolved in an organic solvent to obtain a flexible substrate precursor solution with a mass concentration of 5% to 30%.

[0013] In any embodiment of the present application, the polymer comprises one or more of polyurethane, polyethylene terephthalate, and polyimide.

[0014] The organic solvent comprises one or more of N,N-dimethylacetamide, N,N-dimethylformamide, and trichloromethane.

[0015] In any embodiment of the present application, the flexible substrate comprises polymer fibers with a diameter of 50 nm to 10 pm.

[0016] In any embodiment of the present application, a lead electrode with a thickness of 100 nm to 500 nm is arranged on the surface of the flexible substrate, comprising:

[0017] The metal film is deposited on the surface of the flexible substrate according to a predetermined electrode layout to form a lead electrode with a thickness of 100 nm to 500 nm.

[0018] In any embodiment of the present application, after arranging the lead electrode on the surface of the flexible substrate, the method further comprises:

[0019] The adhesive layer with a hollow part is arranged on the side of the flexible substrate facing the lead electrode, wherein the hollow part exposes a part of the lead electrode.

[0020] In any embodiment of the present application, the adhesive layer comprises a polymer substrate and a pressure-sensitive layer on the surface of the polymer substrate.

[0021] In any embodiment of the present application, the flexible substrate comprises a first flexible substrate;

[0022] The method comprises: arranging a first lead electrode and a second lead electrode on a first flexible substrate surface;

[0023] The first lead electrode comprises a first external electrode, a first connecting electrode and a first active electrode, the first external electrode is rectangular, triangular, rhombic or circular, and the first external electrode is used for connecting with a signal acquisition device; the first active electrode is rectangular, triangular, rhombic or circular, and the first active electrode is used for collecting an electrooculogram signal; and the first connecting electrode is rectangular, and the first connecting electrode is used for connecting the first external electrode and the first active electrode.

[0024] The second lead electrode comprises a second external electrode, a second connecting electrode and a second active electrode, the second external electrode is rectangular, triangular, rhombic or circular, and the second external electrode is used for connecting with the signal acquisition device; the second active electrode is rectangular, triangular, rhombic or circular, and the second active electrode is used for collecting the electrooculogram signal; and the second connecting electrode is rectangular, and the second connecting electrode is used for connecting the second external electrode and the second active electrode.

[0025] The first external electrode and the second external electrode are opposite to each other along a first direction, and the first active electrode and the second active electrode are opposite to each other along the first direction; in the first direction, a distance between the first external electrode and the second external electrode is smaller than a distance between the first active electrode and the second active electrode.

[0026] In any embodiment of the present application, the flexible substrate further comprises a second flexible substrate; and the method further comprises: arranging a third lead electrode on a surface of the first flexible substrate; and arranging a fourth lead electrode on a surface of the second flexible substrate.

[0027] The third lead electrode comprises a third external electrode, a third connecting electrode and a third active electrode, the third external electrode is rectangular, triangular, rhombic or circular, and the third external electrode is used for connecting with the signal acquisition device; the third active electrode is rectangular, triangular, rhombic or circular, and the third active electrode is used for collecting the electrooculogram signal; and the third connecting electrode is rectangular, and the third connecting electrode is used for connecting the third external electrode and the third active electrode.

[0028] The fourth lead electrode comprises a fourth external electrode, a fourth connecting electrode and a fourth active electrode, the fourth external electrode is rectangular, triangular, rhombic or circular, and the fourth external electrode is used for connecting with the signal acquisition device; the fourth active electrode is rectangular, triangular, rhombic or circular, and the fourth active electrode is used for collecting the electrooculogram signal; and the fourth connecting electrode is rectangular, and the fourth connecting electrode is used for connecting the fourth external electrode and the fourth active electrode.

[0029] The fourth lead electrode is arranged opposite to the third lead electrode along a second direction, and the second direction is perpendicular to the first direction.

[0030] The second aspect of the present application provides an electro-oculogram sensor prepared by the method according to any one of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a structural schematic diagram of a first lead component in an electro-oculogram sensor according to an embodiment of the present application;

[0032] Figure 2 is a structural schematic diagram of a second lead component in an electro-oculogram sensor according to another embodiment of the present application;

[0033] Figure 3 is a structural schematic diagram of an electro-oculogram sensor according to yet another embodiment of the present application;

[0034] Figure 4 is an electrode layout of an electro-oculogram sensor according to still another embodiment of the present application;

[0035] Figure 5 is an optical microscope image of an edge position of a first flexible substrate in an electro-oculogram sensor according to still another embodiment of the present application;

[0036] Figure 6 is an optical microscope image of a center position of a first flexible substrate in an electro-oculogram sensor according to still another embodiment of the present application;

[0037] Figure 7 is a metallographic microscope image of a first flexible substrate in an electro-oculogram sensor under 5X magnification according to still another embodiment of the present application;

[0038] Figure 8 is a metallographic microscope image of a first flexible substrate in an electro-oculogram sensor under 10X magnification according to still another embodiment of the present application;

[0039] Figure 9 is a metallographic microscope image of a first flexible substrate in an electro-oculogram sensor under 20X magnification according to still another embodiment of the present application;

[0040] Figure 10 is a metallographic microscope image of a first flexible substrate in an electro-oculogram sensor under 50X magnification according to still another embodiment of the present application;

[0041] Figure 11 is a scanning electron microscope image of a first flexible substrate in an electro-oculogram sensor according to still another embodiment of the present application;

[0042] Figure 12 is an attachment position schematic diagram of an electro-oculogram sensor according to still another embodiment of the present application;

[0043] Figure 13 is a schematic diagram of an electrooculogram sensor test platform provided by another embodiment of the present application;

[0044] Figure 14 is a test result diagram of an electrooculogram signal of vertical eye movement detected by an electrooculogram signal sensor provided by another embodiment of the present application;

[0045] Figure 15 is a test result diagram of an electrooculogram signal of horizontal eye movement detected by an electrooculogram signal sensor provided by another embodiment of the present application;

[0046] Figure 16 is a test result diagram of an electrooculogram signal of diagonal eye movement detected by an electrooculogram signal sensor provided by another embodiment of the present application;

[0047] Figure 17 is a scatter plot of eye movement slope characteristics detected by an electrooculogram signal sensor provided by another embodiment of the present application;

[0048] Figure 18 is a test result diagram of a blink signal detected by an electrooculogram signal sensor provided by another embodiment of the present application;

[0049] Figure 19 is a time domain diagram of a single blink signal in different blink states detected by an electrooculogram signal sensor provided by another embodiment of the present application.

[0050] In the drawings, the drawings are not necessarily drawn according to the actual proportions. DETAILED DESCRIPTION

[0051] In order to make the application purposes, technical solutions and beneficial technical effects of the present application clearer, the present application will be further described in detail below in combination with embodiments. It should be understood that the embodiments described in the present specification are only for the purpose of explaining the present application, and are not intended to limit the present application.

[0052] For the sake of simplicity, only some numerical ranges are explicitly disclosed in the present application. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, likewise any upper limit can be combined with any other upper limit to form a range not explicitly recited. In addition, although not explicitly recited, every point or single numerical value between the range endpoints is included in the range. Thus, every point or single numerical value can be combined as its own lower limit or upper limit with any other point or single numerical value or with other lower limits or upper limits to form a range not explicitly recited.

[0053] In the description of the present application, it should be noted that, unless otherwise specified, "above", "below" are inclusive of the number, and the meaning of "multiple" in "one or more" is two and more than two.

[0054] The above application content of the present application is not intended to describe each disclosed embodiment or each implementation in the present application. The following description illustrates exemplary embodiments more specifically. In many places throughout the application, guidance is provided by a series of examples, which can be used in various combinations. In each instance, the enumeration is only representative of a group and should not be interpreted as exhaustive.

[0055] As described in the background, under the current technological development, it is urgent to develop a flexible skin sensor for non-invasive electrooculogram measurement.

[0056] The related art relates to a skin-attached sensor based on single-crystal III-N thin film for eye movement monitoring, which converts various blink frequencies and skin deformations caused by eye movements into electrical signal outputs. However, this sensor requires polydimethylsiloxane (PDMS) packaging, which results in excessive thickness and poor adhesion of the sensor.

[0057] The related art also relates to collecting EOG signals through graphene electronic tattoos (GET) for human-computer interaction to control the flight of a quadcopter. The GET sensor with a thickness of 350 nm exhibits 85% optical transparency and 50% stretchability in the visible light region. However, the preparation process of GET requires complex process steps (up to 27 steps), and the performance stability of GET prepared by single-layer graphene is difficult to control. Therefore, the production cost of GET sensor based on chemical vapor deposition growth is high. In addition, the interconnection and protection of ultra-thin bare GET still face major challenges.

[0058] In summary, although many research teams have studied flexible skin electrooculogram sensors, they have not yet reached the clinical medical stage. Many studies use multi-layer stacked deposited metal electrodes and encapsulated electrooculogram sensors with polymeric materials, but there are still several problems: complex preparation process, poor stability, and inability to wear for a long time due to material and volume thickness. The electrodes (such as metal sheet electrodes, gel patch electrodes) and lead wires used in the measurement of electrooculogram in laboratories or hospitals are too thick and hard, resulting in low comfort and difficulty in long-term wear. The research on skin film electronic devices for long-term non-invasive measurement of electrooculogram is still scarce.

[0059] In view of this, the inventors, through in-depth research and a large number of experiments, provide a method for preparing an electrooculogram signal sensor and an electrooculogram signal sensor.

[0060] The first aspect of the present application provides a method for preparing an electrooculogram signal sensor, comprising the following steps S10-S30.

[0061] S10, providing a flexible substrate precursor solution, the flexible substrate precursor solution comprising a polymer and an organic solvent.

[0062] In step S10, the polymer can include any polymer known in the art that can be used for a flexible substrate, as long as the polymer solution is suitable for the electrospinning process and the prepared substrate meets the requirements of air permeability, biocompatibility and stretchability, which are not limited herein. The organic solvent can include any organic solvent that can be used to dissolve the above-mentioned polymer, and the person skilled in the art can select a suitable organic solvent according to the type of polymer, which is not limited herein.

[0063] S20, spinning the flexible substrate precursor solution by an electrospinning process to obtain a flexible substrate with a thickness of 50 nm-10 μm.

[0064] In step S20, by adjusting the parameters of the electrospinning process, the concentration of the flexible substrate precursor solution and other parameters, the polymer fibers with a suitable diameter can be obtained, and then the flexible substrate with a thickness within the above range can be spun. For example, in the electrospinning process, the injection speed of the solution in the syringe can be 0.1-0.3 mm / min; the translation speed of the syringe can be 50-350 mm / min; the speed of the fiber receiving metal cylinder can be 40-80 mm / min; the distance between the syringe and the fiber receiving metal cylinder can be 15-30 cm; the spinning voltage can be positive 5-20 kV and negative -5-0 kV. The spinning time can be adjusted as needed, which can be about 1 h, for example.

[0065] S30, disposing a lead electrode with a thickness of 100 nm-500 nm on the surface of the flexible substrate to obtain an electrooculogram signal sensor.

[0066] The method of the present application spins the flexible substrate precursor solution by an electrospinning process to obtain a flexible substrate with a thickness of 50 nm-10 μm, which has a simple manufacturing process and high cost-effectiveness. The electrooculogram signal sensor prepared according to the method of the present application is composed of a nanoscale or micrometer flexible substrate and a nanoscale lead electrode, and its light and thin design not only improves the air permeability of the device, but also reduces the Young's modulus of the device. Therefore, the electrooculogram signal sensor prepared according to the method of the present application can have a wider range of application environments, and in the use process, the electrooculogram signal sensor can always conform to the skin and be attached, so as to achieve the design goal of non-inductive wearing and have good service performance.

[0067] In some embodiments, the flexible substrate precursor solution is provided, which can specifically include:

[0068] The polymer is dissolved in an organic solvent to obtain a flexible substrate precursor solution with a mass concentration of 5-30%.

[0069] Preferably, in some embodiments, the mass concentration of the polymer can also be 6-18%.

[0070] Without being bound to any theory or explanation, when the mass concentration of the polymer in the flexible substrate precursor solution is within the above suitable range, it is conducive to obtaining polymer fibers with a diameter of 50 nm-10 μm in combination with the electrospinning process. Thus, it is conducive to spinning a flexible substrate of single-layer fibers, thereby further meeting the air permeability requirement. In this way, it is conducive to realizing long-term and non-invasive wearing of the electrooculogram signal sensor.

[0071] In some embodiments, the polymer can include one or more of polyurethane (PU), polyethylene terephthalate (PET), and polyimide (PI).

[0072] The organic solvent can include one or more of N,N-dimethylacetamide (DMF), N,N-dimethylformamide (DMAc), and trichloromethane (TCM).

[0073] In some embodiments, the flexible substrate can include polymer fibers with a diameter of 50 nm-10 μm.

[0074] In the present application, the diameter of the polymer fibers can represent the diameter range of the polymer fibers in the flexible substrate, which can be determined by methods and instruments known in the art. For example, the SEM image of the flexible substrate can be taken by a scanning electron microscope (SEM), a number of (e.g., 3, 5, 10, etc.) test areas are randomly selected, the diameters of the fibers in the field of view are determined, and the diameter range of the fibers in all test areas is taken as the diameter range of the polymer fibers in the flexible substrate.

[0075] In some embodiments, a lead electrode with a thickness of 100 nm-500 nm is arranged on the surface of the flexible substrate, which can specifically include:

[0076] The metal film is deposited on the surface of the flexible substrate according to a predetermined electrode layout to form a lead electrode with a thickness of 100 nm-500 nm.

[0077] The above deposition can be realized by vacuum sputtering, magnetron sputtering, physical vapor deposition, electroless plating, etc. The above metal film can include metals such as platinum (Pt), gold (Au), and copper (Cu).

[0078] According to the above embodiment, the metal film is deposited on the surface of the flexible substrate according to the preset electrode layout. In this way, the process flow of the electrooculogram signal sensor can be further simplified, the production cost of the electrooculogram signal sensor can be reduced, and the performance stability of the electrooculogram signal sensor can be improved.

[0079] In some embodiments, after the lead electrodes are arranged on the surface of the flexible substrate, the method can further include:

[0080] The adhesive layer with the hollow part is arranged on the side of the flexible substrate facing the lead electrodes, wherein the hollow part exposes a part of the lead electrodes.

[0081] It can be understood that the lead electrodes can include external electrodes for connecting with the signal acquisition device and active electrodes for acquiring the electrooculogram signals. The hollow part can at least expose the external electrodes and the active electrodes, so that the external electrodes and the active electrodes can be in contact with the skin.

[0082] According to the above embodiment, the adhesive layer with the hollow part is arranged on the side of the flexible substrate facing the lead electrodes, so that the electrooculogram signal sensor can be firmly attached to the human skin via the adhesion of the adhesive layer. In this way, the electrooculogram signal sensor can meet the requirement of long-term wearing.

[0083] In some embodiments, the adhesive layer can include a polymer substrate and a pressure-sensitive layer on the surface of the polymer substrate.

[0084] The polymer substrate can include a fiber membrane prepared by an electrospinning process, for example, the material and structure of the polymer substrate can be the same as the flexible substrate. In one example, the thickness of the polymer substrate can be 50 nm to 10 μm.

[0085] The pressure-sensitive layer can include a pressure-sensitive adhesive material, for example, can include one or more of polydimethylsiloxane (PDMS), acrylate pressure-sensitive adhesive, hydrocolloid medical pressure-sensitive adhesive, etc.

[0086] Exemplarily, the adhesive layer with the hollow part is arranged on the side of the flexible substrate facing the lead electrodes, which can specifically include:

[0087] A pressure-sensitive adhesive solution with a mass concentration of 15% to 30% is drop-coated on the surface of the polymer substrate with the hollow part to obtain the adhesive layer.

[0088] The adhesive layer is attached to the side of the flexible substrate facing the lead electrodes.

[0089] It can be understood that the polymer substrate is thin and has good air permeability, and both sides of the adhesive layer can have good adhesion.

[0090] In some embodiments, the flexible substrate can include a first flexible substrate.

[0091] The lead electrodes disposed on the surface of the flexible substrate can specifically include: disposing a first lead electrode and a second lead electrode on the surface of the first flexible substrate.

[0092] The first lead electrode can include a first external electrode, a first connecting electrode, and a first active electrode. The first external electrode is rectangular, triangular, rhombic, or circular, and is used to connect with the signal acquisition device. The first active electrode is rectangular, triangular, rhombic, or circular, and is used to collect the electrooculogram signal. The first connecting electrode is rectangular, and is used to connect the first external electrode and the first active electrode.

[0093] The second lead electrode can include a second external electrode, a second connecting electrode, and a second active electrode. The second external electrode is rectangular, triangular, rhombic, or circular, and is used to connect with the signal acquisition device. The second active electrode is rectangular, triangular, rhombic, or circular, and is used to collect the electrooculogram signal. The second connecting electrode is rectangular, and is used to connect the second external electrode and the second active electrode.

[0094] The first external electrode and the second external electrode are opposite to each other along a first direction, and the first active electrode and the second active electrode are opposite to each other along the first direction. In the first direction, the distance between the first external electrode and the second external electrode is smaller than the distance between the first active electrode and the second active electrode.

[0095] It can be understood that the connection of the first external electrode and the second external electrode with the signal acquisition device can be achieved by methods known in the art. For example, the first external electrode and the second external electrode can be connected with the signal acquisition device by wired connection or wireless connection. In one example, the electrooculogram sensor can further include a lead wire, which can be used to connect the first external electrode and the signal acquisition device, and the second external electrode and the signal acquisition device, respectively.

[0096] According to the above embodiments, the first lead electrode and the second lead electrode have specific shapes, which can make the structure of the lead electrode more simple. In this way, on the one hand, the visual effect of the electrooculogram sensor can be weakened, and on the other hand, the use of electrode material can be reduced, so that the electrooculogram sensor is more light and thin, and soft. The electrooculogram sensor of the embodiments of the present application has a simple structure, is easy to mass-produce, and has the advantages of lightness, thinness, softness, and simplicity, which is conducive to realizing long-term and non-invasive measurement of electrooculogram signals.

[0097] In some embodiments, the flexible substrate may further include a second flexible substrate. Providing lead electrodes on the surface of the flexible substrate may further include: providing a third lead electrode on the surface of the first flexible substrate; and providing a fourth lead electrode on the surface of the second flexible substrate.

[0098] The above-mentioned third lead electrode may include a third external electrode, a third connecting electrode and a third active electrode. The third external electrode is rectangular, triangular, diamond or circular, and the third external electrode is used to connect to the signal acquisition device. The third active electrode is rectangular, triangular, diamond or circular, and the third active electrode is used to collect electrooculographic signals. The third connecting electrode is rectangular, and the third connecting electrode is used to connect the third external electrode and the third active electrode.

[0099] The above-mentioned fourth lead electrode may include a fourth external electrode, a fourth connecting electrode and a fourth active electrode. The fourth external electrode is rectangular, triangular, diamond or circular, and the fourth external electrode is used to connect to the signal acquisition device. The fourth active electrode is rectangular, triangular, diamond or circular, and the fourth active electrode is used to collect electrooculographic signals. The fourth connecting electrode is rectangular, and the fourth connecting electrode is used to connect the fourth external electrode and the fourth active electrode.

[0100] The fourth lead electrode is configured to be arranged opposite to the third lead electrode along a second direction, where the second direction is perpendicular to the first direction.

[0101] It is understood that the connection between the third and fourth external electrodes and the signal acquisition device can be achieved by methods known in the art. For example, the third and fourth external electrodes can be connected to the signal acquisition device via a wired connection or a wireless connection. For example, the third and fourth external electrodes can be connected to the signal acquisition device via leads.

[0102] In the above embodiment, the first flexible substrate and the second flexible substrate may be two independent components. The first flexible substrate and the first, second, and third lead electrodes disposed on a surface of the first flexible substrate may constitute a first lead component, and the second flexible substrate and the fourth lead electrode disposed on a surface of the second flexible substrate may constitute a second lead component.

[0103] Figure 1 FIG2 shows a schematic structural diagram of the first lead component 01 in the electrooculogram signal sensor provided in one embodiment of the present application.

[0104] like Figure 1 As shown, the first lead component 01 includes a first flexible substrate 10 and electrodes 20 located on the surface of the first flexible substrate 10. The electrodes 20 include a first lead electrode 21, a second lead electrode 22 and a third lead electrode 23.

[0105] The first lead electrode 21 comprises a first external electrode 21a, a first connecting electrode 21b and a first active electrode 21c. The first external electrode 21a is rectangular, triangular, rhombic or circular, and is used to connect with a signal acquisition device. The first active electrode 21c is rectangular, triangular, rhombic or circular, and is used to acquire an electro-oculogram signal. The first connecting electrode 21b is rectangular, and is used to connect the first external electrode 21a and the first active electrode 21c.

[0106] The second lead electrode 22 comprises a second external electrode 22a, a second connecting electrode 22b and a second active electrode 22c. The second external electrode 22a is rectangular, triangular, rhombic or circular, and is used to connect with a signal acquisition device. The second active electrode 22c is rectangular, triangular, rhombic or circular, and is used to acquire an electro-oculogram signal. The second connecting electrode 22b is rectangular, and is used to connect the second external electrode 22a and the second active electrode 22c.

[0107] The first external electrode 21a and the second external electrode 22a are opposite to each other along a first direction Z, and the first active electrode 21c and the second active electrode 22c are opposite to each other along the first direction Z. In the first direction Z, the interval between the first external electrode 21a and the second external electrode 22a is smaller than the interval between the first active electrode 21c and the second active electrode 22c.

[0108] The third lead electrode 23 comprises a third external electrode 23a, a third connecting electrode 23b and a third active electrode 23c. The third external electrode 23a is rectangular, triangular, rhombic or circular, and is used to connect with a signal acquisition device. The third active electrode 23c is rectangular, triangular, rhombic or circular, and is used to acquire an electro-oculogram signal. The third connecting electrode 23b is rectangular, and is used to connect the third external electrode 23a and the third active electrode 23c.

[0109] Figure 2 A structure diagram of the second lead component 02 in the electro-oculogram signal sensor is shown.

[0110] As Figure 2 shown, the second lead component 02 can comprise a second flexible substrate 30 and a fourth lead electrode 40 located on the surface of the second flexible substrate 30.

[0111] The fourth lead electrode 40 includes a fourth external electrode 40a, a fourth connection electrode 40b, and a fourth action electrode 40c. The fourth external electrode 40a is rectangular, triangular, diamond-shaped, or circular and is used to connect to a signal acquisition device. The fourth action electrode 40c is rectangular, triangular, diamond-shaped, or circular and is used to collect electrooculogram signals. The fourth connection electrode 40b is rectangular and is used to connect the fourth external electrode 40a and the fourth action electrode 40c.

[0112] The fourth lead electrode 40 is arranged opposite to the third lead electrode 23 along a second direction, and the second direction is perpendicular to the first direction Z.

[0113] In the application of the electrooculogram sensor of the above embodiment, the first lead electrode 21, the second lead electrode 22, the third lead electrode 23, and the fourth lead electrode 40 are arranged based on a bipolar lead method of a standard electrode lead method. The first lead electrode 21 and the second lead electrode 22 can form a vertical lead for detecting eye movement signals in the vertical (up and down) direction. The third lead electrode 23 and the fourth lead electrode 40 can form a horizontal lead for detecting eye movement signals in the horizontal (left and right) direction. In addition, the vertical lead and the horizontal lead cooperate with each other to detect eye movement signals in the 45° diagonal direction (upper right, upper left, lower right, lower left). Thus, eye movement can be detected in eight directions: vertical (up and down), horizontal (left and right), and 45° diagonal (upper right, upper left, lower right, lower left). By measuring blink signals during periods of wakefulness, early drowsiness, and severe fatigue, the sensor demonstrated robust electrooculogram (EOG) detection and clear discrimination. These results were reliably verified. Therefore, the EOG sensor according to the aforementioned embodiment can be used for EOG signal detection and discrimination, potentially contributing to the monitoring and prevention of driver fatigue.

[0114] In one embodiment, Figure 3 As shown, the first lead component 01 may further include a first adhesive layer 50. The first connection electrode 21b, the second connection electrode 22b, and the third connection electrode 23b may be located between the first flexible substrate 10 and the first adhesive layer 50. The first adhesive layer 50 includes a first hollow portion 51 to expose the first external electrode 21a, the second external electrode 22a, the third external electrode 23a, the first action electrode 21c, the second action electrode 22c, and the third action electrode 23c from the first adhesive layer 50. The second lead component 02 may further include a second adhesive layer 60. The fourth connection electrode 40b may be located between the second flexible substrate 30 and the second adhesive layer 60. The second adhesive layer 60 includes a second hollow portion 61 to expose the fourth external electrode 40a and the fourth action electrode 40c from the second adhesive layer 60.

[0115] In some examples, the first lead component 01 can further include a support frame 70, and the second lead component 02 can further include a support frame 70.

[0116] In some embodiments, the width d1 of the first connection electrode 21b can be 2mm-5mm.

[0117] In some embodiments, the width d2 of the second connection electrode 22b can be 2mm-5mm.

[0118] In some embodiments, the width d3 of the third connection electrode 23b can be 2mm-5mm.

[0119] In some embodiments, the width d4 of the fourth connection electrode 40b can be 2mm-5mm.

[0120] In some embodiments, the first active electrode 21c can be a circular electrode with a diameter of 5mm-10mm.

[0121] In some embodiments, the second active electrode 22c can be a circular electrode with a diameter of 5mm-10mm.

[0122] In some embodiments, the third active electrode 23c can be a circular electrode with a diameter of 5mm-10mm.

[0123] In some embodiments, the fourth active electrode 40c can be a circular electrode with a diameter of 5mm-10mm.

[0124] In some embodiments, the first outer connection electrode 21a can be a rectangular electrode with a side length of 3mm-8mm.

[0125] In some embodiments, the second outer connection electrode 22a can be a rectangular electrode with a side length of 3mm-8mm.

[0126] In some embodiments, the third outer connection electrode 23a can be a rectangular electrode with a side length of 3mm-8mm.

[0127] In some embodiments, the fourth outer connection electrode 40a can be a rectangular electrode with a side length of 3mm-8mm.

[0128] When the width of the connecting electrode, the shape and diameter of the working electrode, and the shape and side length of the outer connecting electrode are within the above suitable ranges, the lead electrode can ensure good conduction between the outer connecting electrode and the working electrode while occupying a small area. In this way, not only can the electrooculogram signal sensor have the advantages of simplicity, high integration, and low cost, but also can ensure the accuracy of electrooculogram signal measurement. In the subsequent electrooculogram signal measurement process, it is found that the electrooculogram signal sensor using the electrode structure is no longer limited to the position of the eye socket, and even stretches each lead electrode to the forehead, the nose tip, the cheek, and the left and right temples. The electrooculogram signal with obvious characteristics can also be detected, breaking the limitations of the attachment position of the electrode in the past and being more flexible to use.

[0129] It can be understood that in the electrooculogram signal sensor of the embodiments of the present application, the length of the connecting electrode can be adjusted according to actual needs. For example, when the attachment position is near the eye socket of a person, since the eye socket of a person presents a four-sided cone-shaped bone cavity, the average width between the upper and lower eye sockets of an adult is about 4-5 cm, and there is a bone curvature at the outer corner of the eye, the electrooculogram signal sensor can be a rectangle with a side length of less than or equal to 110 mm, the length of the connecting electrode can be 20-60 mm, and the width of the connecting electrode, the shape and diameter of the working electrode, and the shape and side length of the outer connecting electrode can be within the ranges of the respective embodiments described above.

[0130] The second aspect of the present application provides an electrooculogram signal sensor prepared according to the method of any one of the first aspect.

[0131] Embodiments

[0132] The following examples more specifically describe the present disclosure, which are only used for illustrative purposes, because various modifications and changes within the scope of the present disclosure are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further treatment, and the instruments used in the examples are commercially available.

[0133] Example 1

[0134] The electrooculogram signal sensor is prepared by the following steps:

[0135] A flexible substrate precursor solution with a mass concentration of 15% is prepared by taking PU as a solute and DMF as a solvent.

[0136] The first flexible substrate, the second flexible substrate, the polymer initial substrate of the first adhesive layer and the polymer initial substrate of the second adhesive layer with a thickness of 10 μm and a size of 110 mm*110 mm were prepared by an electrostatic spinning process, in which the solution was uniformly pushed and the fibers were collected at the end of a metal roller. Specifically, the syringe was adjusted to a suitable height, and the distance between the syringe and the fiber-receiving metal cylinder was set to 19 cm to ensure that the jet had enough drying distance. After adjusting the jet needle to be level with the center line of the fiber-receiving metal cylinder, the relevant parameters for spinning were set as follows: the push speed of the syringe was 0.2 mm / min, the translation speed of the syringe was 200 mm / min, and the receiving speed of the fiber-receiving metal cylinder was 60 mm / min. After "starting", the positive and negative voltage tables were turned on, and voltages of +10 kV and -0.85 kV were applied, respectively. The spinning time was about 1 h.

[0137] The first flexible substrate and the second flexible substrate were fixed on a silicon wafer, respectively, and a 200 nm metal Pt film was uniformly plated on the PU substrate by a magnetron sputtering method and a special hard mask template to complete the preparation of the electrode, thereby obtaining the first lead component and the second lead component. The human orbit presents a quadrilateral cone-shaped bone cavity, and the average width between the upper and lower orbits of an adult is about 4-5 cm. There is a bone curvature at the outer corner of the eye, so each Pt electrode (i.e., the first lead electrode to the fourth lead electrode) is composed of three parts: (1) a disc-shaped electrode with a diameter of 8 mm, which serves as an active electrode to capture the electro-oculogram signal; (2) a square-shaped external electrode with a side length of 5 mm, which is used for connecting the lead to the signal acquisition board; and (3) a connecting electrode for connecting the active electrode and the external electrode, in which the length of the vertical lead part is 60 mm, the length of the horizontal lead part is 26 mm, and the line width is 3 mm. The electrode layout of the electro-oculogram signal sensor is shown in Figure 4

[0138] The polymer initial substrate of the first adhesive layer and the polymer initial substrate of the second adhesive layer were subjected to hollowing treatment according to Figure 3 The first adhesive layer and the second adhesive layer were disposed in the first lead component and the second lead component by treating the polymer substrate of the first adhesive layer and the polymer substrate of the second adhesive layer with a PDMS / n-hexane solution with a concentration of 20%, and the electro-oculogram signal sensor was prepared according to Figure 3 The edge position and the center position of the first flexible substrate were characterized by using an optical microscope, and the obtained optical microscope images are shown in

[0139] Figures 5-6 ​​The first flexible substrate was characterized using a metallographic microscope at different magnifications (5X, scale bar 100 pm; 10X, scale bar 50 pm; 20X, scale bar 20 pm; 50X, scale bar 10 pm), and the obtained metallographic microscope images are shown in FIG. 2. Figures 7-10 The scanning electron microscope (SEM) images of the first flexible substrate were taken, and the SEM images at different magnifications (500X, 1000X) are shown in FIG. 3. Figure 11 The SEM image at 1000X magnification was processed as shown in FIG. 3(c), and the diameter of the fiber in the first flexible substrate was tested, and the test result was 2.017-2.489 pm. Figure 11 The test result of the first flexible substrate prepared by the method of the present application shows that the fiber diameter is small and uniform, and the flexible substrate has good air permeability. Figures 5-11

[0140] The external electrode leads (copper fiber) were drawn out and fixed with silver paste. Finally, the device was packaged by coating PDMS on the silver paste. The electrooculogram signal sensor was attached to the face of the subject as shown in FIG. 4. Figure 12 The electrooculogram signal sensor was attached to the face of the subject as shown in FIG. 4. The test was carried out by building an Open BCI test platform, and the electrooculogram sensor test platform can be as shown in FIG. 5. Figure 13 The eye movement was detected in 8 directions of vertical (up, down), horizontal (left, right) and 45° diagonal (right up, left up, right down, left down), and the obtained eye movement test results can be seen in FIG. 6. Figures 14-17 The eye blinking of the subject was detected in the period of wakefulness, early drowsiness and entering severe fatigue, and the test results can be seen in FIG. 7. Figures 18-19 .

[0141] Figure 14 The EOG signals of the vertical movement of the eyeball detected by the electrooculogram signal sensor are shown, wherein, Figure 14 (a) represents the EOG signal of the upward saccade, Figure 14 (b) represents the EOG signal of the downward saccade. Figure 15 The EOG signals of the horizontal movement of the eyeball detected by the electrooculogram signal sensor are shown, wherein, Figure 15 (a) represents the EOG signal of the rightward saccade, Figure 15 (b) represents the EOG signal of the leftward saccade. Figure 16 The EOG signals of the diagonal movement of the eyeball detected by the electrooculogram signal sensor are shown, wherein, Figure 16 (a) represents the EOG signal of the upward-rightward saccade, Figure 16 (b) represents the EOG signal of the upward-leftward saccade, Figure 16 (c) represents the EOG signal of the downward-rightward saccade, Figure 16 ​(d) represents the EOG signal of looking down and left.

[0142] Each eye movement direction collects 20 groups of data respectively, and the slope characteristics of each are calculated to obtain the scatter plot of eye movement slope characteristics as shown in Figure 17 The horizontal axis M H represents the slope characteristics of the horizontal eye movement signal, and the vertical axis M V represents the slope characteristics of the vertical eye movement signal. According to Figure 17 It can be seen that the slope characteristics of 8 eye movements can be clearly distinguished according to the signals detected by the electrooculogram sensor, and there is no overlapping degree.

[0143] Figure 18 The blink signals detected by the electrooculogram sensor are shown. Among them, Figure 18 (a) represents the involuntary blink signal, Figure 18 (b) represents the conscious signal, Figure 18 (c) represents the half-blink signal. Figure 19 The time domain graphs of single blink signals in the unconscious state, the conscious state and the half-blink state are shown. From Figure 19 It can be seen that the peak value of the involuntary blink signal is between 100-150 μV, and the peak values of the conscious blink and the half-blink are between 300-350 μV. At the same time, after entering the severe fatigue period, the duration of single blink is significantly increased.

[0144] From the above test results, it can be found that the electrooculogram sensor of the embodiment of the application can realize the electrooculogram detection function and has obvious distinguishing characteristics, and the obtained results have been reliably verified. Therefore, the electrooculogram sensor based on electrospinning can be used for electrooculogram signal detection and distinction, and is beneficial to the monitoring and prevention of fatigue driving.

[0145] In addition, the research on the electrooculogram sensor in the embodiment of the application is a cross-fusion direction involving multiple disciplines such as microelectronics, biomedicine, material physics, etc. The prepared new type of electrooculogram sensor can monitor in real time and efficiently, not only can detect abnormalities in the early stage of drowsiness, but also provides a new hardware design idea for fatigue driving recognition based on electrooculogram. The electrooculogram sensor according to the embodiment of the application has good biocompatibility, flexibility and stability, provides reliable technical support for non-inductive electrooculogram detection, and also injects new vitality into the EOG technology in the fields of microelectronic devices, medical diagnosis, health monitoring, etc., and shows its potential for diversified applications.

[0146] Embodiment 2

[0147] PU is used as the solute and DMF is used as the solvent to configure a flexible substrate precursor solution with a mass concentration of 5%. The electrospinning process parameters are adjusted to prepare a flexible substrate with a thickness of 50 nm and a size of 110 mm*110 mm.

[0148] The fiber diameter of the flexible substrate in Example 2 is tested, and the test result is 0.048-0.050 μm.

[0149] Example 3

[0150] PU is used as the solute and DMF is used as the solvent to configure a flexible substrate precursor solution with a mass concentration of 18%.

[0151] The electrospinning process parameters are adjusted to prepare a flexible substrate with a thickness of 5 μm and a size of 110 mm*110 mm.

[0152] The fiber diameter of the flexible substrate in Example 3 is tested, and the test result is 0.388-1.315 μm.

[0153] Example 4

[0154] PU is used as the solute and DMF is used as the solvent to configure a flexible substrate precursor solution with a mass concentration of 30%. The electrospinning process parameters are adjusted to prepare a flexible substrate with a thickness of 8 μm and a size of 110 mm*110 mm.

[0155] The fiber diameter of the flexible substrate in Example 4 is tested, and the test result is 0.386-0.776 μm.

[0156] According to the test results of Examples 2-4, the flexible substrate precursor solution can be spun by the electrospinning process to obtain a flexible substrate with a proper thickness. The flexible substrate with a proper thickness is not only light and thin, but also has a small fiber diameter, which can meet the air permeability requirement of the electrooculogram signal sensor. Therefore, it is beneficial to realize the non-inductive wearing of the electrooculogram signal sensor.

[0157] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements are all included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing an electrooculogram sensor, characterized in that: include: Providing a flexible substrate precursor solution, wherein the flexible substrate precursor solution includes a polymer and an organic solvent; The flexible substrate precursor solution is spun by an electrospinning process to obtain a flexible substrate with a thickness of 50 nm to 10 μm; Disposing a lead electrode with a thickness of 100 nm to 500 nm on the surface of the flexible substrate to obtain an electrooculogram sensor; The flexible substrate includes a first flexible substrate; The step of arranging lead electrodes on the surface of the flexible substrate comprises: arranging a first lead electrode and a second lead electrode on the surface of the first flexible substrate; The first lead electrode includes a first external electrode, a first connecting electrode, and a first active electrode. The first external electrode is rectangular, triangular, diamond, or circular, and is used to connect to a signal acquisition device. The first active electrode is rectangular, triangular, diamond, or circular, and is used to collect electrooculogram signals. The first connecting electrode is rectangular, and is used to connect the first external electrode and the first active electrode. The second lead electrode includes a second external electrode, a second connecting electrode, and a second active electrode. The second external electrode is rectangular, triangular, diamond, or circular, and is used to connect to a signal acquisition device. The second active electrode is rectangular, triangular, diamond, or circular, and is used to collect electrooculogram signals. The second connecting electrode is rectangular, and is used to connect the second external electrode and the second active electrode. The first external electrode and the second external electrode are opposite to each other along a first direction, and the first active electrode and the second active electrode are opposite to each other along the first direction; in the first direction, the distance between the first external electrode and the second external electrode is smaller than the distance between the first active electrode and the second active electrode.

2. The method according to claim 1, characterized in that The method of providing a flexible substrate precursor solution comprises: The polymer is dissolved in the organic solvent to obtain a flexible substrate precursor solution with a mass concentration of 5% to 30%.

3. The method according to claim 2, characterized in that The polymer includes one or more of polyurethane, polyethylene terephthalate, and polyimide; The organic solvent includes one or more of N,N-dimethylacetamide, N,N-dimethylformamide and chloroform.

4. The method according to any one of claims 1 to 3, characterized in that The flexible substrate includes polymer fibers with a diameter of 50 nm to 10 μm.

5. The method according to claim 1, wherein The lead electrode having a thickness of 100 nm to 500 nm is provided on the surface of the flexible substrate, comprising: A metal film is deposited on the surface of the flexible substrate according to a preset electrode pattern to form a lead electrode with a thickness of 100nm to 500nm.

6. The method according to claim 1, characterized in that After providing the lead electrodes on the surface of the flexible substrate, the method further includes: An adhesive layer having a hollow portion is provided on a side of the flexible substrate facing the lead electrode, wherein the hollow portion exposes a portion of the lead electrode.

7. The method according to claim 6, characterized in that The adhesive layer includes a polymer substrate and a pressure-sensitive layer located on the surface of the polymer substrate.

8. The method according to claim 1, characterized in that The flexible substrate further includes a second flexible substrate; and the step of arranging lead electrodes on the surface of the flexible substrate further includes: arranging a third lead electrode on the surface of the first flexible substrate; and arranging a fourth lead electrode on the surface of the second flexible substrate. The third lead electrode includes a third external electrode, a third connection electrode, and a third action electrode. The third external electrode is rectangular, triangular, diamond, or circular, and is used to connect to a signal acquisition device. The third action electrode is rectangular, triangular, diamond, or circular, and is used to collect electrooculogram signals. The third connection electrode is rectangular, and is used to connect the third external electrode and the third action electrode. The fourth lead electrode includes a fourth external electrode, a fourth connection electrode and a fourth action electrode, the fourth external electrode is rectangular, triangular, diamond or circular, and the fourth external electrode is used to connect to the signal acquisition device, the fourth action electrode is rectangular, triangular, diamond or circular, and the fourth action electrode is used to collect electrooculogram signals, the fourth connection electrode is rectangular, and the fourth connection electrode is used to connect the fourth external electrode and the fourth action electrode; The fourth lead electrode is configured to be arranged opposite to the third lead electrode along a second direction, where the second direction is perpendicular to the first direction.

9. An electrooculogram sensor prepared according to the method of any one of claims 1 to 8.

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