Sensitivity gain electrode array electrochemical particle vibration velocity sensor and implementation method thereof
By introducing a gain electrode array structure into the electrochemical particle vibration speed sensor to adjust the ion concentration of the oxidant surface on the anode, the problem of limited sensitivity in the prior art is solved, and the sensitivity improvement and range adjustment are achieved, adapting to different application scenarios.
Patent Information
- Application Number
- CN202411249928.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2024-12-13
AI Technical Summary
The sensitivity of existing electrochemical particle vibration speed sensors is limited by the boundary effect and the difficulty of preparation process caused by the reduction of the distance between the anode and the reduction of the anode spacing, and the iodine tri-ion concentration on the anode surface is limited by the electrode area and ion diffusion, which is difficult to further improve.
Using a gain electrode array structure, by setting multiple gain electrodes on the inner wall of the package shell, connecting to zero potential, using the constant voltage output end of the external circuit to apply a positive voltage to the anode of the sensitive electrode chip, adjusting the concentration of the oxidant ion on the anode surface, and passing the gain The number of electrodes adjusts sensitivity and improves differential current response.
It effectively improves the sensitivity of the electrochemical particle vibration speed sensor, expands the distribution range of the anode surface ion concentration, realizes adjustable sensitivity, reduces device costs, and adapts to the range requirements of different test environments.
Smart Images
Figure CN119124336A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a vibration velocity sensing technology, and in particular to a sensitivity gain electrode array electrochemical particle vibration velocity sensor and an implementation method thereof. Background Art
[0002] Electrochemical particle vibration velocity sensors can be used to prepare electrochemical vibration sensors or electrochemical acoustic vector hydrophones, which have the advantages of low frequency noise. Electrochemical particle vibration velocity sensors are usually composed of electrolytes, sensitive electrode chips and packaging structures. Generally, sensitive electrode chips are 4-electrode structures, arranged in the manner of anode-cathode-cathode-anode, forming two pairs of electrodes. The main reaction ions in the solution system are generally iodine ions and iodine triions. After the system is energized, iodine ions and iodine triions are mutually converted on the electrodes. The anode oxidizes iodine ions to iodine triions, and the cathode reduces iodine triions to iodine ions. Generally speaking, the original iodine triion concentration in the solution is low, which is a key factor affecting the electrochemical reaction. In the absence of external interference, the distribution of iodine ions and iodine triions in the electrolyte gradually stabilizes, where the anode will gather iodine triions and the cathode will gather iodine ions. Due to the symmetrical structure, the output currents of the two pairs of electrodes are the same, and the output after differentiation is 0. When there is vibration or sound waves in the outside world, convection will occur in the electrolyte, changing the concentration distribution of the reaction ions near the electrodes. At this time, the working states of the two pairs of electrodes are no longer the same, resulting in an increase in the output current of one pair of electrodes and a decrease in the output current of the other pair, thereby changing the differential current. The differential current represents the size of the convection, which also represents the strength of the external vibration or sound waves.
[0003] An important determinant of the sensitivity of existing electrochemical particle velocity sensors is the iodine triion concentration gradient between the positive and negative electrodes. Since the iodine triion concentration on the cathode surface is generally considered to be 0, the distance between the positive and negative electrodes and the ion concentration on the anode surface are the key factors. Many solutions in the past have improved the sensitivity by reducing the distance between the positive and negative electrodes. This direction is now difficult to further reduce. On the one hand, there is a boundary effect when reducing the electrode distance. As the minimum distance has been reduced to less than 2 microns, the improvement brought by further reduction is very limited. On the other hand, too small an electrode distance will greatly increase the difficulty of the device preparation process, resulting in a decrease in yield or an increase in cost.
[0004] Within a certain output range, the output amplitude of the device basically conforms to the following formula:
[0005] U=RqFAC A v
[0006] Among them, U is the output amplitude of the device, v is the external input speed, so the sensitivity is U / v=RqFAC AOverall, the output voltage of the device depends on the current-voltage conversion resistance coefficient R, A is the cross-sectional area of the flow channel, which can be understood as a parameter related to the electrode chip structure, C A is the concentration of iodine triions on the anode surface, q is the charge, and F is the Faraday constant.
[0007] The mainstream structure usually arranges the electrodes in the manner of anode-cathode-cathode-anode, which results in two cathodes being sandwiched by the anode in the center. The distance between the two cathodes is extremely small, generally only a few hundred microns, which results in very little electrolyte near the cathode that can participate in the electrochemical reaction. In order to further solve the anode surface iodine triion concentration in the above formula, the ion concentration distribution is approximated by piecewise linearity, and combined with the law of conservation of matter, it can be concluded that the surface concentration of iodine triion at the anode of the electrochemical device conforms to the following formula:
[0008]
[0009] Where C A represents the concentration of iodine triions on the anode surface, S c represents the anode area, S A represents the cathode area, D represents the distance between the two cathodes, δ represents the anode ion diffusion distance, C 0 is the initial concentration of iodine triion in the electrolyte, C 0 ′ is the maximum concentration of iodine triions between the two cathodes. From this formula, we can conclude that increasing the cathode area can effectively increase the concentration on the anode surface, but the increase in the cathode area on the chip is limited by the device size and is difficult to expand further. Summary of the invention
[0010] In order to solve the above problems, the present invention proposes a sensitivity gain electrode array electrochemical particle vibration velocity sensor and an implementation method thereof, which improves the sensitivity of the electrochemical particle vibration velocity sensor by adding a gain electrode array, improves the utilization rate of ions in the electrolyte, and adjusts the ion concentration on the anode surface, thereby improving the sensitivity of the device and realizing device-level adjustment of the sensitivity.
[0011] One object of the present invention is to provide an electrochemical particle velocity sensor with a sensitivity gain electrode array.
[0012] The sensitivity gain electrode array electrochemical particle velocity sensor of the present invention comprises: a sensitive electrode chip, a packaging shell, a flexible film and a gain electrode array; wherein the sensitive electrode chip is located in the middle, and the packaging shell is arranged at the edge; the two ends of the packaging shell are open; the two ends of the packaging shell are respectively provided with flexible membranes for sealing; the electrolyte is filled in the sealed space formed by the packaging shell and the flexible membrane, the sensitive electrode chip is immersed in the electrolyte, the electrolyte contains oxidant ions and reductant ions, wherein the concentration of the reductant ions is much greater than the concentration of the oxidant ions; the cathode of the sensitive electrode chip is connected to the differential input end of the measurement module of the external circuit, and the anode is connected to the constant voltage output end of the power supply module of the external circuit;
[0013] The inner wall of the package shell is a gain horn structure, and the cross section parallel to the surface of the sensitive electrode chip is circular, and the area of the cross section increases in a direction away from the sensitive electrode chip;
[0014] A gain electrode array is arranged on the inner wall of the package shell; the gain electrode array includes a plurality of gain electrodes, and the plurality of gain electrodes are evenly and symmetrically distributed on the inner wall of the package shell; the area of each gain electrode is related to the area of the sensitive electrode chip and is not larger than the area of the sensitive electrode chip; each gain electrode is respectively connected in series with a corresponding switch to the zero potential of the power supply module of the external circuit;
[0015] A positive voltage is applied to the anode of the sensitive electrode chip through the constant voltage output end of the power supply module of the external circuit; when there is no external vibration signal, an oxidation reaction occurs at the anode, the reducing agent ions are oxidized to produce oxidant ions, and the oxidant ions participate in the reduction reaction at the cathode and are reduced to reducing agent ions. After the reaction is stable, a stable redox reaction occurs between the cathode and the anode. The reducing agent ions and the oxidant ions are collectively referred to as reaction ions. Under the diffusion of the reaction ions, a stable reaction ion concentration distribution field is formed between the cathode and the anode in a positive and negative electrode layer; when there is vibration or sound wave in the outside world, convection occurs in the electrolyte, which changes the concentration distribution of the reaction ions near the sensitive electrode chip, thereby changing the current size of the sensitive electrode chip, and transmitting it to the measurement module of the external circuit through two pairs of cathodes. The measurement module detects the differential current between the two pairs of cathodes, thereby obtaining external vibration or sound wave; at the same time, the gain electrode connected to the zero potential has the same potential as the cathode, and a reduction reaction occurs subsequently, reducing the oxidant ions around the gain electrode to reducing agent ions, and at the same time providing more electrons to the anode of the sensitive electrode chip. The anode obtains electrons, prompting more oxidation reactions at the anode, and The excess reducing agent ions around the anode are further consumed and converted into oxidizing agent ions that contribute to the sensitivity of the vibration velocity sensor. The concentration of oxidizing agent ions on the anode surface is increased, and the output is increased at this time, which is transmitted to the measurement module of the external circuit to improve the sensitivity of the vibration velocity sensor; and the gain electrode makes the upper limit of the sensitivity related to the concentration of the reducing agent ions. A higher reducing agent ion concentration further effectively improves the sensitivity of the electrochemical particle vibration velocity sensor; further, the maximum value of the output amplitude of the vibration velocity sensor, that is, the range, is determined by the power supply voltage of the external circuit. The greater the sensitivity of the vibration velocity sensor, the smaller the output range will be; according to the signal amplitude of the vibration or sound wave being tested, the range is adjusted. If the signal amplitude being tested exceeds the current range, by closing one or more switches connected in series to each gain electrode, the number of gain electrodes participating in the reaction is reduced, the sensitivity is reduced, and the output range is increased; if the signal amplitude being tested is much smaller than the current range, by opening one or more switches connected in series to each gain electrode, the number of gain electrodes participating in the reaction is increased, the sensitivity is improved, and the output range is reduced to achieve a variable range.
[0016] The sensitive electrode chip includes two pairs of positive and negative electrode layers and an insulating layer; each pair of positive and negative electrode layers includes a substrate, a cathode and an anode; a plurality of two-dimensionally arranged flow holes penetrating two surfaces are opened on the substrate to form a flow hole array, an anode is prepared on one surface of the substrate, and a cathode is prepared on the other surface and the inner wall of the through hole; the cathode and anode on each pair of positive and negative electrode layers are insulated; the cathode on each pair of positive and negative electrode layers is connected to the differential input end of the measurement module of the external circuit, and the anode is connected to the constant voltage output end of the power supply module of the external circuit; the cathodes of the two pairs of positive and negative electrode layers are located on the inner side and placed oppositely to form an arrangement of anode-cathode-cathode-anode, and the edges between the two pairs of positive and negative electrode layers are sealed with a ring-shaped insulating layer. The substrate has good support and insulation effects, and adopts a flexible substrate of silicon, glass or polydimethylsiloxane (PDMS), or a composite substrate bonded with multiple materials of silicon glass; the cathode and anode have good stability in the electrolyte, and adopt platinum, graphite, graphene or silicon.
[0017] The electrolyte is an electrochemical reaction system with good reversibility of bromine-bromide, ferrocyanide-ferrocyanide or iodine-iodide. For the convenience of the following description, the system composed of iodine-potassium iodide is uniformly described, iodine ion is the reducing agent ion, and iodine triion is the oxidizing agent ion. When iodine, potassium iodide and deionized water are mixed in a certain ratio to obtain an electrolyte, the amount of iodine added in the common ratio is 0.1-0.01 mol / L, and the concentration of potassium iodide in the electrolyte is 4-6 mol / L. In the existing electrolyte system, the concentration of potassium iodide does not play a decisive role in the output of the device. The electrochemical particle vibration velocity sensor of the present invention adopts a gain electrode, and the upper limit of the sensitivity is related to the concentration of potassium iodide. Increasing the concentration of potassium iodide can effectively improve the sensitivity expansion range of the electrochemical particle vibration velocity sensor with a gain electrode structure. Therefore, the concentration of potassium iodide in the electrolyte of the present invention is higher than the common 2-4 mol / L level. The iodine element in the system will react with iodide ions to generate iodine triions. The electrolysis system mainly undergoes mutual conversion between iodine ions and iodine triions.
[0018] The material of the package shell is made of materials with good insulation and chemical inertness, such as organic glass. The flexible film is made of rubber, polyurethane, nanot or polyimide, and different soft and hard materials are selected according to the required parameters. The sensitive electrode chip is sealed in the package shell and the flexible film to ensure that the electrolyte does not leak out and is well insulated from the outside.
[0019] The gain electrode is made of pure platinum sheet, platinum-plated titanium, silicon, glass or platinum grown on a flexible substrate or titanium-plated platinum black, and has good corrosion resistance; the metal used in the gain electrode needs to be the same as the metal on the sensitive electrode chip to ensure that the gain electrode and the cathode have the same potential. For hard gain electrodes made of pure platinum sheet, platinum-plated titanium, and platinum grown on silicon glass, directly use back soldering and apply photosensitive glue (UV glue) to electrically insulate the solder joints; for gain electrodes made of platinum grown on a flexible substrate, use conductive silver glue to connect, and use UV glue to protect the bonding points to enhance strength.
[0020] A single gain electrode is not larger than the area of the sensitive electrode chip of the electrochemical device. An overly large area will reduce the graduation value of the sensitivity adjustment. It is usually analyzed that the concentration of the reductant ions in the solution is much greater than that of the oxidant ions. As the area of the gain electrode gradually increases, the reductant ions on the anode surface are continuously converted into oxidant ions. Finally, the device will be limited by the concentration of the reductant ions in the solution, resulting in device failure. The gain electrode is another new electrode structure independent of the traditional anode and cathode structure. It is different from the cathode in function. There is generally a current-voltage conversion circuit and a differential circuit behind the cathode to process the current size information on it, and therefore the zero potential connected to the cathode is generally the virtual ground of the operational amplifier; while the gain electrode array is only responsible for collecting oxidant ions. In order not to interfere with the original differential output working mode of the device and not to affect the symmetry of the device, the gain electrode will not output a signal, so it is directly connected to the zero potential in the power supply module. The gain electrode array is installed in the packaging structure at a position more than 5mm away from the sensitive electrode chip to avoid affecting the concentration distribution near the sensitive electrode chip.
[0021] The gain electrode array includes 2 to 8 gain electrodes; in order to collect ions more effectively, the distance between these gain electrodes is greater than the size of a single gain electrode; close arrangement can also achieve a gain effect, but it will reduce the working efficiency of the gain electrode. The structure of the sensitive electrode chip will also affect the number of gain electrodes. The higher the ratio of the cathode to the anode area on the sensitive electrode chip, the fewer gain electrodes can be added. The larger the single area of the gain electrode, the fewer the number of gain electrodes. The higher the ratio of the iodine element to the potassium iodide added in the electrolyte, the fewer the number of gain electrodes that can be installed. The sensitivity of the device can be adjusted by adjusting the number of gain electrodes connected, and the initial sensitivity of the device can be restored by disconnecting the gain electrodes.
[0022] The sensitivity gain electrode array electrochemical particle velocity sensor is powered by a DC power supply, which is a positive and negative power supply with a voltage value of 8 to 15 volts. The power supply module of the external circuit converts the 15V external power supply voltage into an electrolysis voltage of 0.3 to 1.2V through a linear voltage regulator. The voltage amplitude of the electrolysis voltage applied to the anode of the sensitive electrode chip through the positive terminal is 0.3 to 1.2V.
[0023] The sensitivity of the electrochemical vibration detector is limited by the amplitude of the power supply voltage. The maximum output range of the particle velocity sensor is equal to the maximum power supply voltage divided by the sensitivity. Therefore, by changing the number of gain electrodes connected to adjust the sensitivity, the range of the particle velocity sensor can also be adjusted to adapt to different test environments and requirements.
[0024] The gain horn structure adopts one of the following: a sudden change in diameter of a straight tube horn, a linear change in diameter of a double cone horn, a parabola horn and an exponential horn whose diameter changes along a special function. The parabola horn has the greatest gain effect and the largest effective range, followed by the exponential horn, the cone horn, and the straight tube horn has almost no gain. Different types of gain horns are selected for different processing capabilities. The cone horn and the straight tube horn are easy to process, while the parabola horn and the exponential horn have good gain effects.
[0025] Another object of the present invention is to provide a method for realizing an electrochemical particle vibration velocity sensor with a sensitivity gain electrode array.
[0026] The method for realizing the sensitivity gain electrode array electrochemical particle vibration velocity sensor of the present invention comprises the following steps:
[0027] 1) Preparation of electrochemical particle velocity sensor:
[0028] a) Two pairs of positive and negative electrode layers are sandwiched by two circuit boards, and an annular insulating layer is used to seal the two pairs of positive and negative electrode layers to form a sensitive electrode chip, and the cathode and anode of the positive and negative electrode layers are respectively connected to the circuit board by gold wire welding, and the circuit board plays the role of electrical extraction and support protection;
[0029] b) squeezing the sandwiched sensitive electrode chip in the middle of the packaging shell, the packaging shell is in the shape of a trumpet mouth to amplify the sound waves or vibrations;
[0030] c) Connect the back side of the gain electrode to the lead wire and glue it evenly and symmetrically on the inner wall of the package shell, at least 5 mm away from the sensitive electrode chip;
[0031] d) Flexible membrane seals are respectively arranged at both ends of the packaging shell to form a sealed space, a metal flange is used to mechanically compress the flexible membrane, and a rubber ring is used to ensure the seal;
[0032] e) injecting an electrolyte into the sealed space formed by the packaging shell and the flexible film, wherein the electrolyte contains oxidant ions and reductant ions, wherein the concentration of the reductant ions is much greater than the concentration of the oxidant ions, and the packaging shell is reserved with two injection holes to maintain air pressure balance, and after injection and degassing, an electrochemical particle vibration velocity sensor is obtained;
[0033] 2) The cathode of the sensitive electrode chip is connected to the differential input terminal of the measurement module of the external circuit, and the anode is connected to the constant voltage output terminal of the power supply module of the external circuit; the gain electrode is connected to the zero potential of the power supply module of the external circuit;
[0034] 3) applying a positive voltage to the anode of the sensitive electrode chip through the constant voltage output terminal of the power supply module of the external circuit;
[0035] 4) When there is no external vibration signal, an oxidation reaction occurs at the anode, the reductant ions are oxidized to produce oxidant ions, and the oxidant ions participate in the reduction reaction at the cathode and are reduced to reductant ions. After the reaction stabilizes, a stable redox reaction occurs between the cathode and the anode. The reductant ions and the oxidant ions are collectively referred to as reaction ions. Under the diffusion of the reaction ions, a stable reaction ion concentration distribution field is formed between the cathode and the anode in a positive and negative electrode layer;
[0036] 5) When there is vibration or sound wave in the outside world, the electrolyte will have convection, which will change the concentration distribution of reactive ions near the sensitive electrode chip, and then change the current of the sensitive electrode chip, which will be transmitted to the measurement module of the external circuit through two pairs of cathodes. The measurement module detects the differential current between the two pairs of cathodes, thereby obtaining external vibration or sound wave;
[0037] 6) At the same time, the gain electrode connected to the zero potential has the same potential as the cathode, and a reduction reaction occurs, reducing the oxidant ions around the gain electrode to reducing agent ions, and at the same time providing more electrons to the anode of the sensitive electrode chip. The anode obtains electrons, prompting more oxidation reactions to occur at the anode, further consuming the excess reducing agent ions around the anode and converting them into oxidant ions that contribute to the sensitivity of the vibration velocity sensor. The oxidant ion concentration on the anode surface is increased, and at this time the output is increased and transmitted to the measurement module of the external circuit, thereby improving the sensitivity of the vibration velocity sensor;
[0038] 7) Moreover, the gain electrode makes the upper limit of sensitivity related to the concentration of reducing agent ions, and a higher reducing agent ion concentration further effectively improves the sensitivity of the electrochemical particle vibration velocity sensor;
[0039] 8) The maximum value of the output amplitude of the vibration velocity sensor, i.e., the range, is determined by the power supply voltage of the external circuit. The greater the sensitivity of the vibration velocity sensor, the smaller the output range will be. The range is adjusted according to the signal amplitude of the vibration or sound wave being tested. If the signal amplitude being tested exceeds the current range, one or more switches connected in series to each gain electrode are closed to reduce the number of gain electrodes participating in the reaction, thereby reducing the sensitivity and increasing the output range. If the signal amplitude being tested is much smaller than the current range, one or more switches connected in series to each gain electrode are opened to increase the number of gain electrodes participating in the reaction, thereby increasing the sensitivity and reducing the output range to achieve a variable range.
[0040] Advantages of the present invention:
[0041] (1) The present invention can significantly improve the sensitivity of the device, and the gain multiple can be conveniently adjusted according to factors such as the number and position of the gain electrode array;
[0042] (2) This method can adjust the range of the device. By connecting different numbers of gain electrodes, the range of the device is also different, which can adapt to different application scenarios;
[0043] (3) The utilization rate of the electrolyte is improved, and the electrolyte far away from the chip can be used more effectively, so that the reaction range is no longer limited by the chip area, and the ion concentration on the anode surface is effectively increased;
[0044] (4) It is universal for electrochemical vibration detectors, hydrophones and other equipment, and can effectively improve the sensitivity of the equipment without adding additional process steps;
[0045] (5) It can reduce the high-frequency noise of the device and improve the trend of the high-frequency noise curve, which is of great significance for underwater application scenarios;
[0046] (6) Compared with the traditional method of improving sensitivity through device design, the present invention has low cost, outstanding gain effect, and does not conflict with the optimization direction of structural design, and can be used in combination to further improve sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS
[0047] Figure 1 A cross-sectional view of an embodiment of the sensitivity gain electrode array electrochemical particle velocity sensor of the present invention;
[0048] Figure 2 A cross-sectional view of a sensitive electrode chip of an embodiment of the sensitivity gain electrode array electrochemical particle vibration velocity sensor of the present invention;
[0049] Figure 3Schematic diagrams of gain electrodes of different structures of an embodiment of the sensitivity gain electrode array electrochemical particle vibration velocity sensor of the present invention, wherein (a) to (c) are schematic diagrams of structures of different gain electrodes respectively;
[0050] Figure 4 A schematic diagram of a gain electrode array connection switch of an embodiment of a sensitivity gain electrode array electrochemical particle vibration velocity sensor of the present invention;
[0051] Figure 5 This is a schematic diagram of the sensitive electrode chip lead-out of an embodiment of the sensitivity gain electrode array electrochemical particle velocity sensor of the present invention. DETAILED DESCRIPTION
[0052] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.
[0053] like Figure 1 As shown, the sensitivity gain electrode array electrochemical particle velocity sensor of this embodiment includes: a sensitive electrode chip 1, a packaging shell 2, a flexible film 4 and a gain electrode array 5; wherein the sensitive electrode chip 1 is located in the middle, and the packaging shell 2 is arranged on the edge; the two ends of the packaging shell 2 are open; the flexible films 4 are respectively arranged at the two ends of the packaging shell 2 for sealing; the electrolyte is filled in the sealed space formed by the packaging shell 2 and the flexible film 4, and the sensitive electrode chip 1 is immersed in the electrolyte, the potassium iodide concentration in the electrolyte is 5 mol / L, and the amount of iodine added is 0.1 mol / L; the cathode of the sensitive electrode chip 1 is connected to the differential input end of the external circuit measurement module, and the anode is connected to the constant voltage output end of the external circuit power supply module; the gain electrode array 5 is pasted on the inner wall of the packaging shell 2 and connected to the zero potential of the power supply module;
[0054] The inner wall of the package shell 2 is a gain horn structure, the cross section parallel to the surface of the sensitive electrode chip 1 is circular, the area of the cross section increases as it moves away from the sensitive electrode chip 1, and the cross section of the inner wall perpendicular to the surface of the sensitive electrode chip 1 is a curve;
[0055] A gain electrode array 5 is arranged on the inner wall of the packaging shell 2; the gain electrode array 5 includes a plurality of gain electrodes, and the plurality of gain electrodes are evenly and symmetrically distributed on the inner wall of the packaging shell 2; the area of each gain electrode is related to the area of the sensitive electrode chip 1 and is not greater than the area of the sensitive electrode chip 1.
[0056] like Figure 2As shown, the sensitive electrode chip 1 includes two pairs of anode and cathode electrode layers and an insulating layer 3; each pair of anode and cathode electrode layers includes a substrate 11, a cathode 12 and an anode 13; a plurality of two-dimensionally arranged flow holes penetrating the two surfaces are opened on the substrate 11 to form a flow hole array, an anode 13 is prepared on one surface of the substrate 11, and a cathode 12 is prepared on the other side surface and the inner wall of the through hole; the cathode 12 and the anode 13 on each pair of anode and cathode electrode layers are insulated; the cathode 12 on each pair of anode and cathode electrode layers is connected to the differential input terminal of the measurement module of the external circuit, and the anode 13 is connected to the constant voltage output terminal of the power supply module of the external circuit; the cathodes 12 of the two pairs of anode and cathode electrode layers are located on the inner side and placed opposite to each other to form an anode-cathode-cathode-anode arrangement, and the edges between the two pairs of anode and cathode electrode layers are sealed with a ring-shaped insulating layer.
[0057] Figure 3 (a) is a gain electrode made of titanium plated with platinum, wherein 52 is titanium metal, which plays a supporting and conductive role, 51 is platinum metal plated on its upper and lower surfaces, and the wire 54 is soldered to the back of the gain electrode by soldering 55, and UV glue 53 is used to cover the solder joints and the back of the electrode to protect the solder joints and control the uniformity of the gain electrode area. Figure 3 (b) is a gain electrode made of pure platinum sheet, and its manufacturing process is almost the same as that of the titanium-plated platinum electrode; Figure 3 (c) is a flexible gain electrode prepared by MEMS technology. The base material 57 is PDMS. Platinum metal 51 is sputtered on the surface of PDMS. After slicing, small pieces of flexible electrodes are obtained, which are more closely attached to the inner wall of the package. At the same time, since the metal layer on the surface of the flexible electrode is very thin, conductive silver glue 56 is used to connect the wire 54 to its surface. After the conductive silver glue is cured, UV glue 53 is used to apply it to protect the silver glue and increase the connection strength at this point.
[0058] like Figure 4 As shown, each gain electrode 41 is respectively connected in series with a corresponding switch 43 to be connected to the zero potential 42 of the power supply module of the external circuit.
[0059] In this embodiment, the substrate is made of single crystal silicon; the cathode and anode are made of 20nm chromium and 200nm platinum metal prepared by magnetron sputtering; the potassium iodide concentration in the electrolyte is 5mol / L, and the amount of iodine added is 0.1mol / L. The material of the package shell 2 is organic glass; the flexible film 4 is made of fluororubber; the gain electrode is made of titanium plated with platinum, directly back soldering is used, and the solder joints are electrically insulated and protected by coating with UV glue; the gain electrode array 5 includes 8 gain electrodes; the gain speaker structure adopts a double cone speaker with linearly changing tube diameter.
[0060] The method for realizing the sensitivity gain electrode array 5 electrochemical particle vibration velocity sensor of this embodiment includes the following steps:
[0061] 1) Preparation of electrochemical particle velocity sensor:
[0062] a) preparing a single crystal silicon wafer with a thickness of 300 microns, preparing a 20-nanometer-thick chromium layer by evaporation or magnetron sputtering, and then preparing a 200-nanometer-thick platinum metal layer on the chromium, the chromium metal plays an adhesion role, spin-coating a photoresist on the metal surface, and then exposing a regularly arranged circular hole array on the surface of the silicon wafer, the diameter of the circular hole can be 60-120 microns, etching away the exposed chromium-platinum metal by an IBE etching scheme, and obtaining a silicon wafer with a surface metal pattern after de-resisting;
[0063] Photolithography is performed on the back of the silicon wafer. The photolithography pattern is a circular hole array with the same position arrangement as the previous photolithography. However, the diameter of the circular hole needs to be slightly smaller than the previous photolithography, which is 50 to 100 microns. A thick mask is prepared, and then an aluminum liner is attached to the silicon wafer and DRIE etching is performed to completely etch through the silicon wafer. The etched circular holes should be aligned with the pattern in the previous step to ensure that the two structures are coaxial.
[0064] Since the insulation performance of pure silicon wafers is insufficient, a 100-nanometer silicon oxide layer is grown by thermal oxidation for insulation, thereby preparing a dense silicon oxide insulation layer;
[0065] A magnetron sputtering is performed on the back to prepare chromium-platinum metal, and the back of the chip and the inner wall of the flow hole are covered with metal;
[0066] The silicon wafer is sliced at a step size to obtain a layer having a pair of positive and negative electrodes, such as Figure 3 As shown;
[0067] Take two sheets of positive and negative electrode layers, place the surfaces subjected to the second magnetron sputtering opposite to each other, sandwich an insulating rubber pad made of fluororubber with a thickness of 0.5 mm in the middle, and use a small amount of polyurethane glue to simply fix them to ensure that the upper and lower flow holes are basically aligned, and then press them tightly to form a sensitive electrode chip 1;
[0068] like Figure 5 As shown, the sensitive electrode chip 1 is sandwiched between two circuit boards 62, sealed with a fluoro rubber pad 63 in the middle, and the electrode is connected to the circuit board by gold wire welding 61, and the circuit board plays the role of electrical extraction and support protection;
[0069] b) squeezing the sensitive electrode chip 1 sandwiched by the circuit board into the middle of the package shell 2, the package shell 2 is in the shape of a trumpet to amplify the sound waves or vibrations;
[0070] c) Connect the back side of the gain electrode to the lead wire and glue it evenly and symmetrically to the inner wall of the package shell 2, at a distance of more than 5 mm from the sensitive electrode chip;
[0071] d) Flexible membranes 4 are respectively provided at both ends of the packaging shell 2 to form a sealed space, the flexible membrane 4 is mechanically compressed by a metal flange, and a rubber ring is used to ensure the seal;
[0072] e) injecting electrolyte into the sealed space formed by the packaging shell 2 and the flexible membrane 4 through the injection hole reserved in the packaging shell 2, the packaging shell 2 reserves two injection holes to maintain air pressure balance, and obtaining the electrochemical particle vibration velocity sensor after injection and degassing;
[0073] 2) The cathode of the sensitive electrode chip 1 is connected to the differential input terminal of the measurement module of the external circuit, the anode is connected to the constant voltage output terminal of the power supply module of the external circuit, and the gain electrode is connected to the zero potential of the power supply module;
[0074] 3) applying a positive voltage to the anode of the sensitive electrode chip 1 through the constant voltage output terminal of the power supply module of the external circuit;
[0075] 4) When there is no external vibration signal, an oxidation reaction occurs at the anode to oxidize iodine ions to produce triiodine ions, and a reduction reaction occurs at the cathode to reduce triiodine ions to produce iodine ions. After the reaction stabilizes, a stable redox reaction occurs between the cathode and the anode. Under the diffusion of the reaction ions, a stable reaction ion concentration distribution field is formed between the cathode and the anode in a positive and negative electrode layer;
[0076] 5) When there is vibration or sound wave in the outside world, the electrolyte will have convection, which will change the concentration distribution of reactive ions near the sensitive electrode chip 1, and then change the current of the sensitive electrode chip 1, which will be transmitted to the measurement module of the external circuit through the two pairs of cathodes. The measurement module detects the differential current between the two pairs of cathodes, thereby obtaining the external vibration or sound wave;
[0077] 6) At the same time, the gain electrode connected to the zero potential has the same potential as the cathode, and a reduction reaction occurs to reduce the iodine triions around the gain electrode to iodine ions. At the same time, more electrons are provided to the anode of the sensitive electrode chip 1. The anode obtains electrons, which prompts more oxidation reactions to occur at the anode, further consuming the excess iodine ions around the anode and converting them into iodine triions that contribute to the sensitivity of the vibration velocity sensor. The iodine triion concentration on the anode surface is increased, and the output is increased at this time, which is transmitted to the measurement module of the external circuit, thereby improving the sensitivity of the vibration velocity sensor;
[0078] 7) Moreover, the gain electrode makes the upper limit of sensitivity related to the potassium iodide concentration, and a higher potassium iodide concentration further effectively increases the sensitivity extension range of the electrochemical particle vibration velocity sensor;
[0079] 8) The maximum value of the output amplitude of the vibration velocity sensor, i.e., the range, is determined by the power supply voltage of the measurement module of the external circuit. The greater the sensitivity of the vibration velocity sensor, the smaller the output range will be. The range is adjusted according to the signal amplitude of the vibration or sound wave being tested. If the signal amplitude being tested exceeds the current range, one or more switches connected in series to each gain electrode are turned off to reduce the number of gain electrodes participating in the reaction, thereby reducing the sensitivity and thus increasing the output range. If the signal amplitude being tested is much smaller than the current range, one or more switches connected in series to each gain electrode are turned on to increase the number of gain electrodes participating in the reaction and thus increasing the sensitivity.
[0080] Thereby reducing the output range and achieving a variable range.
[0081] Finally, it should be noted that the purpose of publishing the embodiments is to help further understand the present invention, but those skilled in the art can understand that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the contents disclosed in the embodiments, and the scope of protection claimed by the present invention shall be subject to the scope defined in the claims.
Claims
1. A sensitivity gain electrode array electrochemical particle vibration velocity sensor, characterized in that: The electrochemical particle velocity sensor comprises: a sensitive electrode chip, a packaging shell, a flexible membrane and a gain electrode array; wherein the sensitive electrode chip is located in the middle, and the packaging shell is arranged at the edge; the two ends of the packaging shell are open; the two ends of the packaging shell are respectively provided with flexible membrane seals; the electrolyte is filled in the sealed space formed by the packaging shell and the flexible membrane, the sensitive electrode chip is immersed in the electrolyte, the electrolyte contains oxidant ions and reductant ions, wherein the concentration of the reductant ions is much greater than the concentration of the oxidant ions; the cathode of the sensitive electrode chip is connected to the differential input end of the measurement module of the external circuit, and the anode is connected to the constant voltage output end of the power supply module of the external circuit; The inner wall of the package shell is a gain horn structure, and the cross section parallel to the surface of the sensitive electrode chip is circular, and the area of the cross section increases in a direction away from the sensitive electrode chip; A gain electrode array is arranged on the inner wall of the package shell; the gain electrode array includes a plurality of gain electrodes, and the plurality of gain electrodes are evenly and symmetrically distributed on the inner wall of the package shell; the area of each gain electrode is related to the area of the sensitive electrode chip and is not larger than the area of the sensitive electrode chip; each gain electrode is respectively connected in series with a corresponding switch to the zero potential of the power supply module of the external circuit; A positive voltage is applied to the anode of the sensitive electrode chip through the constant voltage output end of the power supply module of the external circuit; when there is no external vibration signal, an oxidation reaction occurs at the anode, the reducing agent ions are oxidized to produce oxidant ions, and the oxidant ions participate in the reduction reaction at the cathode and are reduced to reducing agent ions. After the reaction is stable, a stable redox reaction occurs between the cathode and the anode. The reducing agent ions and the oxidant ions are collectively referred to as reactive ions. Under the diffusion of reactive ions, a stable reactive ion concentration distribution field is formed between the cathode and the anode in a positive and negative electrode layer; when there is external vibration or sound wave, convection occurs in the electrolyte, which changes the concentration distribution of reactive ions near the sensitive electrode chip, thereby changing the current of the sensitive electrode chip, and transmitting it to the measurement module of the external circuit through two pairs of cathodes. The measurement module detects the differential current between the two pairs of cathodes, thereby obtaining external vibration or sound wave; at the same time, the gain electrode connected to the zero potential has the same potential as the cathode, and a reduction reaction occurs, reducing the oxidant ions around the gain electrode to reducing agent ions, and at the same time providing more electrons to the anode of the sensitive electrode chip. The anode obtains electrons, which promotes more oxidation reactions at the anode. The excess reducing agent ions around the anode are further consumed and converted into oxidizing agent ions that contribute to the sensitivity of the vibration velocity sensor. The concentration of oxidizing agent ions on the anode surface is increased, and the output is increased at this time, which is transmitted to the measurement module of the external circuit to improve the sensitivity of the vibration velocity sensor; and the gain electrode makes the upper limit of the sensitivity related to the concentration of the reducing agent ions. A higher reducing agent ion concentration effectively improves the sensitivity of the electrochemical particle vibration velocity sensor; further, the maximum value of the output amplitude of the vibration velocity sensor, that is, the range, is determined by the power supply voltage of the external circuit. The greater the sensitivity of the vibration velocity sensor, the smaller the output range will be; according to the signal amplitude of the vibration or sound wave being tested, the range is adjusted. If the signal amplitude being tested exceeds the current range, by closing one or more switches connected in series to each gain electrode, the number of gain electrodes participating in the reaction is reduced, the sensitivity is reduced, and the output range is increased; if the signal amplitude being tested is much smaller than the current range, by opening one or more switches connected in series to each gain electrode, the number of gain electrodes participating in the reaction is increased, the sensitivity is improved, and the output range is reduced to achieve a variable range.
2. The electrochemical particle vibration velocity sensor according to claim 1, characterized in that: The sensitive electrode chip includes two pairs of cation and cathode electrode layers and an insulating layer; each pair of cation and cathode electrode layers includes a substrate, a cathode and an anode; a plurality of two-dimensionally arranged flow holes penetrating two surfaces are opened on the substrate to form a flow hole array, an anode is prepared on one surface of the substrate, and a cathode is prepared on the other surface and the inner wall of the through hole; the cathode and anode on each pair of cation and cathode electrode layers are insulated; the cathode on each pair of cation and cathode electrode layers is connected to the differential input terminal of the measurement module of the external circuit, and the anode is connected to the constant voltage output terminal of the power supply module of the external circuit; the cathodes of the two pairs of cation and cathode electrode layers are located on the inner side and placed opposite to each other to form an anode-cathode-cathode-anode arrangement, and the edges between the two pairs of cation and cathode electrode layers are sealed with a ring-shaped insulating layer.
3. The electrochemical particle vibration velocity sensor according to claim 1, characterized in that: The electrolyte uses bromine-bromide, ferrocyanide-ferrocyanide or iodine-iodide.
4. The electrochemical particle vibration velocity sensor according to claim 3, characterized in that: The electrolyte uses iodine-iodide, and the concentration of potassium iodide in the electrolyte is 4-6 mol / L.
5. The electrochemical particle vibration velocity sensor according to claim 1, characterized in that: The flexible film is made of rubber, polyurethane, nanotek or polyimide.
6. The electrochemical particle vibration velocity sensor according to claim 1, characterized in that: The gain electrode is a pure platinum sheet, titanium plated with platinum, silicon, glass or platinum grown on a flexible substrate or titanium plated with platinum black.
7. The electrochemical particle vibration velocity sensor according to claim 1, characterized in that: The gain electrode array is more than 5 mm away from the sensitive electrode chip.
8. The electrochemical particle vibration velocity sensor according to claim 1, characterized in that: The gain electrode array includes 2 to 8 gain electrodes.
9. The electrochemical particle vibration velocity sensor according to claim 1, characterized in that: The gain horn structure adopts one of a sudden change straight tube horn, a double cone horn with a linearly changing tube diameter, a parabolic horn with a tube diameter changing along a special function, and an exponential horn.
10. A method for realizing the sensitivity gain electrode array electrochemical particle vibration velocity sensor as claimed in claim 1, characterized in that: The implementation method comprises the following steps: 1) Preparation of electrochemical particle velocity sensor: a) Two pairs of positive and negative electrode layers are sandwiched by two circuit boards, and an annular insulating layer is used to seal the two pairs of positive and negative electrode layers to form a sensitive electrode chip, and the cathode and anode of the positive and negative electrode layers are respectively connected to the circuit board by gold wire welding, and the circuit board plays the role of electrical extraction and support protection; b) squeezing the sandwiched sensitive electrode chip in the middle of the packaging shell, the packaging shell is in the shape of a trumpet mouth to amplify the sound waves or vibrations; c) Connect the back side of the gain electrode to the lead wire and glue it evenly and symmetrically on the inner wall of the package shell, at least 5 mm away from the sensitive electrode chip; d) Flexible membrane seals are respectively arranged at both ends of the packaging shell to form a sealed space, a metal flange is used to mechanically compress the flexible membrane, and a rubber ring is used to ensure the seal; e) injecting an electrolyte into the sealed space formed by the packaging shell and the flexible film, wherein the electrolyte contains oxidant ions and reductant ions, wherein the concentration of the reductant ions is much greater than the concentration of the oxidant ions, and the packaging shell is reserved with two injection holes to maintain air pressure balance, and after injection and degassing, an electrochemical particle vibration velocity sensor is obtained; 2) The cathode of the sensitive electrode chip is connected to the differential input terminal of the measurement module of the external circuit, and the anode is connected to the constant voltage output terminal of the power supply module of the external circuit; the gain electrode is connected to the zero potential of the power supply module of the external circuit; 3) applying a positive voltage to the anode of the sensitive electrode chip through the constant voltage output terminal of the power supply module of the external circuit; 4) When there is no external vibration signal, an oxidation reaction occurs at the anode, the reductant ions are oxidized to produce oxidant ions, and the oxidant ions participate in the reduction reaction at the cathode and are reduced to reductant ions. After the reaction stabilizes, a stable redox reaction occurs between the cathode and the anode. The reductant ions and the oxidant ions are collectively referred to as reaction ions. Under the diffusion of the reaction ions, a stable reaction ion concentration distribution field is formed between the cathode and the anode in a positive and negative electrode layer; 5) When there is vibration or sound wave in the outside world, the electrolyte will have convection, which will change the concentration distribution of reactive ions near the sensitive electrode chip, and then change the current of the sensitive electrode chip, which will be transmitted to the measurement module of the external circuit through two pairs of cathodes. The measurement module detects the differential current between the two pairs of cathodes, thereby obtaining external vibration or sound wave; 6) At the same time, the gain electrode connected to the zero potential has the same potential as the cathode, and a reduction reaction occurs, reducing the oxidant ions around the gain electrode to reducing agent ions, and at the same time providing more electrons to the anode of the sensitive electrode chip. The anode obtains electrons, prompting more oxidation reactions to occur at the anode, further consuming the excess reducing agent ions around the anode and converting them into oxidant ions that contribute to the sensitivity of the vibration velocity sensor. The oxidant ion concentration on the anode surface is increased, and at this time the output is increased and transmitted to the measurement module of the external circuit, thereby improving the sensitivity of the vibration velocity sensor; 7) Moreover, the gain electrode makes the upper limit of sensitivity related to the concentration of reducing agent ions, and a higher reducing agent ion concentration further effectively improves the sensitivity of the electrochemical particle vibration velocity sensor; 8) The maximum value of the output amplitude of the vibration velocity sensor, i.e., the range, is determined by the power supply voltage of the external circuit. The greater the sensitivity of the vibration velocity sensor, the smaller the output range will be. The range is adjusted according to the signal amplitude of the vibration or sound wave being tested. If the signal amplitude being tested exceeds the current range, one or more switches connected in series to each gain electrode are closed to reduce the number of gain electrodes participating in the reaction, thereby reducing the sensitivity and increasing the output range. If the signal amplitude being tested is much smaller than the current range, one or more switches connected in series to each gain electrode are opened to increase the number of gain electrodes participating in the reaction, thereby increasing the sensitivity and reducing the output range to achieve a variable range.