An electrical signal acquisition electrode and an acquisition method

Abstract

The present application proposes an electrical signal acquisition electrode and acquisition method, which relate to the field of electrical signal acquisition technology. An electrical signal acquisition electrode includes a tube body and a liquid storage cavity provided in the tube body. Both ends of the liquid storage cavity are connected to the outside world. The liquid storage cavity includes an inlet end and an outlet end. The port of the outlet end is provided with an oleophilic and hydrophilic layer and an oleophobic layer. The oleophilic and hydrophilic layer is provided on the outside of the oleophobic layer. The electrode uses a multiphase fluid liquid bridge to collect electrical signals on the chip surface. The electrode and the chip surface are not in direct contact and will not cause damage to the chip surface. The acquisition method can enable the above-mentioned electrode to quickly form a multiphase fluid liquid bridge, which is convenient for the stable acquisition of electrical signals on the chip surface. The acquired signal error is small, the operation is simple, and the practicability is strong.

Description

Technical Field

[0001] The present application relates to the technical field of electrical signal acquisition, and in particular to an electrical signal acquisition electrode and an acquisition method. Background Art

[0002] The detection of electrical signals is an indispensable part of modern industry, especially the precision electronics industry. The most common method of electrical signal testing is to use a voltmeter or ammeter. The test electrodes of existing measuring equipment are mostly made of conductive metal, which inevitably has the following disadvantages:

[0003] 1) Due to the use of metal materials, the mechanical compatibility with the test chip is poor, which can easily scratch the chip surface, especially the surface of the precision chip;

[0004] 2) Metal materials have a certain degree of rigidity and cannot be well fixed on the test chip without movement, and cannot ensure close electrical contact with the test chip;

[0005] 3) The size of the metal material is fixed, and its compatibility with electrodes of different sizes or even different numbers of electrodes is poor. Summary of the Invention

[0006] The purpose of the present application is to provide an electrical signal collection electrode, which uses a multiphase fluid liquid bridge to collect electrical signals on the chip surface, and the electrode does not directly contact the chip and will not cause mechanical damage.

[0007] Another object of the present application is to provide a collection method that is simple to operate and can reduce the interference of electrical signals caused by the external environment, so that the collected electrical signals are more accurate.

[0008] The embodiment of the present application is implemented as follows:

[0009] In a first aspect, an embodiment of the present application provides an electrical signal acquisition electrode, which includes a tube body and a liquid storage cavity arranged in the above-mentioned tube body, both ends of the above-mentioned liquid storage cavity are connected to the outside, the above-mentioned liquid storage cavity includes an inlet end and an outlet end, and the port of the above-mentioned outlet end is provided with an oleophilic and hydrophilic layer and an oleophobic layer, and the above-mentioned oleophilic and hydrophilic layers are arranged on the outside of the above-mentioned oleophobic layer.

[0010] In some embodiments of the present application, the liquid storage chamber includes a first liquid storage unit and a second liquid storage unit, the first liquid storage unit and the second liquid storage unit are coaxially connected, the first liquid storage unit is arranged on the side close to the inlet end, and the second liquid storage unit is arranged on the side close to the outlet end.

[0011] In some embodiments of the present application, the first liquid storage unit and the second liquid storage unit are both cylindrical.

[0012] In some embodiments of the present application, the inner diameter of the first liquid storage unit is greater than the inner diameter of the second liquid storage unit.

[0013] In some embodiments of the present application, the oleophobic layer is disposed on the inner side of the port of the outlet and close to the circumference of the outlet, and the oleophilic and hydrophilic layers are disposed on the outer circumference of the oleophobic layer.

[0014] In some embodiments of the present application, the tube body is made of 3D printing material.

[0015] In a second aspect, an embodiment of the present application provides a method for collecting electrical signals based on the above-mentioned electrical signal collection electrode, comprising the following steps:

[0016] Absorption of multiphase fluid: A sampler is used to extract the aqueous conductive liquid and the oil phase liquid, and introduce them into the liquid storage chamber to form a multiphase liquid bridge;

[0017] Signal acquisition: Then the electrical signal is collected.

[0018] In some embodiments of the present application, in the above-mentioned multiphase fluid extraction step, the aqueous conductive liquid is extracted first and then the oily liquid is extracted, and the aqueous conductive liquid and the oily liquid are stored in the sampler at the same time.

[0019] In some embodiments of the present application, the collection method further includes processing the tube body, and the processing includes:

[0020] 3D printing the above-mentioned tube structure;

[0021] Treating the inner channel of the outlet and the circumference of the outlet with a hydrophilic and oleophobic material to form the oleophobic layer;

[0022] The outer circumference of the outlet end is treated with hydrophilic and oleophilic materials to form the oleophilic and hydrophilic layer, which wraps the oleophobic layer.

[0023] In some embodiments of the present application, the above-mentioned collection method also includes fixing the tube body, and the above-mentioned fixing includes: fixing the test chip, fixing the processed tube body above the above-mentioned test chip, and the above-mentioned tube body and the above-mentioned test chip do not contact each other.

[0024] Compared with the prior art, the embodiments of the present application have at least the following advantages or beneficial effects:

[0025] 1. The electrode uses a multiphase fluid bridge to collect bioelectric signals. The electrode and the test chip are not in direct contact, so no mechanical damage will occur. It has partial adaptability to the micro-displacement generated during the test. The viscosity of the droplets can relatively stably connect the upper and lower interfaces to ensure the stability of electrical signal acquisition.

[0026] 2. Since the size of the bottom liquid bridge contact surface can be controlled by the injection volume according to demand, it has better adaptability to large and small electrodes or multiple electrodes on various chips.

[0027] 3. During signal collection, since the oil phase can isolate the external environment, it can reduce the interference of electrical signals caused by the external environment, making the collected electrical signals more accurate.

[0028] 4. The present application provides a collection method, which can enable the above-mentioned electrodes to quickly form a multiphase fluid bridge, facilitate the stable collection of electrical signals on the chip surface, and the collected signal has small error, simple operation and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 This is a structural diagram of an electrical signal collection electrode in Example 1 of the present application;

[0031] Figure 2 This is a top view of an electrical signal collection electrode in Example 1 of the present application;

[0032] Figure 3 This is a basic principle diagram of the liquid bridge connecting the upper and lower interfaces in Example 1 of this application;

[0033] Figure 4a This is a schematic diagram of the liquid bridge in Example 1 of the present application being able to adapt to chip electrode surfaces of different shapes;

[0034] Figure 4b This is a schematic diagram of the liquid bridge in Example 1 of this application being able to flexibly and adaptively deform as the upper and lower interfaces slightly move. Figure 1 ;

[0035] Figure 4c This is a schematic diagram of the liquid bridge in Example 1 of this application being able to flexibly and adaptively deform as the upper and lower interfaces slightly move. Figure 2 ;

[0036] Figure 5 A schematic diagram for collecting electrical signals from a single or multiple electrodes;

[0037] Figure 6 This is a comparison of the signals at 20mV and 5mV collected using a multiphase liquid bridge during signal acquisition in Example 1 of the present application;

[0038] Figure 7 Schematic diagram of the process of forming a multiphase fluid bridge on the surface of the test chip in Example 2 of the present application;

[0039] Figure 8 This is a simulation result diagram of the multiphase flow bridge formation process in Example 2 of the present application;

[0040] Figure 9 This is a schematic diagram of fixing the tube body on the test chip in Example 2 of the present application;

[0041] Figure 10 Schematic diagram of the formation principle of the multiphase fluid liquid bridge structure in Example 2 of the present application;

[0042] Figure 11 This is a flow chart of the collection method in Example 2 of the present application.

[0043] Icon: 1-tube body; 2-first liquid storage unit; 3-second liquid storage unit; 4-oleophobic layer; 5-lipophilic and hydrophilic layer; 6-chip; 11-electrode area; 12-area to be modulated; 21-aqueous phase area. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without making any creative efforts shall fall within the scope of protection of the present application.

[0046] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0047] In the description of the embodiments of this application, it should be noted that if the terms "upper", "lower", "inner", "outer", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting this application. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0048] In the description of the embodiments of this application, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in this application based on specific circumstances.

[0049] Example 1

[0050] Please refer to Figures 1-6 This embodiment provides an electrical signal acquisition electrode, which includes a tube body 1 and a liquid storage cavity arranged in the tube body 1. Both ends of the liquid storage cavity are connected to the outside. The liquid storage cavity includes an inlet end and an outlet end. The port of the outlet end is provided with an oleophilic and hydrophilic layer 5 and an oleophobic layer 4. The oleophilic and hydrophilic layer 5 is arranged on the outside of the oleophobic layer 4.

[0051] like Figure 1 As shown, the electrode adopts a multiphase fluid liquid bridge structure to realize the flexible connection between the electrode and the test chip 6. The liquid storage cavity inside the tube body 1 is a wedge-shaped "hanging drop structure", and the liquid column in the tube body 1 will produce a stable hydraulic pressure difference on the oil phase below, thereby forcing the aqueous phase solution into the oil phase to form a liquid bridge structure. An underwater oleophobic layer 4 (with a hydrophilic and oleophobic effect, which can block the oil phase but not the water phase) and an oleophilic and hydrophilic layer 5 are provided at the bottom of the tube body 1. The oleophobic layer 4 is wrapped by the oleophilic and hydrophilic layer 5. Since oil and water are incompatible with each other, an oil-in-water multiphase liquid bridge structure can be formed. When collecting electrical signals on the surface of the chip 6, the test chip 6 is arranged below the electrode. The tube body 1 and the test chip 6 are not in direct contact, and are connected in the middle by an oil-in-water multiphase liquid bridge structure. This structure can transfer charges through the ionic solution in the middle to realize the collection of electrical signals. When the liquid bridge is formed, due to the surface tension of the liquid bridge, the liquid bridge can use the viscosity of the liquid droplets to stably connect the tube body 1 and the test chip 6, thereby ensuring the stability of electrical signal acquisition. Figure 3As shown, the surface tension of the gas-liquid interface provides an upward adhesion force, thereby playing the role of bonding the upper and lower interfaces (the bottom of the tube body 1 and the interface of the test chip 6). Therefore, the upper and lower interfaces must have hydrophilic properties. Because it uses a fluid liquid bridge, it has partial adaptability to displacement: 1. Figure 4a As shown in Figure 1, the liquid bridge can adapt to chip electrode surfaces of different shapes and has good adaptability to complex chips, especially 3D chips. 2. The liquid bridge can flexibly and adaptively deform with the micro-motion of the upper and lower interfaces. The deformation diagram is shown in Figure 1. Figure 4b and Figure 4c As shown, even if the distance between the tube body 1 and the surface of the test chip 6 is slightly displaced (including up and down and left and right) when the test chip 6 moves, the liquid bridge in the fluid state can adapt to this unstable change and maintain the stability of charge transfer.

[0052] The purpose of simultaneous detection of multiple electrodes can be achieved by using a multi-phase fluid bridge to realize electrical signal modulation. Since the metal material used in traditional detection electrodes is fixed in size, it is not compatible with chip signal detection of different sizes or even different numbers of electrodes. Figure 5 As shown, by using a multiphase fluid liquid bridge, by adjusting the amount of injected water phase or controlling the distance between the upper end tube and the surface of the chip 6, the contact area between the water phase and the electrode on the surface of the chip 6 and the number of contacting electrodes can be achieved, thereby flexibly realizing the selection of the test electrode or the electrode test part.

[0053] It should be noted that in the oil-in-water structure, the outer "oil" is an oily liquid, which is not limited in this application. The water in the middle is an ionized aqueous solution with conductivity, including physiological saline, etc., which is not limited in this application.

[0054] In this embodiment, the liquid storage chamber includes a first liquid storage unit 2 and a second liquid storage unit 3, the first liquid storage unit 2 and the second liquid storage unit 3 are coaxially connected, the first liquid storage unit 2 is arranged on the side close to the inlet end, and the second liquid storage unit 3 is arranged on the side close to the outlet end.

[0055] like Figure 1 As shown, the first liquid storage unit 2 is located above the second liquid storage unit 3, and the first liquid storage unit 2 is coaxially connected to the second liquid storage unit 3 to form a wedge-shaped "hanging drop structure". When in use, the oil phase and the water phase are injected into the liquid storage cavity from the inlet end of the liquid storage cavity. The oil phase and the water phase pass through the first liquid storage unit 2 and are located in the second liquid storage unit 3 to reach the bottom of the tube body 1. The oil phase and the water phase form a fluid liquid bridge between the bottom of the tube body 1 and the test chip 6, and then electrical stimulation and collection of electrical signals on the surface of the chip 6 are performed. When the oil phase and the water phase flow to the surface of the test chip 6, a certain liquid column height will be formed, generating a stable hydraulic pressure difference, causing the water phase below to enter the oil phase and form a stable liquid bridge.

[0056] In this embodiment, the first liquid storage unit 2 and the second liquid storage unit 3 are both cylindrical.

[0057] The first liquid storage unit 2 and the second liquid storage unit 3 are designed to be cylindrical, so that the flow of liquid in the liquid storage cavity is uniform, which is conducive to more stable transmission of electrical signals.

[0058] In this embodiment, the inner diameter of the first liquid storage unit 2 is greater than the inner diameter of the second liquid storage unit 3 .

[0059] The inner diameter of the first liquid storage unit 2 is larger than that of the second liquid storage unit 3, so that a "hanging drop structure" with a larger upper portion and a smaller lower portion can be formed. The first liquid storage unit 2 is located at the outlet end, and its larger inner diameter is also conducive to the injection of liquid and the control of the height of the liquid column.

[0060] In this embodiment, the oleophobic layer 4 is disposed on the inner side of the port of the outlet and close to the circumference of the outlet, and the oleophilic and hydrophilic layer 5 is disposed on the outer circumference of the oleophobic layer 4 .

[0061] like Figure 1 As shown, the bottom of the tube body 1 is provided with an underwater oleophobic layer 4, which has a hydrophilic and oleophobic effect, blocking the oil phase but not the water phase. The oleophobic layer 4 is circular and is positioned at the outlet port of the liquid storage chamber and in the liquid storage chamber channel near the port. This creates an oleophobic and hydrophilic bottom surface, preventing oil droplets from flowing back into the tube body 1. An oleophilic and hydrophilic layer 5 is also provided on the outer circumference of the oleophobic layer 4. This coating is applied to the outer circumference of the oleophobic layer 4 using a hydrophilic and oleophobic material, thereby enveloping the oleophobic layer 4. Because oil and water are incompatible, this creates an oil-in-water multiphase liquid bridge structure.

[0062] When collecting electrical signals from the chip 6 surface, the test chip 6 is placed below the electrode. The tube body 1 and the test chip 6 are not in direct contact, but are connected by a multiphase liquid bridge structure of oil-in-water. Since the oil phase can isolate the external environment, the interference of the electrical signals caused by the external environment is reduced, making the collected electrical signals of the test chip 6 more accurate. Figure 6 As shown, the left figure is the collected signal at 20mV, and the right figure is the collected signal at 5mV. The signals at 20mV and 5mV collected by the multiphase fluid liquid bridge provided by the present application have an acquisition error of less than 1mV, which is better than the acquisition error when the oil phase is not used (generally above 5mV).

[0063] In this embodiment, the tube body 1 is made of 3D printing material (silicone material).

[0064] The tube body 1 is made of 3D printing materials, such as silicone.

[0065] Example 2

[0066] Please refer to Figure 7-11 This embodiment provides a collection method for the electrode in embodiment 1, comprising the following steps:

[0067] Absorption of multiphase fluid S300: using a sampler to extract the aqueous conductive liquid and the oil phase liquid, and introducing them into the liquid storage chamber to form a multiphase liquid bridge;

[0068] Signal acquisition: Then the electrical signal is collected.

[0069] This acquisition method is simple to operate and highly practical. It is used for acquiring electrical signals from the electrodes in Example 1. By using this acquisition method, the electrodes can quickly form a multiphase fluid bridge, stably acquire electrical signals from the surface of the chip 6, and have a small error in the acquired signals.

[0070] In this embodiment, in the step of drawing the multiphase fluid, the aqueous conductive liquid is drawn first and then the oily liquid is drawn, and the aqueous conductive liquid and the oily liquid are stored in the sampler at the same time.

[0071] Use a micro syringe to extract the water phase conductive liquid first and then the oil phase liquid, and temporarily retain these two liquids in the micro syringe, so that the order of the squeezed liquids is oil phase first and then water phase. Figure 7 As shown in A and B in FIG, when the oil phase in the microsyringe is first injected into the surface of the test chip 6, an oil phase liquid bridge will be formed between the bottom end of the tube 1 and the test chip 6; Figure 7 As shown in B and C in the figure, when the oil phase liquid is injected, the water phase conductive liquid is injected again. The water phase conductive liquid will form a new liquid bridge containing conductive liquid in the middle of the oil phase liquid bridge, and it will continue to expand as the amount of water phase conductive liquid injected increases, forming a charge path.

[0072] Furthermore, based on COMSOL simulation software, the formation process of the entire multiphase liquid bridge was simulated accordingly. The simulation results are as follows: Figure 8 shown. Figure 8 The light-colored part is the oil phase, and the dark-colored part is the water phase. Figure 8 a in the figure is the initial state, and oil and water have not been injected. As the oil and water are injected, an oily liquid bridge gradually forms in the structure below, such as Figure 8 As shown in b; after the oil phase is injected, with the inflow of the conductive liquid, an oil-water phase liquid bridge is gradually formed, as shown in Figure 8 The above results show that the simulation is completely consistent with the above analysis results. The resistance value is measured and found to be 9Ω, which fully meets the requirements for electrical signal acquisition.

[0073] In this embodiment, the above-mentioned collection method further includes processing the tube body S100, and the processing includes:

[0074] 3D printed tube 1 structure;

[0075] The inner channel of the outlet end and the circumference of the outlet end are treated with a hydrophilic and oleophobic material to form an oleophobic layer 4;

[0076] The outer circumference of the outlet end is treated with hydrophilic and oleophilic materials to form an oleophilic and hydrophilic layer 5 , which wraps the oleophobic layer 4 .

[0077] The bottom and internal channels of the liquid storage chamber are treated with hydrophilic and oleophobic materials to form an underwater oleophobic layer 4, which prevents the oil phase from flowing back into the tube body 1. The outer ring of the bottom of the tube body 1 is then treated with hydrophilic and oleophobic materials to form an oleophilic and hydrophilic layer 5. This layer 5 encapsulates the oleophobic layer 4. As liquid flows out of the liquid storage chamber, a water-in-oil structure forms between the bottom of the tube body 1 and the test chip 6, forming a multiphase fluid bridge that facilitates the acquisition of electrical signals from the surface of the chip 6.

[0078] In this embodiment, the sampling method further includes fixing the tube body S200 , which includes: sampling the test chip 6 , fixing the processed tube body 1 above the test chip 6 , and the tube body 1 and the test chip 6 not contacting each other.

[0079] like Figure 9 As shown, after sampling the test chip 6, the processed tube body 1 is fixed on the top of the test chip 6. At this time, the tube body 1 and the test chip 6 do not contact each other, so the electrode and the test chip 6 are not in direct contact and no mechanical damage will occur.

[0080] In summary, if Figure 11 As shown, the entire process of the above acquisition method includes the following steps:

[0081] Processing of the tube body S100: 1. 3D printing of the tube body 1 structure. In this application, the specific parameters of the tube body 1 are as follows: the inner diameter of the lower part of the tube body 1 is 0.3 mm, the outer diameter is 0.8 mm, and the length is 5 mm (part of the second liquid storage unit); the inner diameter of the upper part of the tube body 1 is 0.6 mm, the outer diameter is 0.8 mm, and the length is 8 mm (part of the first liquid storage unit); 2. The inner channel of the outlet end and the circumferential part of the outlet end are treated with hydrophilic and oleophobic materials to form an oleophobic layer 4; 3. The outer circumferential part of the outlet end is treated with hydrophilic and oleophobic materials to form an oleophilic and hydrophilic layer 5, and the oleophilic and hydrophilic layer 5 wraps the oleophobic layer 4.

[0082] It should be noted here that the parameters of the tube body 1 can also be other values, as long as they can form a multiphase fluid liquid bridge structure (hanging drop structure), and this application does not limit this.

[0083] Fixing of the tube body S200: After sampling the test chip 6, the processed tube body 1 is fixed above the test chip 6. At this time, the tube body 1 and the test chip 6 do not contact each other.

[0084] Absorption of multiphase fluid S300: Use a micro syringe (Gao Pigeon microinjector, 10μl, pointed tip, needle tip outer diameter 0.5mm) to first extract 6μl of aqueous conductive liquid and then extract 2μl of oil phase liquid, and temporarily retain these two liquids in the micro syringe.

[0085] Release of the multiphase liquid bridge on the surface of the test chip 6 S400: After obtaining the oil phase and water phase liquids respectively through the micro-syringe, the needle tip is inserted into the tube body 1, and the oil and water in the micro-syringe are slowly injected into the tube body 1, and then injected onto the test chip to form a liquid bridge.

[0086] Collecting electrical signals and applying electrical stimulation S500: placing the electrical signal collector at the front needle tip of the micro-injector, performing electrical stimulation, and transmitting signals through the signal sensor to complete the collection of electrical signals on the surface of the chip 6.

[0087] It should be noted that the use of a microsyringe is only one embodiment of this application; other syringes or samplers may also be used, and this application is not limited to this. The amount of aqueous conductive liquid and oil phase liquid extracted depends on the specific size of the tube. The above extraction amount is only one embodiment of this application and is not limited to this.

[0088] The principle of the formation of the electrode multiphase fluid liquid bridge structure is:

[0089] 1. Such as Figure 10 As shown in the figure, using the "hanging drop structure", the liquid column in the tube body 1 will generate a stable hydraulic pressure difference on the oil phase below (P3 is the downward pressure generated by gravity, P3 = ρgh, where ρ is the liquid density in the liquid column, g is the gravity constant, and h is the height of the liquid column), thereby forcing the aqueous solution into the oil phase to form a liquid bridge structure. Combined with the Laplace equation, the total downward pressure P0 is:

[0090] P0=P3+P2=ρgh+γ / R (1)

[0091] Where: γ is the surface tension coefficient of the liquid, R is the radius of curvature of the upper liquid column, and P3 is the downward pressure generated by the surface tension.

[0092] From the geometric relationship, we know that R = L / (2cosα), so R is mainly affected by the hydrophilicity of the silicone tube (expressed as the contact angle α) and the upper tube diameter L. From equation (1), we can see that as the liquid column enters the oil phase below, the height of the liquid column decreases, P3 becomes smaller, the value of R is relatively large and basically remains unchanged, so P0 becomes smaller;

[0093] 2. When the water phase enters the oil phase below, due to the mutual incompatibility of oil and water, an oil-in-water structure is formed between the silicone tube and the test chip 6. In this liquid bridge structure, an upward Laplace surface tension is generated (and is mainly affected by it). The total upward pressure is:

[0094] P1=γ1 / R1 (2)

[0095] Where: γ1 is the surface tension coefficient of the oil-water phase, and R1 is the curvature radius of the lower liquid bridge.

[0096] From the geometric relationship, we know that R1 = S / (2cosβ), so R1 is mainly affected by the hydrophilicity of the bottom surface of the silicone tube (expressed as contact angle β) and the distance S between the silicone tube and the surface of the test chip 6. As the liquid column enters the oil phase below, because R1 remains essentially unchanged, P1 also remains essentially unchanged.

[0097] 3. As P0 decreases and P1 remains unchanged, the two eventually reach a force balance, making P0 = P1, and the overall structure enters a stable state, ensuring the stability of the multiphase liquid bridge electrical signal acquisition.

[0098] In summary, the embodiments of the present application provide an electrical signal acquisition electrode and an acquisition method, wherein the acquisition electrode comprises a tube body 1 and a liquid storage cavity provided in the tube body 1, both ends of the liquid storage cavity are connected to the outside, the liquid storage cavity comprises an inlet end and an outlet end, an oleophilic and hydrophilic layer 5 and an oleophobic layer 4 are provided at the port of the outlet end, and the oleophilic and hydrophilic layer 5 is provided on the outside of the oleophobic layer 4. The electrode adopts a multiphase fluid liquid bridge structure to achieve a flexible connection between the electrode and the test chip 6. The liquid storage cavity inside the tube body 1 is a wedge-shaped "hanging drop structure", and the liquid column in the tube body 1 will produce a stable hydraulic pressure difference on the oil phase below, thereby forcing the aqueous phase solution into the oil phase to form a liquid bridge structure. An underwater oleophobic layer 4 is provided at the bottom of the tube body 1, which has a hydrophilic and oleophobic effect and can block the oil phase but not the aqueous phase. The oleophobic layer 4 is circular and is arranged at the port at the outlet end of the liquid storage cavity and at the liquid storage cavity channel near the port, so that the bottom surface of the liquid storage cavity is oleophobic and hydrophilic, preventing oil droplets from flowing back into the tube body 1. An oleophilic and hydrophilic layer 5 is also provided at the outer circumference of the oleophobic layer 4, that is, a hydrophilic and oleophilic material is applied as a coating to the outer circumference of the oleophobic layer 4, thereby wrapping the oleophobic layer 4; since oil and water are incompatible with each other, a multiphase liquid bridge structure of oil-in-water can be formed. When collecting electrical signals on the surface of the chip 6, the test chip 6 is arranged below the electrode, and the tube body 1 and the test chip 6 are not in direct contact. The middle is connected by a multiphase liquid bridge structure of oil-in-water. This structure can transfer charges through the ionic solution in the middle to realize the collection of electrical signals or the application of electrical stimulation. When the liquid bridge is formed, due to the surface tension of the liquid bridge, the liquid bridge can use the viscosity of the droplets to stably connect the tube body 1 and the test chip 6, thereby ensuring the stability of electrical signal collection and electrical stimulation. Because a fluid liquid bridge is used, it has partial adaptability to displacement. The liquid bridge can flexibly and adaptively deform as the upper and lower interfaces slightly move. In this way, even if the distance between the tube body 1 and the test chip 6 surface is slightly displaced when the test chip 6 moves, the liquid bridge in the fluid state can adapt to this unstable change and maintain the stability of charge transfer. The use of a multiphase fluid liquid bridge to achieve electrical signal modulation is to transfer the electron ion charge conversion that originally occurred on the surface of the test chip 6 to the electrode inside the pipeline. Since both ends of the liquid storage cavity are connected to the outside world, the large area and openness of the electrode in the tube body 1 greatly improve its ion injection capability. At the same time, its electrode impedance is relatively small due to the larger electrode area. In addition, moving the electron ion charge conversion to the tube body 1 is also beneficial to reduce the damage to the test chip 6 caused by the interface reaction and improve the compatibility of the electrode.

[0099] This acquisition method can enable the electrodes to quickly form a multiphase fluid bridge, facilitating stable acquisition of electrical signals on the surface of the chip 6 , and the acquired signal error is small, the operation is simple, and the practicability is strong.

[0100] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An electrical signal collection electrode, characterized in that: The invention comprises a tube body and a liquid storage cavity provided in the tube body, wherein both ends of the liquid storage cavity are connected to the outside, the liquid storage cavity comprises an inlet end and an outlet end, and an oleophilic and hydrophilic layer and an oleophobic layer are provided at the port of the outlet end, and the oleophilic and hydrophilic layer is provided on the outside of the oleophobic layer; The liquid storage chamber includes a first liquid storage unit and a second liquid storage unit, the first liquid storage unit and the second liquid storage unit are coaxially connected, the first liquid storage unit is arranged on a side close to the inlet end, and the second liquid storage unit is arranged on a side close to the outlet end; The first liquid storage unit and the second liquid storage unit are both cylindrical; The inner diameter of the first liquid storage unit is greater than the inner diameter of the second liquid storage unit; The oleophobic layer is arranged on the inner side of the port of the outlet end and close to the circumference of the outlet end, and the oleophilic and hydrophilic layers are arranged on the outer circumference of the oleophobic layer.

2. A method for collecting electrical signals based on the electrical signal collecting electrode according to claim 1, characterized in that: The following steps are involved: Absorption of multiphase fluid: A sampler is used to extract water phase and oil phase liquids and introduce them into the liquid storage chamber to form a multiphase liquid bridge; Signal acquisition: Then the electrical signal is collected.

3. A collection method according to claim 2, characterized in that: In the multiphase fluid extraction step, the aqueous conductive liquid is extracted first and then the oil phase liquid is extracted, and the aqueous conductive liquid and the oil phase liquid are stored in the sampler at the same time.

4. A collection method according to claim 2, characterized in that: It also includes processing of the pipe body, which includes: 3D printing the tube structure; The inner channel of the outlet end and the circumference of the outlet end are treated with a hydrophilic and oleophobic material to form the oleophobic layer; The outer circumference of the outlet end is treated with hydrophilic and oleophilic materials to form the oleophilic and hydrophilic layer, which wraps the oleophobic layer.

5. A collection method according to claim 2, characterized in that: The method further includes fixing the tube body, which includes fixing the test chip and fixing the processed tube body above the test chip, wherein the tube body and the test chip do not contact each other.

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