Brain-computer interaction-oriented ionizing pressure sensor and manufacturing method thereof

Abstract

The invention relates to the technical field of flexible pressure sensors, in particular to a brain-computer interaction-oriented ionizing pressure sensor, which comprises a first flexible substrate layer, a second flexible substrate layer and a capacitor structure formed between the first flexible substrate layer and the second flexible substrate layer, when sensing pressure change, the first flexible substrate layer and the second flexible substrate layer output capacitance signals; the capacitor structure comprises a first metal electrode layer, a second metal electrode layer and a supporting layer which is formed between the first metal electrode layer and the second metal electrode layer and is provided with a steady-state blocking structure. The supporting layer comprises a microporous structure, hydrogel is filled in the microporous structure to form a hydrogel dielectric layer, the hydrogel dielectric layer is in contact with electrode plates of the first metal electrode layer and the second metal electrode layer, and the hydrogel dielectric layer is used as an ion transmission medium. And meanwhile, movable ions are provided for the first metal electrode layer and the second metal electrode layer.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible pressure sensors, and in particular to an ionized pressure sensor for brain-computer interaction and a manufacturing method thereof. Background Art

[0002] Flexible sensors have broad application prospects in the field of brain-computer interfaces. Among them, flexible ion-type sensors usually adopt a "sandwich structure", that is, electrodes on both sides and a colloidal dielectric layer material in the middle. The electrodes on both sides contact the dielectric layer material to form a capacitor, similar to two capacitors in series. When external pressure squeezes the sensor, it causes the dielectric layer between the electrodes to deform, which in turn causes the contact area between the electrodes and the dielectric layer to change, causing the ion distribution in the dielectric layer to change, and thus causing a change in capacitance. The capacitance value is positively correlated with the contact area, and the sensor senses pressure through the change in capacitance.

[0003] The performance of existing flexible ionization sensors is highly dependent on the stability of the dielectric layer. However, this layer is susceptible to factors such as manufacturing, storage, and the sensor's external environment. The external environment can cause changes in the water content of the dielectric layer, while impurities in the external environment can also contaminate the dielectric layer, further weakening its stability.

[0004] Furthermore, changes in the moisture content of the dielectric layer can trigger a series of chain reactions. For example, due to the uneven ion concentration in the dielectric layer, the signal response becomes inconsistent, and the spatial resolution and monitoring accuracy of the sensor are also negatively affected.

[0005] Because the base materials and packaging methods of existing flexible ionization sensors often fail to effectively isolate the sensor's sensitive materials from the external environment, there is an urgent need to develop an ionization pressure sensor for brain-computer interaction that can improve the stability of sensor performance and thus ensure the reliability of brain-computer interaction. Summary of the Invention

[0006] (1) Technical issues to be resolved

[0007] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an ionized pressure sensor for brain-computer interaction and a manufacturing method, which solves the technical problem of insufficient stability of the dielectric layer of the existing ionized pressure sensor.

[0008] (2) Technical solution

[0009] In order to achieve the above objectives, the main technical solutions adopted by the present invention include:

[0010] An ionized pressure sensor for brain-computer interaction includes: a first flexible substrate layer, a second flexible substrate layer, and a capacitor structure formed between the first and second flexible substrate layers. When the first and second flexible substrate layers sense pressure changes, they output a capacitor signal.

[0011] The capacitor structure includes a first metal electrode layer, a second metal electrode layer, and a support layer having a stable blocking structure formed between the first metal electrode layer and the second metal electrode layer;

[0012] The support layer includes a microporous structure, the microporous structure is filled with hydrogel to form a hydrogel dielectric layer, the hydrogel dielectric layer contacts the electrode sheets of the first metal electrode layer and the second metal electrode layer, and the hydrogel dielectric layer is used to simultaneously provide movable ions to the first metal electrode layer and the second metal electrode layer.

[0013] The first metal electrode layer includes a plurality of first electrode sheets formed on the first flexible base layer by deposition, and a first signal transmission structure connecting all the first electrode sheets through a first metal wire;

[0014] The second metal electrode layer includes a plurality of second electrode sheets formed on the second flexible base layer by deposition, and a second signal transmission structure connecting all the second electrode sheets through a second metal wire;

[0015] The first signal transmission structure and the second signal transmission structure are used to transmit the sensed capacitance signal to the connecting wire of the ionization pressure sensor.

[0016] The support layer includes a functional area with multiple microporous structures and a support area without microporous structures;

[0017] The functional area is located between the first metal electrode layer and the second metal electrode layer;

[0018] The support area is located between the first flexible substrate layer and the second flexible substrate layer.

[0019] The top surface and the bottom surface of the functional area respectively form metal wire grooves matching the first metal wire and the second metal wire.

[0020] The ionization type pressure sensor has a rectangular layered structure, and the width of the ionization type pressure sensor is 5-15 mm.

[0021] The shape of the electrode sheet and the microporous structure is circular or square;

[0022] The diameter or width of the electrode sheet and the microporous structure is in the range of 20-200 μm;

[0023] The size of the microporous structure is smaller than or equal to that of the electrode sheet.

[0024] The first flexible base layer and the second flexible base layer are both made of polymer flexible materials, and the polymer flexible materials include polyimide and polyethylene terephthalate.

[0025] A method for manufacturing an ionized pressure sensor for brain-computer interaction, which is applied to the ionized pressure sensor for brain-computer interaction, includes the following manufacturing steps:

[0026] Step 1: Spin-coat a polyimide solution on two clean silicon wafers and solidify the solution to form a flexible base layer.

[0027] Step 2: Spin-coating photoresist on the flexible substrate layer, photolithography of the circuit pattern, and developing after photolithography;

[0028] Step 3: depositing metal electrode sheets and circuits on the two developed flexible substrate layers by magnetron sputtering to form a metal electrode layer;

[0029] Step 4: Select one of the flexible substrate layers on which the metal electrode layer has been formed and coat it with SU-8 photoresist;

[0030] Step 5: Photolithography is performed at the position corresponding to the electrode sheet, and after development, a microporous structure is dug out on the SU-8 film to form a support layer;

[0031] Step 6: injecting hydrogel into the microporous structure to form a hydrogel dielectric layer;

[0032] Step 7: Align the electrode sheet of another flexible substrate layer with the position of the microporous structure and attach it to the hydrogel dielectric layer to form an ionized pressure sensor.

[0033] A method for monitoring brain blood flow velocity, using an ionized pressure sensor for brain-computer interaction, includes the following steps:

[0034] Step 1: Implant the ionized pressure sensor into the brain blood vessels, attaching it to two points A and B selected on the inner wall of the brain blood vessels, with a distance of 3-5 cm between the two points;

[0035] Step 2: The pressure signals P1 and P2 at points A and B are collected by an ionized pressure sensor, and the pressure signals P1 and P2 are transmitted to a receiving device outside the human body.

[0036] Step 3: The receiving device transmits the pressure signals P1 and P2 to the computer, and the computer calculates the blood flow rate based on the received pressure signals. The calculation formula of the blood flow rate is as follows:

[0037]

[0038] Where P1 and P2 are the blood vessel wall pressures (Pa) at points A and B, respectively; v1 and v2 are the blood flow velocities (m / s) at points A and B, respectively; ρ is the blood density, ρ≈1060 kg / m 3 ; g is the acceleration due to gravity, g = 9.81 m / s 2 ; h1 and h2 are the heights of points A and B (m).

[0039] If the blood vessel at the selected measurement location is in a horizontal position, that is, h1 = h2, the blood flow velocity is calculated as:

[0040]

[0041] If the cross-sectional areas of the blood vessels at points A and B are the same, that is, A1≈A2, then the formula for calculating the blood flow rate is:

[0042]

[0043] The blood flow velocity v is obtained by computer calculation;

[0044] If the cross-sectional areas of the blood vessels at points A and B are different, that is, A1≠A2, then according to the continuity equation:

[0045] A1v1=A2v2

[0046] The calculation formula for the blood flow velocity v2 at point B is:

[0047]

[0048] The calculation formula for the blood flow velocity v1 at point A is:

[0049]

[0050] The blood flow velocities v1 and v2 at points A and B are calculated by computer.

[0051] (3) Beneficial effects

[0052] The beneficial effects of the present invention are: the present invention provides an ionized pressure sensor for brain-computer interaction, which has a steady-state blocking structure, including a flexible base layer and a metal electrode layer deposited on the flexible base layer, a support layer with a microporous structure is arranged between the two metal electrode layers, and hydrogel is filled into the microporous structure to form a hydrogel dielectric layer, thereby concentrating the force-bearing area of ​​the hydrogel, which can effectively maintain the stability of the internal environment of the sensor, improve the stability of the dielectric layer, and thus ensure the reliability of brain-computer interaction.

[0053] By setting up a flexible base layer, the stability of the internal environment of the sensor can be maintained. The flexible base layer uses a polymer flexible material with good flexibility, thermal stability and mechanical strength. It can serve as the supporting structure of the entire sensor and can maintain stability under bending or stretching conditions, making the sensor suitable for various extreme environments, including high humidity, high heat or variable mechanical deformation scenarios.

[0054] The metal electrode layer is deposited on the flexible substrate through micro-nano processing technology, making the sensor highly sensitive to external pressure changes and meeting the needs of fine monitoring in complex scenarios.

[0055] The sensor performs pressure sensing based on capacitance changes. It does not require continuous power supply and responds only when the signal changes. It is suitable for low-power application scenarios and can be used to monitor pressure within blood vessels in the human brain.

[0056] The ionized pressure sensor of the present invention achieves comprehensive performance optimization of high sensitivity and high stability through material selection and structural design, providing a more efficient and reliable solution for flexible sensors in the field of brain-computer interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Schematic diagram of the three-dimensional structure of the ionization pressure sensor of the present invention;

[0058] Figure 2 is a top view of the first flexible substrate layer of the present invention;

[0059] Figure 3 is a top view of the first metal electrode layer of the present invention;

[0060] Figure 4 A top view of the support layer of the present invention;

[0061] Figure 5 3D is a perspective view of the hydrogel dielectric layer of the present invention.

[0062] [Description of Reference Numerals]

[0063] 1: First flexible substrate layer; 2: First metal electrode layer; 3: Support layer; 4: Hydrogel dielectric layer; 5: Second metal electrode layer; 6: Second flexible substrate layer; 2-1: First electrode sheet; 2-2: First metal wire; 2-3: First signal transmission structure; 3-1: Support area; 3-2: Microporous structure; 3-3: Metal wire groove. DETAILED DESCRIPTION

[0064] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below with reference to the accompanying drawings and through specific embodiments. Figure 1 The orientation is referenced.

[0065] Hydrogels are water-soluble polymer-based materials, with common examples including polyvinyl alcohol (PVA), polyacrylic acid (PAA), and polyethylene glycol (PEG). They maintain softness and elasticity, and possess advantages such as high sensitivity, excellent flexibility, and good biocompatibility. Hydrogels serve as dielectric layers, typically by dissolving these materials and then adding ions to them. This serves as an ion storage medium to increase capacitance per unit area.

[0066] A hydrogel ionoelectric sensor is a sensor that monitors physical or chemical changes based on the ionic conductivity of hydrogels. The performance of the sensor is highly dependent on the stability of the dielectric layer. However, the dielectric layer is easily affected by factors such as manufacturing, storage, and the external environment of the sensor. A humid or dry external environment may cause changes in the water content in the dielectric layer. At the same time, impurities in the external environment may also contaminate the dielectric layer, further weakening its stability, leading to sensor failure and inaccurate measurements. To this end, the core improvement of this application is how to improve the layer where the hydrogel is located to ensure the stability of the hydrogel dielectric layer 4 in different environments.

[0067] The present invention provides an ionized pressure sensor for brain-computer interaction, comprising a flexible base layer and a metal electrode layer deposited on the flexible base layer, wherein a support layer 3 having a stable locking structure is arranged between the two metal electrode layers, wherein the stable locking structure refers to a sealing structure used to maintain a stable internal environment.

[0068] The support layer 3 includes multiple microporous structures 3-2, which are filled with a hydrogel dielectric layer 4. The microporous structures 3-2 form a stable blockade relative to the hydrogel dielectric layer 4, effectively maintaining a stable internal sensor environment and enhancing the stability of the dielectric material. The hydrogel dielectric layer 4 acts as an ion transport medium and provides mobile ions for the metal electrode layer, forming a capacitive structure with the metal electrode layer 4.

[0069] When the flexible base layer senses changes in external pressure, it squeezes the metal electrode layer, and the electrode sheet of the metal electrode layer squeezes the hydrogel dielectric layer 4, causing the hydrogel dielectric layer 4 to deform, increasing the contact area between the hydrogel dielectric layer 4 and the electrode sheet, thereby changing the capacitance value of the capacitor structure and realizing pressure sensing.

[0070] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0071] See attached Figure 1-5 As shown, an embodiment of the present invention provides an ionotropic pressure sensor for brain-computer interaction, which can be used for brain blood flow monitoring. The sensor comprises a first flexible substrate layer 1, a first metal electrode layer 2, a support layer 3, a second metal electrode layer 5, and a second flexible substrate layer 6, arranged in order from bottom to top. The first flexible substrate layer 1 and the second flexible substrate layer 6 serve as the outer support structure of the ionotropic pressure sensor. They are made of polymer flexible materials, which give the sensor good flexibility while maintaining the stability of the sensor's internal environment. The first metal electrode layer 2 and the second metal electrode layer 5 are formed by deposition on opposite sides of the first flexible substrate layer 1 and the second flexible substrate layer 6, respectively. The support layer 3 includes multiple microporous structures 3-2, which are filled with a hydrogel dielectric layer 4. The two ends of the hydrogel dielectric layer 4 contact the electrode pads of the first metal electrode layer 2 and the second metal electrode layer 5, respectively. The first metal electrode layer 2, the hydrogel dielectric layer 4, and the second metal electrode layer 5 form a capacitive structure. The microporous structures 3-2 can effectively maintain the stability of the internal environment of the sensor and improve the stability of the hydrogel dielectric layer 4.

[0072] See attached Figure 2 As shown, the first flexible substrate layer 1 and the second flexible substrate layer 6 are made of polymer flexible materials, including polyimide (PI) and polyethylene terephthalate (PET). Polymer flexible materials have excellent flexibility, thermal stability, and mechanical strength, and can serve as the overall support structure of the sensor, ensuring the sensor maintains structural stability under bending or stretching conditions. Furthermore, the polymer flexible material has excellent sealing properties. When wrapped around the outside of the metal electrode layer, it can maintain the stability of the internal environment of the sensor, thereby improving the stability of the hydrogel dielectric layer 4.

[0073] See attached Figure 3 As shown, the first metal electrode layer 2 includes a plurality of first electrode sheets 2-1 deposited on the first flexible substrate layer 1 by micro-nano processing technology, and a signal transmission structure 2-3 connected to all the first electrode sheets 2-1 through a first metal wire 2-2. The second metal electrode layer 5 includes a plurality of second electrode sheets deposited on the second flexible substrate layer 6 by micro-nano processing technology, and a second signal transmission structure connected to all the second electrode sheets through a second metal wire. The first signal transmission structure 2-3 of this embodiment adopts a rectangular layered structure, and the first signal transmission structure 2-3 and the second signal transmission structure are both used to transmit the induced capacitance signal to the connecting wire of the ionizing pressure sensor. By setting the signal transmission structure 2-3, it is convenient for the sensor to lead the connecting wire to the outside, transmit the capacitance information to the receiving device, and connect the power supply.

[0074] See attached Figure 4As shown, the support layer 3 includes a functional area provided with multiple microporous structures 3-2 and a support area 3-1 without a microporous structure 3-2, wherein the support area 3-1 is located between the first flexible substrate layer 1 and the second flexible substrate layer 6, and its bottom surface and top surface are respectively adhered to the first flexible substrate layer 1 and the second flexible substrate layer 6, serving as a support structure between the first flexible substrate layer 1 and the second flexible substrate layer 6.

[0075] A plurality of microporous structures 3-2 are provided corresponding to the electrode sheets in the functional area. The microporous structure 3-2 is located between the first metal electrode layer 2 and the second metal electrode layer 5. That is, the first electrode sheet 2-1, the microporous structure 3-2 and the second electrode sheet correspond one to one.

[0076] The size of the microporous structure 3-2 is smaller than or equal to that of the electrode sheet, and the microporous structure 3-2 is filled with a hydrogel dielectric layer 4. Sodium chloride (NaCl), potassium hydroxide (KOH), or sodium acetate (CH3COONa) is added to the hydrogel dielectric layer 4, so that the hydrogel dielectric layer 4 contains a large number of mobile positive and negative ions.

[0077] Because the excess electron carriers on the surfaces of the first metal electrode layer 2 and the second metal electrode layer 5 form strong static electricity that interacts with the ions in the hydrogel dielectric layer 4, the ions are adsorbed to the electrode surface, forming a double layer. Based on this operating principle, the hydrogel dielectric layer 4, the first metal electrode layer 2 and the second metal electrode layer 5 form a supercapacitor based on the double layer effect, realizing the sensing function. By filling the microporous structure 3-2 with hydrogel to form the hydrogel dielectric layer 4, the hydrogel dielectric layer 4 is placed in a tiny closed environment, improving the stability of the dielectric layer.

[0078] In this embodiment, the electrode sheet is circular, and the microporous structure 3-2 is circular. The diameter of the electrode sheet is greater than or equal to that of the microporous structure 3-2, and the width of the electrode sheet and microporous structure 3-2 ranges from 20 to 200 μm. The electrode sheet and microporous structure 3-2 may also be square, or one of them may be circular and the other square. The specific shape and size of the electrode sheet and microporous structure 3-2 can be selected based on actual application requirements.

[0079] The support layer 3 is made of an elastic material and has a certain degree of elasticity. The functional area of ​​the support layer 3 is provided with double-sided metal wire grooves 3-3 corresponding to the metal wires. That is, the top and bottom surfaces of the support layer 3 are provided with metal wire grooves 3-3 corresponding to the first metal wire 2-2 and the second metal wire, respectively, to protect and isolate the metal wires.

[0080] The diameter of human brain blood vessels is typically 3-5 mm and the circumference is 9-15 mm. The ionized pressure sensor for brain-computer interaction provided by the embodiment of the present invention has a width of 5-15 mm and a flexible base layer made of a polymer flexible material. It can conform to human brain blood vessels and can be used for brain blood flow velocity monitoring. The specific monitoring method includes the following steps:

[0081] Step 1: Implant the ionized pressure sensor into the brain blood vessels, attaching it to two points A and B selected on the inner wall of the brain blood vessels, with a distance of 3-5 cm between the two points;

[0082] Step 2: The pressure signals P1 and P2 at points A and B are collected by an ionized pressure sensor, and the pressure signals P1 and P2 are transmitted to a receiving device outside the human body.

[0083] Step 3: The receiving device transmits the pressure signals P1 and P2 to the computer, and the computer calculates the blood flow rate based on the received pressure signals. The calculation formula of the blood flow rate is as follows:

[0084]

[0085] Where, P1 and P2 are the pressures of the inner wall of the blood vessels at points A and B (Pa), v1 and v2 are the blood flow velocities at points A and B (m / s), and ρ is the blood density, ρ≈1060 kg / m 3 ; g is the acceleration due to gravity, g = 9.81 m / s 2 ; h1 and h2 are the heights of points A and B (m).

[0086] If the blood vessel at the selected measurement location is in a horizontal position, that is, h1 = h2, the blood flow velocity is calculated as:

[0087]

[0088] If the cross-sectional areas of the blood vessels at points A and B are the same, that is, A1≈A2, v1=v2=v, then the formula for calculating the blood flow velocity is:

[0089]

[0090] The blood flow velocity v is calculated by computer.

[0091] If the cross-sectional areas of the blood vessels at points A and B are different, that is, A1≠A2, then according to the continuity equation:

[0092] A1v1=A2v2

[0093] The calculation formula for the blood flow velocity v2 at point B is:

[0094]

[0095] The calculation formula for the blood flow velocity v1 at point A is:

[0096]

[0097] The blood flow velocities v1 and v2 at points A and B are calculated by computer.

[0098] Normally, blood vessels in a horizontal position with no significant change in diameter are selected for measurement. That is, under the conditions of h1=h2, A1≈A2, and v1=v2=v, the blood flow velocity is calculated as:

[0099]

[0100] The ionization pressure sensor of the present application can use the above method to quickly measure the blood flow rate in the brain and realize the characterization of human brain activity.

[0101] An embodiment of the present invention further provides a method for manufacturing an ionization pressure sensor, comprising the following steps:

[0102] Step 1: Spin-coat a polyimide solution on two clean silicon wafers and solidify the solution to form a flexible base layer.

[0103] Step 2: Spin-coating photoresist on the flexible substrate layer, photolithography of the circuit pattern, and developing after photolithography;

[0104] Step 3: depositing metal electrode sheets and circuits on the two developed flexible substrate layers by magnetron sputtering to form a metal electrode layer;

[0105] Step 4: Select one of the flexible substrate layers on which the metal electrode layer has been formed and coat it with SU-8 photoresist;

[0106] Step 5: Photolithography is performed at the position corresponding to the electrode sheet, and after development, a microporous structure 3-2 is dug out on the SU-8 film to form a support layer 3;

[0107] Step 6: injecting hydrogel into the microporous structure 3-2 to form a hydrogel dielectric layer 4;

[0108] Step 7: Align the electrode sheet of another flexible substrate layer with the position of the microporous structure 3 - 2 and attach it to the hydrogel dielectric layer 4 to form an ionotropic pressure sensor.

[0109] The ionized pressure sensor provided by the present invention has a support layer 3 having a microporous structure 3-2 arranged between the metal electrode layers, and hydrogel is filled into the microporous structure 3-2 to form a hydrogel dielectric layer 4, which concentrates the force-bearing area of ​​the hydrogel and can effectively maintain the stability of the hydrogel dielectric layer 4, thereby improving the sensitivity and stability of the sensor.

[0110] The flexible base layer is made of a flexible polymer material with good biocompatibility, as well as excellent flexibility, thermal stability, and mechanical strength. It can serve as the supporting structure of the entire sensor and maintain stability under bending or stretching conditions. At the same time, it can also maintain a stable internal environment of the sensor.

[0111] By combining flexible structures with highly durable materials, the sensor is suitable for various extreme environments, including high humidity, high heat, or variable mechanical deformation scenarios.

[0112] The metal electrode layer adopts micro-nano processing technology, which makes the sensor highly sensitive and can meet the needs of fine monitoring in complex scenes.

[0113] The sensor performs pressure sensing based on the capacitance change of the hydrogel dielectric layer 4. It does not require continuous power supply and only responds when the signal changes. It is suitable for low-power application scenarios.

[0114] The ionized pressure sensor of the present invention achieves comprehensive performance optimization of high sensitivity and high stability through material selection and structural design, providing a more efficient and reliable solution for flexible sensors in the field of brain-computer interface.

[0115] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0116] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0117] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0118] In the description of this specification, the terms "one embodiment", "some embodiments", "embodiments", "examples", "specific examples" or "some examples" refer to the specific features, structures, materials or characteristics described in conjunction with the embodiment or example and included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0119] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An ionization pressure sensor for brain-computer interaction, characterized in that: include: A first flexible base layer (1), a second flexible base layer (6), and a capacitor structure formed between the first flexible base layer (1) and the second flexible base layer (6), wherein the first flexible base layer (1) and the second flexible base layer (6) output a capacitor signal when sensing a pressure change; The capacitor structure comprises a first metal electrode layer (2), a second metal electrode layer (5), and a support layer (3) having a stable blocking structure formed between the first metal electrode layer (2) and the second metal electrode layer (5); The support layer (3) comprises a microporous structure (3-2), the microporous structure (3-2) is filled with hydrogel to form a hydrogel dielectric layer (4), the hydrogel dielectric layer (4) contacts the electrode sheets of the first metal electrode layer (2) and the second metal electrode layer (5), and the hydrogel dielectric layer (4) is used to simultaneously provide movable ions for the first metal electrode layer (2) and the second metal electrode layer (5).

2. The ionized pressure sensor for brain-computer interaction according to claim 1, characterized in that: The first metal electrode layer (2) comprises a plurality of first electrode sheets (2-1) formed on the first flexible base layer (1) by deposition, and a first signal transmission structure (2-3) connecting all the first electrode sheets (2-1) via a first metal wire (2-2); The second metal electrode layer (5) comprises a plurality of second electrode sheets formed on the second flexible base layer (6) by deposition, and a second signal transmission structure connecting all the second electrode sheets via a second metal wire; The first signal transmission structure (2-3) and the second signal transmission structure are used to transmit the sensed capacitance signal to the connecting wire of the ionization pressure sensor.

3. The ionized pressure sensor for brain-computer interaction according to claim 2, characterized in that: The support layer (3) comprises a functional area provided with a plurality of microporous structures (3-2) and a support area (3-1) not provided with the microporous structure (3-2); The functional area is located between the first metal electrode layer (2) and the second metal electrode layer (5); The support area (3-1) is located between the first flexible base layer (1) and the second flexible base layer (6).

4. The ionized pressure sensor for brain-computer interaction according to claim 3, characterized in that: The top surface and the bottom surface of the functional area respectively form metal wire grooves (3-3) that match the first metal wire (2-2) and the second metal wire.

5. The ionized pressure sensor for brain-computer interaction according to claim 4, characterized in that: The ionization type pressure sensor has a rectangular layered structure, and the width of the ionization type pressure sensor is 5-15 mm.

6. The ionized pressure sensor for brain-computer interaction according to claim 5, characterized in that: The shape of the electrode sheet and the microporous structure (3-2) is circular or square; The diameter or width of the electrode sheet and the microporous structure (3-2) is in the range of 20-200 μm; The size of the microporous structure (3-2) is smaller than or equal to that of the electrode sheet.

7. The ionized pressure sensor for brain-computer interaction according to claim 1, characterized in that: The first flexible base layer (1) and the second flexible base layer (6) are both made of polymer flexible materials, and the polymer flexible materials include polyimide and polyethylene terephthalate.

8. A method for manufacturing an ionized pressure sensor for brain-computer interaction, characterized in that: The ionized pressure sensor for brain-computer interaction according to any one of claims 1 to 7 comprises the following manufacturing steps: Step 1: Spin-coat a polyimide solution on two clean silicon wafers and solidify the solution to form a flexible base layer. Step 2: Spin-coating photoresist on the flexible substrate layer, photolithography of the circuit pattern, and developing after photolithography; Step 3: depositing metal electrode sheets and circuits on the two developed flexible substrate layers by magnetron sputtering to form a metal electrode layer; Step 4: Select one of the flexible substrate layers on which the metal electrode layer has been formed and coat it with SU-8 photoresist; Step 5: Photolithography is performed at the position corresponding to the electrode sheet, and after development, a microporous structure (3-2) is dug out on the SU-8 film to form a support layer (3); Step 6: injecting hydrogel into the microporous structure (3-2) to form a hydrogel dielectric layer (4); Step 7: Align the electrode sheet of another flexible substrate layer with the position of the microporous structure (3-2), and adhere it to the hydrogel dielectric layer (4) to form an ion-type pressure sensor.

9. A method for monitoring brain blood flow velocity, characterized in that: The ion-type pressure sensor for brain-computer interaction according to any one of claims 1 to 7 is used, comprising the following steps: Step 1: Implant the ionized pressure sensor into the brain blood vessels, attaching it to two points A and B selected on the inner wall of the brain blood vessels, with a distance of 3-5 cm between the two points; Step 2: The pressure signals P1 and P2 at points A and B are collected by an ionized pressure sensor, and the pressure signals P1 and P2 are transmitted to a receiving device outside the human body. Step 3: The receiving device transmits the pressure signals P1 and P2 to the computer, and the computer calculates the blood flow rate based on the received pressure signals. The calculation formula of the blood flow rate is as follows: Where P1 and P2 are the blood vessel wall pressures (Pa) at points A and B, respectively; v1 and v2 are the blood flow velocities (m / s) at points A and B, respectively; ρ is the blood density, ρ≈1060 kg / m 3 ; g is the acceleration due to gravity, g = 9.81 m / s 2 ; h1 and h2 are the heights of points A and B (m).

10. The method for monitoring cerebral blood flow velocity according to claim 9, characterized in that: If the blood vessel at the selected measurement location is in a horizontal position, that is, h1 = h2, the blood flow velocity is calculated as: If the cross-sectional areas of the blood vessels at points A and B are the same, that is, A1≈A2, then the formula for calculating the blood flow rate is: The blood flow velocity v is obtained by computer calculation; If the cross-sectional areas of the blood vessels at points A and B are different, that is, A1≠A2, then according to the continuity equation: A1v1=A2v2 The calculation formula for the blood flow velocity v2 at point B is: The calculation formula for the blood flow velocity v1 at point A is: The blood flow velocities v1 and v2 at points A and B are calculated by computer.

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