Flexible pressure sensor for detecting nystagmus and preparation method thereof

Abstract

The present invention discloses a flexible pressure sensor for detecting nystagmus. The sensor comprises an encapsulation layer, a non-woven fabric@Au-Ag nanofiber membrane, and interdigital electrodes stacked in sequence from top to bottom. The stacked encapsulation layer, non-woven fabric@Au-Ag nanofiber membrane, and interdigital electrodes are encapsulated, and the ends of the interdigital electrodes are connected to external testing equipment via wires. The flexible pressure sensor for detecting nystagmus solves the problem in the prior art of using non-contact eye movement video or recording for eye movement analysis, which cannot accurately detect eye tremors. The present invention also discloses a method for preparing the flexible pressure sensor for detecting nystagmus.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible sensors and relates to a flexible pressure sensor for detecting nystagmus. The present invention also relates to a method for preparing the flexible pressure sensor. Background Art

[0002] As one of the body's primary sensory organs, monitoring eye movements has unique application value. Eye movements are a primary indicator of human will and conscious choices. The human eye not only provides visual information to the brain by sensing different light sources and generating images, but also provides physiological information about the body. Eye movements contain key information about physical and mental health, emotional state, perception, intention, and preferences.

[0003] For example, when a person's eyes are tired, they will blink frequently to relieve fatigue. Secondly, the condition of the eyes can reflect the condition of the brain. Abnormal blinking and eye movements are related to brain-related diseases, such as attention deficit hyperactivity disorder (ADHA), stroke, autism, Alzheimer's disease and Parkinson's disease. In addition, eye movements are related to two sleep modes, non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep, which are closely related to brain development. Therefore, by monitoring eye movements, we can further study the development of the human brain, perception and psychological state, etc., which is of great significance in preventing some sudden diseases.

[0004] Existing technologies all use non-contact eye movement videos or recordings to analyze eye movements, which has poor accuracy and cannot accurately detect eye vibrations, let alone accurately determine neurological diseases presenting in the eyes through eye vibrations. Summary of the Invention

[0005] The purpose of the present invention is to provide a flexible pressure sensor for detecting nystagmus, which solves the problem in the prior art that eye movement analysis using non-contact eye movement videos or recordings cannot accurately detect eye nystagmus.

[0006] Another object of the present invention is to provide a method for preparing a flexible pressure sensor for detecting nystagmus.

[0007] The technical solution adopted by the present invention is a flexible pressure sensor for detecting nystagmus, which includes a packaging layer, a non-woven fabric @Au-Ag nanofiber membrane, and an interdigital electrode stacked in sequence from top to bottom. The stacked packaging layer, non-woven fabric @Au-Ag nanofiber membrane, and interdigital electrodes are packaged and the two ends of the interdigital electrodes are connected to external testing equipment through wires.

[0008] Another technical solution adopted by the present invention is a method for preparing a flexible pressure sensor for detecting nystagmus, which is specifically implemented according to the following steps:

[0009] Step 1: soak the non-woven fabric membrane in a chloroauric acid solution, wash the surface with deionized water, soak it in a sodium borohydride solution, and rinse it with deionized water to obtain a NWFs / Au nanofiber membrane;

[0010] Step 2: PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid are added to deionized water to obtain a growth solution. The NWFs / Au nanofiber membrane obtained in step 1 is placed in the growth solution under certain conditions and stirred, and then washed with deionized water to obtain a non-woven fabric@Au-Ag nanofiber membrane.

[0011] In step 3, the packaging layer, non-woven fabric @Au-Ag nanofiber membrane, and interdigital electrodes are stacked and packaged from top to bottom, wherein both ends of the interdigital electrodes are connected with wires to complete the preparation of the flexible pressure sensor based on non-woven fabric @Au-Ag nanofiber membrane.

[0012] In step 1, the non-woven fabric membrane is immersed in the chloroauric acid solution. Specifically, the non-woven fabric membrane is immersed in chloroauric acid with a concentration of 0.02-0.03 mM for 1-5 minutes.

[0013] In step 1, the non-woven fabric membrane is immersed in a chloroauric acid solution and then washed with deionized water to remove the surface, and then immersed in a sodium borohydride solution. The immersion in sodium borohydride in step 1 is specifically: immersed in sodium borohydride with a concentration of 0.02-0.03mM for 1-5 minutes. The operation of immersing in the sodium borohydride solution in step 1 and then washing with deionized water to remove the surface is repeated at least 3 times to obtain a multi-cycle NWFs / Au nanofiber membrane;

[0014] In step 2, the addition ratio of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid is 10 ml: 1-2 ml: 1-2 ml: 1-2 ml: 0.5-1 ml: 0.5-1 ml.

[0015] The concentration of the PVP solution added in step 2 is 5-10 wt.%, the concentration of AgNO3 added is 0.1-1 mM, and the concentration of ascorbic acid added in step 2 is 0.1-1 mM.

[0016] In step 2, the NWFs / Au nanofiber membrane obtained in step 1 is placed in a growth solution under certain conditions and stirred. Specifically, the NWFs / Au nanofiber membrane obtained in step 1 is placed in a growth solution at a temperature of 4-10° C. and stirred at a rate of 200 revolutions per minute for 10-40 minutes.

[0017] In step 2, the NWFs / Au nanofiber membrane is placed in the growth liquid under certain conditions and stirred. After being taken out, it is placed in the growth liquid again under certain conditions and stirred. This cycle is repeated at least 3 times to obtain a non-woven fabric @Au-Ag nanofiber membrane that has undergone multiple cycles of growth. The non-woven fabric @Au-Ag nanofiber membrane is then washed with deionized water and dried at room temperature.

[0018] The encapsulation layer in step 3 is a flexible substrate.

[0019] The beneficial effects of the present invention are:

[0020] The flexible pressure sensor for detecting nystagmus of the present invention provides a guarantee for contact detection of eye vibration. When the flexible pressure sensor for detecting nystagmus of the present invention is used for detection, the flexible pressure sensor for detecting nystagmus of the present invention is attached to the eyelid, lower eyelid, temple, and inner canthus. When the eyeball is tested by looking up and down, left and right, the pressure applied to the sensor by the muscles around the eye and the eyeball also changes with the change of the eyeball movement state. The flexible pressure sensor can sense the pressure change of the eyeball movement. The waveform of the test curve of the flexible pressure sensor attached to the upper eyelid is more obvious, and the current signal changes greatly. The force exerted by the eyeball on the flexible pressure sensor at the upper eyelid is greater, so the current waveform of the upper eyelid changes more; when attached to the temple and inner canthus, the current signal changes very little, which shows that the flexible pressure sensor of the present invention can accurately detect eye vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a non-woven fabric membrane used in the method for preparing a flexible pressure sensor for detecting nystagmus according to the present invention;

[0022] Figure 2 is a microscopic SEM microscopic image of a non-woven fabric membrane used in the method for preparing a flexible pressure sensor for detecting nystagmus of the present invention;

[0023] Figure 3 This is a microscopic SEM micrograph of a NWFs / Au nanofiber membrane prepared in three cycles in an embodiment of the method for preparing a flexible pressure sensor for detecting nystagmus of the present invention;

[0024] Figure 4 This is a microscopic SEM micrograph of a non-woven fabric@Au-Ag nanofiber membrane prepared by three cycles in an embodiment of the method for preparing a flexible pressure sensor for detecting nystagmus of the present invention;

[0025] Figure 5 1. The XRD patterns of the non-woven fabric membrane, the NWFs / Au nanofiber membrane prepared by three cycles, and the non-woven fabric@Au-Ag nanofiber membrane in the embodiment of the method for preparing a flexible pressure sensor for detecting nystagmus of the present invention;

[0026] Figure 6 1 is a schematic structural diagram of a flexible pressure sensor for detecting nystagmus according to the present invention;

[0027] Figure 7 This is a diagram of the distribution of muscles around the eyes;

[0028] Figure 8 This is a blinking curve diagram when the eyes are open using the non-woven fabric@Au-Ag fiber membrane flexible pressure sensor of the present invention;

[0029] Figure 9 This is a blinking curve diagram when the eyes are closed using the non-woven fabric@Au-Ag fiber membrane flexible pressure sensor of the present invention;

[0030] Figure 10 This is a microscopic SEM micrograph of a NWFs / Au nanofiber membrane prepared in 6 cycles in an embodiment of the method for preparing a flexible pressure sensor for detecting nystagmus of the present invention;

[0031] Figure 11 This is a microscopic SEM micrograph of a non-woven fabric@Au-Ag nanofiber membrane prepared in 6 cycles in an embodiment of the method for preparing a flexible pressure sensor for detecting nystagmus of the present invention;

[0032] Figure 12a This is a blink signal monitoring curve obtained by attaching the flexible pressure sensor for detecting nystagmus prepared in Example 2 of the present invention to the upper eyelid;

[0033] Figure 12b This is a blink signal monitoring curve obtained by attaching the flexible pressure sensor for detecting nystagmus prepared in Example 2 of the present invention to the lower eyelid;

[0034] Figure 12c This is a blink signal monitoring curve obtained by attaching the flexible pressure sensor for detecting nystagmus prepared in Example 2 of the present invention to the temple;

[0035] Figure 12d This is a blink signal monitoring curve obtained by attaching the flexible pressure sensor for detecting nystagmus prepared in Example 2 of the present invention to the inner canthus;

[0036] Figure 13 This is a microscopic SEM micrograph of a NWFs / Au nanofiber membrane prepared in 9 cycles in an embodiment of the method for preparing a flexible pressure sensor for detecting nystagmus of the present invention;

[0037] Figure 14 This is a microscopic SEM micrograph of a non-woven fabric@Au-Ag nanofiber membrane prepared by 9 cycles in an embodiment of the method for preparing a flexible pressure sensor for detecting nystagmus of the present invention;

[0038] Figure 15a The current response curve of the flexible pressure sensor for detecting nystagmus prepared by Example 3 of the present invention attached to the upper eyelid during the process of opening, half-closing, closing, and opening the eyes;

[0039] Figure 15b The current response curve of the flexible pressure sensor for detecting nystagmus prepared by Example 3 of the present invention attached to the lower eyelid during the process of opening, half-closing, closing, and opening the eyes;

[0040] Figure 15c The current response curve of the flexible pressure sensor for detecting nystagmus prepared by Example 3 of the present invention attached to the temple during the process of eyes opening, half-closing, closing, and opening;

[0041] Figure 15d The current response curve of the flexible pressure sensor for detecting nystagmus prepared by Example 3 of the present invention attached to the inner canthus during the process of eye opening, half-closed, closed, and open;

[0042] Figure 16a It is a diagram of the eyes with eyes closed and eyes open;

[0043] Figure 16b This is a signal curve diagram of the eye closing-eye opening process detected by the flexible pressure sensor for detecting nystagmus prepared by Example 3 of the present invention;

[0044] Figure 17a It is a diagram showing eye movements with the eyes looking up and down;

[0045] Figure 17b It is a diagram showing eye movements as eyes looking left and right;

[0046] Figure 18a The flexible pressure sensor for detecting nystagmus prepared in Example 5 of the present invention is attached to the upper and lower eyelids to show the eye movement response curve when looking up and down;

[0047] Figure 18b The flexible pressure sensor for detecting nystagmus prepared by Example 5 of the present invention is attached to the temple and inner canthus to generate an eye movement response curve when looking up and down;

[0048] Figure 19a The flexible pressure sensor for detecting nystagmus prepared by Example 6 of the present invention is attached to the upper and lower eyelids to show the response curve of eye movement when looking left and right;

[0049] Figure 19b The flexible pressure sensor for detecting nystagmus prepared by Example 6 of the present invention is attached to the temple and inner canthus to generate a response curve for looking left and right.

[0050] Figure 20a This is a response curve diagram of a sleep eye movement test using the flexible pressure sensor for detecting nystagmus prepared in Example 7 of the present invention;

[0051] Figure 20b for Figure 20a A partial enlarged view of . DETAILED DESCRIPTION

[0052] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] The flexible pressure sensor for detecting nystagmus of the present invention has a structure as follows Figure 6 As shown, the device includes, from top to bottom, an encapsulation layer, a nonwoven fabric@Au-Ag nanofiber membrane, and interdigital electrodes. The stacked encapsulation layer, nonwoven fabric@Au-Ag nanofiber membrane, and interdigital electrodes are encapsulated, and the ends of the interdigital electrodes are connected to external testing equipment via wires. The flexible substrate of the encapsulation layer is cotton fiber cloth, silk fiber cloth, PDMS membrane, or nylon fiber cloth.

[0054] The method for preparing a flexible pressure sensor for detecting nystagmus of the present invention is specifically as follows:

[0055] Step 1: soak the non-woven fabric membrane in a 0.02-0.03 mM chloroauric acid solution for 1-5 minutes, remove it and wash the surface with deionized water, repeat the process of soaking in the chloroauric acid solution and washing the surface with deionized water for at least 3 times, then soak it in a 0.02-0.03 mM sodium borohydride solution for 1-5 minutes, remove it and rinse it with deionized water, repeat the process of soaking in the sodium borohydride solution and rinsing with deionized water for at least 3 times to obtain a multi-cycle NWFs / Au nanofiber membrane;

[0056] Step 2, adding PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid to deionized water to obtain a growth solution, wherein the addition ratio of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid is 10ml: 1-2ml: 1-2ml: 1-2ml: 0.5-1ml: 0.5-1ml, the concentration of PVP solution is 5-10wt.%, the concentration of AgNO3 is 0.1-1mM, and the concentration of ascorbic acid is 0.1-1mM. The NWFs / Au nanofiber membrane obtained in step 1 is placed in the growth solution at a rate of 200 revolutions per minute under an environment of 4-10°C and stirred for 10-40 minutes. After taking it out, it is continued to be placed in the growth solution under certain conditions and stirred. This cycle is repeated for at least 3 times to obtain a non-woven fabric @Au-Ag nanofiber membrane that has been grown for multiple cycles, and then the non-woven fabric @Au-Ag nanofiber membrane is washed with deionized water and dried at room temperature;

[0057] In step 3, the encapsulation layer, the non-woven fabric @Au-Ag nanofiber membrane, and the interdigital electrodes are stacked and encapsulated from top to bottom, wherein both ends of the interdigital electrodes are connected with wires to complete the preparation of the flexible pressure sensor based on the non-woven fabric @Au-Ag nanofiber membrane. The encapsulation layer is a flexible substrate, which can be a fiber cloth or a soft polymer membrane. The interdigital electrodes are connected to the non-woven fabric @Au-Ag fiber membrane to form a working circuit. When in use, the wires at both ends of the interdigital electrodes are used to connect external test equipment. The interdigital electrodes of the present invention can adopt a circular or rectangular structure.

[0058] The sensor of the present invention is used to monitor eye movements. The present invention adopts the eye test movements of looking up and down and looking left and right, and selects four positions to fit the flexible pressure sensor based on non-woven fabric @Au-Ag nanofiber membrane prepared by the present invention to monitor the eye movement status. When the eye moves up and down or left and right, the pressure applied to the sensor by the muscles around the eye and the eye also changes with the change of the eye movement state. The flexible pressure sensor can sense the pressure change of the eye movement. The waveform of the test curve of the flexible pressure sensor attached to the upper eyelid is more obvious, and the current signal changes greatly. The force exerted by the eye on the flexible pressure sensor at the upper eyelid is greater, so the current waveform of the upper eyelid changes more; when attached to the temple and inner canthus, the current signal changes very little.

[0059] The non-woven membrane used in the embodiment of the present invention is as follows Figure 1 As shown in the SEM micrograph of the nonwoven membrane, Figure 2 As shown;

[0060] Example 1

[0061] A method for preparing a flexible pressure sensor for detecting nystagmus specifically comprises the following steps:

[0062] Step 1: Place the non-woven membrane in a 0.02 mM chloroauric acid solution for 1 minute. Figure 1-2 As shown, after taking it out, the surface was washed with deionized water, and after three cycles, it was placed in a 0.02mM sodium borohydride solution for 1 minute, taken out and rinsed with deionized water. After three cycles, a 3-cycle NWFs / Au nanofiber membrane was obtained, as shown Figure 3 As shown;

[0063] Step 2: Add a certain amount of PVP solution with a mass fraction of 5 wt.%, acetonitrile, ethanol, AgNO3 with a concentration of 0.1 mM, and ascorbic acid with a concentration of 0.1 mMd to deionized water. The added volumes of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid are 20 ml, 4 ml, 4 ml, 4 ml, 2 ml, and 2 ml, respectively. At 10 ° C, the non-woven fabric @ Au seed nanofiber membrane is added to the growth solution and stirred at a rate of 200 rpm for 20 minutes. The cycle is repeated 3 times to obtain a non-woven fabric @ Au-Ag nanofiber membrane grown for 3 cycles, as shown in FIG. Figure 4 As shown, the non-woven fabric@Au-Ag nanofiber membrane was washed with deionized water and dried at room temperature; Au and Ag elements were deposited on the surface of the non-woven fabric and the surface modification of the flexible fiber membrane was completed, as shown in FIG. Figure 5 As shown in the XRD pattern;

[0064] Step 3: Encapsulate the flexible substrate, non-woven fabric @Au-Ag nanofiber membrane, interdigital electrodes, and wires connected to external tests to complete the preparation of the flexible pressure sensor based on non-woven fabric @Au-Ag fiber membrane, as shown in the following figure: Figure 6 As shown;

[0065] The non-woven fabric@Au-Ag fiber membrane flexible pressure sensor prepared in this embodiment is used to monitor neurological nystagmus signals. In this embodiment, the non-woven fabric@Au-Ag fiber membrane flexible pressure sensor is attached to the upper eyelid to conduct an artificial blinking experiment. Figure 7 The test results are shown in Figure 8 、 Figure 9 As shown in the figure, it can be clearly seen that when wearing the flexible pressure sensor in two different states, the change trend of the current signal is roughly the same, and the test curve shows consistent regularity. The current of the flexible pressure sensor increases when pressure is applied and decreases when the pressure is released. The difference is that when wearing it with eyes open, the current increases when the eyes are closed and the current decreases when the eyes are opened. When testing with eyes closed, a sudden increase in current indicates the occurrence of eye opening, and a sudden decrease in current indicates the occurrence of eye closing. The flexible pressure sensor can respond sensitively to eye blinking.

[0066] Example 2

[0067] A method for preparing a flexible pressure sensor for detecting nystagmus specifically comprises the following steps:

[0068] Step 1: Place the non-woven fabric membrane in 0.02mM chloroauric acid for 1 minute, take it out and rinse the surface with deionized water. After 6 cycles, place it in 0.02mM sodium borohydride for 1 minute, take it out and rinse it with deionized water. After 6 cycles, a 6-cycle NWFs / Au nanofiber membrane is obtained. Figure 10 As shown;

[0069] Step 2: Add a certain amount of 5wt.% PVP solution, acetonitrile, ethanol, 0.1mM AgNO3, and 0.1mMd ascorbic acid to deionized water. The addition ratios of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid are 20ml, 2ml, 2ml, 2ml, 1ml, and 1ml. At 10°C, add the non-woven fabric @Au seed nanofiber membrane to the growth solution and stir at a rate of 200 rpm for 10 minutes. After 6 cycles, a non-woven fabric @Au-Ag nanofiber membrane that has undergone 6 cycles is obtained. The non-woven fabric @Au-Ag nanofiber membrane is washed with deionized water and dried at room temperature. Au and Ag elements are deposited on the surface of the non-woven fabric and the surface modification of the flexible fiber membrane is completed.

[0070] Step 3: Encapsulate the flexible substrate, the obtained non-woven fabric @Au-Ag nanofiber membrane, the interdigital electrodes, and the wires connected to the external test together to complete the preparation of the flexible pressure sensor based on the non-woven fabric @Au-Ag fiber membrane. The interdigital electrodes are connected to the non-woven fabric @Au-Ag fiber membrane to form a working circuit, such as Figure 6 As shown;

[0071] The non-woven fabric @Au-Ag fiber membrane flexible pressure sensor of this embodiment is used to monitor the neurological nystagmus signal. In this embodiment, the flexible pressure sensor is attached to the upper eyelid, lower eyelid, temple, and inner canthus to monitor the blink signal. The test results are as follows: Figures 12a-12d As shown in the figure, the flexible pressure sensor can respond to the tiny pressures on the muscles around the eyes as they contract and relax during blinking. The sensor's current changes with the blink signal over a period of 0 to 40 seconds, with each current pulse waveform representing a complete blink.

[0072] Example 3

[0073] A method for preparing a flexible pressure sensor for detecting nystagmus specifically comprises the following steps:

[0074] Step 1: Place the non-woven fabric membrane in 0.02mM chloroauric acid for 1 minute, take it out and rinse the surface with deionized water, cycle it 9 times, then place it in 0.02mM sodium borohydride for 1 minute, take it out and rinse it with deionized water, cycle it 9 times, and obtain a 9-cycle NWFs / Au nanofiber membrane. Figure 13 As shown;

[0075] Step 2: Add a certain amount of 5 wt.% PVP solution, acetonitrile, ethanol, 0.1 mM AgNO3, and 0.1 mM ascorbic acid to deionized water. The addition ratios of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid are 20 ml, 3 ml, 3 ml, 3 ml, 1.6 ml, and 1.6 ml. At 10 ° C, the non-woven fabric @ Au seed nanofiber membrane is added to the growth solution and stirred at a rate of 200 rpm for 40 minutes. After 9 cycles, a non-woven fabric @ Au-Ag nanofiber membrane grown after 9 cycles is obtained, as shown in FIG. Figure 14 As shown, the non-woven fabric@Au-Ag nanofiber membrane was washed with deionized water and dried at room temperature; Au and Ag elements were deposited on the surface of the non-woven fabric and the surface modification of the flexible fiber membrane was completed;

[0076] Step 3: Encapsulate the flexible substrate, non-woven fabric @Au-Ag nanofiber membrane, interdigital electrodes, and wires connected to external tests to complete the preparation of the flexible pressure sensor based on non-woven fabric @Au-Ag fiber membrane, as shown in the following figure: Figure 6 As shown;

[0077] The non-woven fabric@Au-Ag fiber membrane flexible pressure sensor of this embodiment is used to monitor neurological nystagmus signals. This embodiment tests the blink signal amplification curves of different attachment positions, such as Figure 15a-Figure 15d As shown in the figure, it is clear that the current signal measured by the sensor attached to the upper eyelid is more stable and has a strong regularity. The rate of change of the current signal is greater during blinking. The other three parts can respond to blinking, but the current signal changes less. This indicates that the muscles around the eyes generate different micro-pressures during blinking, which in turn indicates that the muscles around the eyes have different degrees of influence on blinking and play different roles in the blinking process.

[0078] Example 4

[0079] A method for preparing a flexible pressure sensor for detecting nystagmus specifically comprises the following steps:

[0080] Step 1: Place the non-woven fabric membrane in 0.02mM chloroauric acid for 1 minute, take it out and rinse the surface with deionized water. After 6 cycles, place it in 0.02mM sodium borohydride for 1 minute, take it out and rinse it with deionized water. After 6 cycles, a 6-cycle NWFs / Au nanofiber membrane is obtained, as shown in the figure. Figure 10 As shown;

[0081] Step 2: Add a certain amount of 5 wt.% PVP solution, acetonitrile, ethanol, 0.1 mM AgNO3, and 0.1 mM ascorbic acid to deionized water. The addition ratios of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid are 30 ml, 3 ml, 3 ml, 3 ml, 1.5 ml, and 1.5 ml. At 10 ° C, the non-woven fabric @ Au seed nanofiber membrane is added to the growth solution and stirred at a rate of 200 rpm for 30 minutes. After 6 cycles, a non-woven fabric @ Au-Ag nanofiber membrane grown after 6 cycles is obtained. Figure 11 As shown. The non-woven fabric@Au-Ag nanofiber membrane was washed with deionized water and dried at room temperature. Au and Ag elements were deposited on the surface of the non-woven fabric and the surface modification of the flexible fiber membrane was completed.

[0082] Step 3: Encapsulate the flexible substrate, non-woven fabric @Au-Ag nanofiber membrane, interdigital electrodes, and wires connected to external tests to complete the preparation of the flexible pressure sensor based on non-woven fabric @Au-Ag fiber membrane, as shown in the following figure: Figure 6 shown

[0083] The non-woven fabric @Au-Ag fiber membrane flexible pressure sensor of this embodiment is used to monitor neurological nystagmus signals. This embodiment tests the eye-closing and eye-opening signals. From the magnified diagram of the blinking current signal, it can be seen that when the eyes are closed, the current increases; when the eyes are open, the current signal decreases. The blinking current signals at four locations around the eyes all show consistent regularity. This is because when the eyes are closed, the resistance of the flexible pressure sensor decreases and the current increases, while when the eyes are open, the resistance of the flexible pressure sensor increases and the current decreases, as shown in Figure 16. Therefore, this flexible pressure sensor can more accurately sense and identify the state of the muscles around the eyes when blinking, and blink recognition can be further applied to the detection of the health status of the muscles around the eyes.

[0084] Example 5

[0085] A method for preparing a flexible pressure sensor for detecting nystagmus specifically comprises the following steps:

[0086] Step 1: Place the non-woven fabric membrane in 0.02mM chloroauric acid for 1 minute, take it out and rinse the surface with deionized water. After 6 cycles, place it in 0.02mM sodium borohydride for 1 minute, take it out and rinse it with deionized water. After 6 cycles, a 6-cycle NWFs / Au nanofiber membrane is obtained, as shown in the figure. Figure 10 As shown;

[0087] Step 2: Add a certain amount of 5 wt.% PVP solution, acetonitrile, ethanol, 0.1 mM AgNO3, and 0.1 mM ascorbic acid to deionized water. The addition ratios of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid are 20 ml, 4 ml, 2 ml, 4 ml, 2 ml, and 2 ml. At 10 ° C, the non-woven fabric @ Au seed nanofiber membrane is added to the growth solution and stirred at a rate of 200 rpm for 20 minutes. After 6 cycles, a non-woven fabric @ Au-Ag nanofiber membrane grown after 6 cycles is obtained, as shown in FIG. Figure 11 As shown. The non-woven fabric@Au-Ag nanofiber membrane was washed with deionized water and dried at room temperature. Au and Ag elements were deposited on the surface of the non-woven fabric and the surface modification of the flexible fiber membrane was completed.

[0088] Step 3: Encapsulate the flexible substrate, non-woven fabric @Au-Ag nanofiber membrane, interdigital electrodes, and wires connected to external tests to complete the preparation of the flexible pressure sensor based on non-woven fabric @Au-Ag fiber membrane. The structure is as follows: Figure 6 As shown;

[0089] The non-woven fabric@Au-Ag fiber membrane flexible pressure sensor of this embodiment is used to monitor the neurological nystagmus signal. This embodiment designs an eye test action of looking up and down, such as Figure 17a 、 Figure 18a 、 Figure 18b As shown in the figure, four locations are also selected to fit flexible pressure sensors to monitor eye movement. When the eye moves up and down, the pressure applied by the muscles around the eye and the eye to the sensor also changes with the change of the eye movement state. Figure 18a and 18b As shown, the flexible pressure sensor can sense pressure changes caused by eye movement. The figure shows that the test curve for the flexible pressure sensor attached to the upper eyelid has a more pronounced waveform and a larger current signal variation. This is likely because the flexible pressure sensor is in direct contact with the eyeball when attached to the upper eyelid, and the eyeball exerts a greater force on the flexible pressure sensor at the upper eyelid, resulting in a larger change in the current waveform. When attached to the temple and inner canthus, the current signal changes very little.

[0090] Example 6

[0091] A method for preparing a flexible pressure sensor for detecting nystagmus specifically comprises the following steps:

[0092] Step 1: Place the non-woven fabric membrane in 0.02mM chloroauric acid for 1 minute, take it out and rinse the surface with deionized water. After 6 cycles, place it in 0.02mM sodium borohydride for 1 minute, take it out and rinse it with deionized water. After 6 cycles, a 6-cycle NWFs / Au nanofiber membrane is obtained, as shown in the figure. Figure 10As shown;

[0093] Step 2: Add a certain amount of 5 wt.% PVP solution, acetonitrile, ethanol, 0.1 mM AgNO3, and 0.1 mM ascorbic acid to deionized water. The addition ratios of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid are 20 ml, 2 ml, 4 ml, 4 ml, 1 ml, and 2 ml. At 10 ° C, the non-woven fabric @ Au seed nanofiber membrane is added to the growth solution and stirred at a rate of 200 rpm for 40 minutes. After 6 cycles, a non-woven fabric @ Au-Ag nanofiber membrane grown after 6 cycles is obtained. Figure 11 As shown, the non-woven fabric@Au-Ag nanofiber membrane was washed with deionized water and dried at room temperature; Au and Ag elements were deposited on the surface of the non-woven fabric and the surface modification of the flexible fiber membrane was completed;

[0094] Step 3: Encapsulate the flexible substrate, non-woven fabric @Au-Ag nanofiber membrane, interdigital electrodes, and wires connected to external tests to complete the preparation of the flexible pressure sensor based on non-woven fabric @Au-Ag fiber membrane, as shown in the following figure: Figure 6 As shown;

[0095] Step 4: Non-woven fabric@Au-Ag fiber membrane flexible pressure sensor monitors neurological nystagmus signals. This embodiment designs the eye test action of looking left and right, such as Figure 17b 、 Figure 19a 、 Figure 19b As shown in the figure, four locations are also selected to fit flexible pressure sensors to monitor eye movement. When the eye moves left and right, the pressure applied by the muscles around the eye and the eye to the sensor also changes with the change of eye movement. Figure 19a and Figure 19b As shown, the flexible pressure sensor can sense pressure changes caused by eye movement. The figure shows that the test curve for the flexible pressure sensor attached to the upper eyelid has a more pronounced waveform and a larger current signal variation. This is likely because the flexible pressure sensor is in direct contact with the eyeball when attached to the upper eyelid, and the eyeball exerts a greater force on the flexible pressure sensor at the upper eyelid, resulting in a larger change in the current waveform. When attached to the temple and inner canthus, the current signal changes very little.

[0096] Example 7

[0097] A method for preparing a flexible pressure sensor for detecting nystagmus specifically comprises the following steps:

[0098] Step 1: Place the nonwoven membrane in 0.02 mM chloroauric acid for 1 minute, take it out and rinse the surface with deionized water. After 6 cycles, place it in 0.02 mM sodium borohydride for 1 minute, take it out and rinse it with deionized water. Repeat 6 cycles to obtain a 6-cycle NWFs / Au nanofiber membrane. Figure 10 As shown;

[0099] Step 2: Add a certain amount of PVP solution with a mass fraction of 5 wt.%, acetonitrile, ethanol, AgNO3 with a concentration of 0.1 mM, and ascorbic acid with a concentration of 0.1 mMd to deionized water. The addition ratios of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid are 20 ml, 4 ml, 4 ml, 4 ml, 1 ml, and 1 ml. At 10 ° C, the non-woven fabric @ Au seed nanofiber membrane is added to the growth solution and stirred at a rate of 200 rpm for 30 minutes, and 6 cycles are performed to obtain a non-woven fabric @ Au-Ag nanofiber membrane grown after 6 cycles, as shown in FIG. Figure 11 As shown. The non-woven fabric@Au-Ag nanofiber membrane was washed with deionized water and dried at room temperature. Au and Ag elements were deposited on the surface of the non-woven fabric and the surface modification of the flexible fiber membrane was completed.

[0100] Step 3: Encapsulate the flexible substrate, non-woven fabric @Au-Ag nanofiber membrane, interdigital electrodes, and wires connected to external tests to complete the preparation of the flexible pressure sensor based on non-woven fabric @Au-Ag fiber membrane, as shown in the following figure: Figure 6 As shown;

[0101] The non-woven fabric @Au-Ag fiber membrane flexible pressure sensor of this embodiment is used to monitor neurological nystagmus signals. As people's pace of life accelerates, sleep quality has become a hot topic of concern. Sleep quality is closely related to human health. Low-quality sleep not only affects the state of the whole day, but also reduces human immunity and physical fitness in the long run, thereby increasing the incidence of various diseases. Studies have found that a sleep cycle is mainly divided into five stages: drowsiness, light sleep, medium-deep sleep, deep sleep, and rapid eye movement sleep. The first four stages are non-rapid eye movement stages, and the entire sleep cycle is a continuous cycle between non-rapid eye movement (NREMS) and rapid eye movement (REM). During the rapid eye movement period, the eyeballs will show rapid eye saccades. Therefore, a flexible pressure sensor can be used to monitor eye movements during sleep, thereby monitoring and analyzing sleep quality. As Figure 20a As shown, a flexible pressure sensor is attached to the inside of an eye mask. When the subject wears the eye mask, the flexible pressure sensor adheres to the upper eyelid and monitors pressure changes between the eye mask and the eye caused by eye movement. The subject simulates rapid eye movement (REM) sleep by moving their eyes. Figure 20aThe rapid eye movement signals of the test subjects were recorded in the figure. As can be seen from the figure, the pressure applied to the flexible pressure sensor during eye movement changes with the eye movement. Figure 20b The current signal amplification curve shows that when the eyeball exerts pressure on the flexible sensor, the sensor's resistance decreases and the current increases. Therefore, this flexible pressure sensor can respond to eye movements during sleep and has great application potential in sleep quality monitoring.

[0102] The present invention designs and prepares a non-woven fabric@Au-Ag fiber membrane flexible pressure sensor to detect neurological physiological processes such as telekinesis and blinking of the human eyeball.

[0103] Example 8

[0104] The method for preparing the flexible pressure sensor for detecting nystagmus of the present invention is specifically implemented according to the following steps:

[0105] Step 1: soak the non-woven fabric membrane in a 0.03 mM chloroauric acid solution for 3 minutes, remove it and wash the surface with deionized water, repeat the soaking in chloroauric acid solution - washing the surface with deionized water for at least 3 times, then soak it in a 0.03 mM sodium borohydride solution for 3 minutes, remove it and rinse it with deionized water, repeat the soaking in sodium borohydride solution - rinsing with deionized water for at least 3 times to obtain a multi-cycle NWFs / Au nanofiber membrane;

[0106] Step 2, adding PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid to deionized water to obtain a growth solution, wherein the addition ratio of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid is 10ml:2ml:2ml:2ml:1ml:1ml, the concentration of PVP solution is 10wt.%, the concentration of AgNO3 is 1mM, and the concentration of ascorbic acid is 1mM. The NWFs / Au nanofiber membrane obtained in step 1 is placed in the growth solution at 10°C and stirred at a rate of 200 rpm for 10 minutes. After taking it out, it is continued to be placed in the growth solution under certain conditions and stirred. This cycle is repeated for at least 3 times to obtain a non-woven fabric @Au-Ag nanofiber membrane that has been grown for multiple cycles, and then the non-woven fabric @Au-Ag nanofiber membrane is washed with deionized water and dried at room temperature;

[0107] In step 3, the packaging layer, non-woven fabric @Au-Ag nanofiber membrane, and interdigital electrodes are stacked and packaged from top to bottom, wherein both ends of the interdigital electrodes are connected with wires to complete the preparation of the flexible pressure sensor based on the non-woven fabric @Au-Ag nanofiber membrane. The packaging layer is a flexible substrate, which can be a fiber cloth or a soft polymer membrane. The interdigital electrodes are connected to the non-woven fabric @Au-Ag fiber membrane to form a working circuit.

[0108] Example 9

[0109] The method for preparing the flexible pressure sensor for detecting nystagmus of the present invention is specifically implemented according to the following steps:

[0110] Step 1: soak the non-woven fabric membrane in a 0.02 mM chloroauric acid solution for 5 minutes, remove it and wash the surface with deionized water, repeat the soaking in chloroauric acid solution - washing the surface with deionized water for at least 3 times, then soak it in a 0.02 mM sodium borohydride solution for 5 minutes, remove it and rinse it with deionized water, repeat the soaking in sodium borohydride solution - washing with deionized water for at least 3 times to obtain a multi-cycle NWFs / Au nanofiber membrane;

[0111] Step 2, adding PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid to deionized water to obtain a growth solution, wherein the addition ratio of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid is 10ml:1ml:1ml:1ml:0.5ml:0.5ml, the concentration of PVP solution is 5wt.%, the concentration of AgNO3 is 1mM, and the concentration of ascorbic acid is 1mM. The NWFs / Au nanofiber membrane obtained in step 1 is placed in the growth solution at 8°C and stirred at a rate of 200 rpm for 30 minutes. After taking it out, it is continued to be placed in the growth solution under certain conditions and stirred. This cycle is repeated for at least 3 times to obtain a non-woven fabric @Au-Ag nanofiber membrane that has been grown for multiple cycles, and then the non-woven fabric @Au-Ag nanofiber membrane is washed with deionized water and dried at room temperature;

[0112] In step 3, the packaging layer, non-woven fabric @Au-Ag nanofiber membrane, and interdigital electrodes are stacked and packaged from top to bottom, wherein both ends of the interdigital electrodes are connected with wires to complete the preparation of the flexible pressure sensor based on the non-woven fabric @Au-Ag nanofiber membrane. The packaging layer is a flexible substrate, which can be a fiber cloth or a soft polymer membrane. The interdigital electrodes are connected to the non-woven fabric @Au-Ag fiber membrane to form a working circuit.

[0113] Example 10

[0114] The preparation method of the flexible pressure sensor for detecting nystagmus is specifically implemented according to the following steps:

[0115] Step 1: soak the non-woven fabric membrane in a 0.025 mM chloroauric acid solution for 3 minutes, remove it and wash the surface with deionized water, repeat the soaking in chloroauric acid solution - washing the surface with deionized water for at least 3 times, then soak it in a 0.025 mM sodium borohydride solution for 3 minutes, remove it and rinse it with deionized water, repeat the soaking in sodium borohydride solution - washing with deionized water for at least 3 times to obtain a multi-cycle NWFs / Au nanofiber membrane;

[0116] Step 2, adding PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid to deionized water to obtain a growth solution, wherein the addition ratio of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid is 10ml:1.5ml:1.5ml:1.5ml:0.8ml:0.8ml, the concentration of PVP solution is 8wt.%, the concentration of AgNO3 is 0.6mM, and the concentration of ascorbic acid is 0.7mM. The NWFs / Au nanofiber membrane obtained in step 1 is placed in the growth solution at 4°C and stirred at a rate of 200 rpm for 40 minutes. After taking it out, it is continued to be placed in the growth solution under certain conditions and stirred. This cycle is repeated for at least 3 times to obtain a non-woven fabric @Au-Ag nanofiber membrane that has been grown for multiple cycles, and then the non-woven fabric @Au-Ag nanofiber membrane is washed with deionized water and dried at room temperature;

[0117] In step 3, the packaging layer, non-woven fabric @Au-Ag nanofiber membrane, and interdigital electrodes are stacked and packaged from top to bottom, wherein both ends of the interdigital electrodes are connected with wires to complete the preparation of the flexible pressure sensor based on the non-woven fabric @Au-Ag nanofiber membrane. The packaging layer is a flexible substrate, which can be a fiber cloth or a soft polymer membrane. The interdigital electrodes are connected to the non-woven fabric @Au-Ag fiber membrane to form a working circuit.

Claims

1. A method for preparing a flexible pressure sensor for detecting nystagmus, characterized in that: The specific implementation steps are as follows: Step 1: soak the non-woven fabric membrane in a chloroauric acid solution, wash the surface with deionized water, soak it in a sodium borohydride solution, and rinse it with deionized water to obtain a NWFs / Au nanofiber membrane; Step 2: PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid are added to deionized water to obtain a growth solution. The NWFs / Au nanofiber membrane obtained in step 1 is placed in the growth solution under certain conditions and stirred, and then washed with deionized water to obtain a non-woven fabric@Au-Ag nanofiber membrane. Step 3: stack the encapsulation layer, non-woven fabric@Au-Ag nanofiber membrane, and interdigital electrodes from top to bottom and encapsulate them, wherein both ends of the interdigital electrodes are connected with wires to complete the preparation of the flexible pressure sensor based on the non-woven fabric@Au-Ag nanofiber membrane; The step 1 of soaking the non-woven membrane in the chloroauric acid solution is specifically as follows: soaking the non-woven membrane in the chloroauric acid solution with a concentration of 0.02-0.03 mM for 1-5 minutes; In step 1, the non-woven fabric membrane is immersed in a chloroauric acid solution, and then the surface is washed with deionized water for at least three cycles, and then immersed in a sodium borohydride solution; The soaking in the sodium borohydride solution in step 1 is specifically as follows: soaking in a sodium borohydride solution with a concentration of 0.02-0.03 mM for 1-5 minutes; The operation of washing the surface with deionized water after soaking in the sodium borohydride solution in step 1 is repeated at least three times to obtain a multi-cycle NWFs / Au nanofiber membrane; In step 2, the addition ratio of deionized water, PVP solution, acetonitrile, ethanol, AgNO3, and ascorbic acid is 10 ml: 1-2 ml: 1-2 ml: 1-2 ml: 0.5-1 ml: 0.5-1 ml; The concentration of the PVP solution added in step 2 is 5-10 wt.%, the concentration of AgNO3 added is 0.1-1 mM, and the concentration of ascorbic acid added in step 2 is 0.1-1 mM; In step 2, the NWFs / Au nanofiber membrane obtained in step 1 is placed in a growth solution under certain conditions and stirred. Specifically, the NWFs / Au nanofiber membrane obtained in step 1 is placed in a growth solution at a temperature of 4-10° C. and stirred at a rate of 200 revolutions per minute for 10-40 minutes. In step 2, the NWFs / Au nanofiber membrane is placed in the growth liquid under certain conditions and stirred. After being taken out, it is placed in the growth liquid again under certain conditions and stirred. This cycle is repeated for at least 3 times to obtain a non-woven fabric @Au-Ag nanofiber membrane that has undergone multiple cycles of growth. The non-woven fabric @Au-Ag nanofiber membrane is then washed with deionized water and dried at room temperature to obtain a NWFs@Ag nanofiber membrane.

2. The method for preparing a flexible pressure sensor for detecting nystagmus according to claim 1, wherein: The encapsulation layer in step 3 is a flexible substrate.

3. A flexible pressure sensor for detecting nystagmus, characterized in that: The flexible pressure sensor for detecting nystagmus according to the preparation method of claim 2 is prepared, comprising a packaging layer, a non-woven fabric @Au-Ag nanofiber membrane, and an interdigital electrode stacked in sequence from top to bottom, the stacked packaging layer, non-woven fabric @Au-Ag nanofiber membrane, and interdigital electrodes are encapsulated and the two ends of the interdigital electrodes are connected to external testing equipment through wires.

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