Self-powered seismic detector based on triboelectric and magnetoelectric combination and manufacturing method thereof

Abstract

The application provides a self-powered seismic detector based on triboelectricity and magnetoelectricity and a manufacturing method thereof. The detector comprises a triboelectricity sensitive unit and a magnetoelectricity sensitive unit which are combined with each other. The triboelectricity sensitive unit comprises an N-type magnet mass, a copper Z-shaped spring base, a PDMS friction pad and a signal lead-out wire. The signal lead-out wire is connected with a wireless data acquisition and conditioning circuit module. A power supply lead-out wire is connected with a power management module. The power management module is connected with the wireless data acquisition and conditioning circuit module. The self-powered cable-free seismic detector based on triboelectricity and magnetoelectricity obtained by using the manufacturing method has the advantages of simple and stable structure, light mass, strong anti-electromagnetic interference ability, high sensitivity, self-power supply and no need of external connecting cable. The detector is convenient for arrangement of field workers of seismic exploration and long-term data acquisition.

Description

Technical Field

[0001] This invention relates to the field of seismic detection, specifically to a self-powered seismic detector based on the combination of triboelectric and magnetoelectric power and its manufacturing method. Background Technology

[0002] Seismic detectors are a key component of seismic exploration equipment, and their performance determines the resolution, depth, and accuracy of seismic exploration. With advancements and breakthroughs in materials science, electronic information technology, and manufacturing technology, seismic detectors are rapidly developing towards miniaturization, low power consumption, wide frequency response, and networking. Traditional moving-coil seismic detectors, due to their heavy weight, complex manufacturing process, and poor low-frequency response, have caused numerous inconveniences for seismic exploration work. In recent years, triboelectric sensors have attracted widespread attention from researchers due to their promising applications in wearable electronics, artificial skin, vibration sensors, and energy harvesters. Since its discovery by Faraday in the 17th century, electromagnetic induction has been widely used in the conversion of mechanical energy into electrical energy. Magnetoelectric sensing units are characterized by large output current and high conversion efficiency when converting vibration into electrical energy. Breakthroughs in triboelectric sensing technology and magnetoelectric sensing technology have made it possible to manufacture simple, self-powered, wide-frequency response, cableless seismic detectors. Through structural design, the triboelectric sensing unit can convert the broadband vibration of the ground into a corresponding high-voltage output signal, while the magnetoelectric sensing unit can convert the mechanical energy contained in the vibration into high-current, high-power electrical energy.

[0003] Petroleum exploration refers to the process of finding and identifying oil and gas resources by using various exploration methods to understand underground geological conditions, determine the area of ​​oil and gas fields, and clarify the conditions and production capacity of oil and gas reservoirs. Seismic detectors, acting as the "stethoscope of the earth," are most widely used in petroleum exploration. They also have wide applications in ground fissure detection, coalbed methane development, debris flow early warning, and VSP logging. Currently, there are many types of seismic detectors, which can be classified into moving-coil, piezoelectric, digital, and fiber optic detectors based on their working principles. Among these, moving-coil seismic detectors are the most commonly used in geophysical exploration in onshore seismic exploration. While moving-coil seismic detectors are inexpensive, they suffer from high distortion, poor consistency, insufficient anti-interference capabilities, and a small dynamic range. Furthermore, moving-coil detectors are bulky, have poor shock resistance, and require numerous cable connections, causing considerable inconvenience in field seismic exploration. To improve the performance of the seismic detector, a triboelectric conversion unit can be used as the vibration sensing unit, and a magnetoelectric conversion unit as the energy storage unit. Through a rational structural design, the two conversion units are organically combined to maximize the conversion of mechanical energy, output a high-fidelity voltage signal related to the vibration signal, and obtain high-power electrical energy to power the sensor's built-in circuitry. The sensor's built-in circuitry implements a signal conditioning module for the triboelectric sensing unit, a power management circuit for the magnetoelectric energy storage unit, and a data acquisition and wireless transmission module, enabling the seismic detector to achieve cableless networking.

[0004] Triboelectric sensing elements utilize the triboelectric effect. When two different objects come into contact and rub against each other, the different affinities of the two materials for electrons cause electrons to transfer from one object to the other, resulting in equal amounts of opposite charges on the two objects. The material that easily loses electrons becomes positively charged and is called a positive triboelectric material, while the material that easily gains electrons becomes negatively charged and is called a negative triboelectric material. Currently reported triboelectric sensing elements are divided into four main categories: contact-separated, in-plane sliding, single-electrode, and non-contact triboelectric layer. The contact-separated triboelectric nanogenerator was the first to be reported. When two thin film materials with different dielectric constants come into mechanical contact, opposite charges are generated on the material surfaces. The thin film material that easily loses electrons becomes positively charged, and the thin film material that easily gains electrons becomes negatively charged. Once these two materials separate, a potential difference is generated between their electrodes. If a resistor is connected to the external circuit between the electrodes, free electrons will flow from one electrode to the other to balance the electrostatic field. As the distance between the two electrodes gradually decreases, the potential generated by the triboelectric charge disappears, and the induced electrons will flow in the opposite direction. The periodic contact and separation between the two materials will result in an alternating voltage signal between the two electrodes. Current research shows that the voltage signal output by the triboelectric sensing unit is extremely high, reaching 600V, but its output current is often small, usually in the μA range. Therefore, by integrating the positive and negative triboelectric materials into the spring-mass system model through reasonable structural design, the external vibration signal can be converted into a high-fidelity high-voltage signal. With reasonable conditioning circuit design, this voltage signal can be extracted, discretized, stored, and transmitted.

[0005] The electromagnetic induction phenomenon utilized by magnetoelectric sensing units is a widely applied energy conversion mechanism, and its theoretical model is well-known to most people. When a conductor cuts magnetic field lines in a magnetic field, an induced electromotive force (EMF) is generated in the conductor. When the conductor forms a circuit, an induced current is generated. In most linear vibration energy recovery devices, the coil and permanent magnet undergo one-dimensional relative motion, which causes a change in the magnetic flux in the closed coil, thus generating an induced EMF in the coil. Therefore, when vibration excitation in the external environment causes relative motion between the coil and the permanent magnet, since work must be done by overcoming electromagnetic forces (gravity or magnetic force), some mechanical energy needs to be converted into internal energy and released, while the remaining mechanical energy is converted into electrical energy. This electrical energy has the characteristics of high current and low voltage. By designing rectification and energy storage circuits, it can directly power the signal conditioning circuit, data acquisition system, and wireless transmission module inside the seismic detector.

[0006] Therefore, how to provide a self-powered cableless seismic detector that combines triboelectric and magnetoelectric sensing elements for long-term, high signal-to-noise ratio seismic data acquisition in the field has become a problem that needs to be solved. Summary of the Invention

[0007] To overcome the shortcomings of existing moving-coil seismic detectors, this invention provides a self-powered, cableless seismic detector based on the combination of triboelectric and magnetoelectric technologies, and its manufacturing method. This detector is a self-powered, cableless seismic detector that combines triboelectric and magnetoelectric technologies, and features high sensitivity, wide bandwidth, strong anti-interference capability, and wireless data transmission.

[0008] This invention is achieved through the following technical solution:

[0009] This invention provides a self-powered seismic detector based on the combination of triboelectric and magnetoelectric properties, comprising a right cover of a hollow semi-cylindrical seismic detector housing, a left cover of a seismic detector housing, and a triboelectric sensitive unit and a magnetoelectric sensitive unit that interact with each other located in the hollow cylindrical cavity formed by the right cover and the left cover of the seismic detector housing.

[0010] The triboelectric sensing unit includes an N-type magnet mass block located inside the cavity of a hollow cylindrical column; a copper Z-type spring base capable of elastic deformation, fixed between the upper end face of the N-type magnet mass block and the upper wall of the hollow cylindrical column; a lower copper Z-type spring base with the same structure as the upper copper Z-type spring base, fixed between the lower wall of the hollow cylindrical column and the N-type magnet mass block, also capable of elastic deformation; PDMS friction pads located on the upper and lower copper Z-type spring bases, rubbing against them; a positive signal lead connected to the upper copper Z-type spring base; and a signal lead connected to the lower copper Z-type spring base. The signal lead-out negative terminal, wherein the spring mass system consisting of the N-type magnet mass block, the upper copper Z-type spring base, and the lower copper Z-type spring base is used to convert the external vibration signal into the deformation of the upper copper Z-type spring base and the lower copper Z-type spring base; in the triboelectric couple consisting of the upper copper Z-type spring base, the lower copper Z-type spring base, and the PDMS friction pad, the upper copper Z-type spring base and the lower copper Z-type spring base serve as positive triboelectric materials, and the PDMS friction pad serves as negative triboelectric material. The PDMS friction pad includes a PDMS friction pad bump layer for charge transfer during contact friction and a PDMS friction pad bottom cavity for storing accumulated charge;

[0011] The magnetoelectric sensing unit includes an N-type magnet mass, an induction coil, an N-type magnet ring, a positive power transmission line, and a negative power transmission line. Symmetrically arranged semi-circular grooves for inserting and fixing the N-type magnet ring are located in the middle of the right and left covers of the seismic detector housing. The N-type magnet ring is fixed in the middle of the semi-circular grooves in the right and left covers of the seismic detector housing, within its inner cavity. The induction coil is fixed within the inner ring of the N-type magnet ring. In the induction coil, the N-magnet mass block is placed inside the induction coil and can move in a single axis inside the induction coil under the action of the N-type magnet ring and the induction coil. The terminals at both ends of the induction coil are connected to the positive and negative terminals of the power transmission line, respectively. The positive and negative terminals of the signal lead in the triboelectric sensing unit are connected to the built-in circuit board in the inner cavity of the hollow cylindrical column. The terminals at both ends of the induction coil in the magnetoelectric sensing unit are connected to the built-in circuit board through the positive and negative terminals of the power transmission line, respectively.

[0012] Further technical solutions include:

[0013] Both the upper and lower copper Z-shaped spring bases consist of a double-layer Z-shaped structure composed of three horizontal sections evenly spaced from top to bottom and two inclined sections connecting adjacent horizontal sections. A layer of PDMS friction pads is fixedly installed on the lower surface of the uppermost horizontal section, the upper and lower surfaces of the middle horizontal section, and the upper surface of the lower horizontal section. The uppermost horizontal section of the upper copper Z-shaped spring base is fixedly connected to the inner surface of the upper wall of the hollow cylindrical column. The lowermost horizontal section of the upper copper Z-shaped spring base is fixedly connected to the upper end face of the N-type magnet mass block. The uppermost horizontal section of the lower copper Z-shaped spring base is fixedly connected to the lower end face of the N-type magnet mass block. The lowermost horizontal section of the lower copper Z-shaped spring base is fixedly connected to the inner surface of the lower wall of the hollow cylindrical column.

[0014] The PDMS friction pad includes a bump layer for charge transfer during contact friction and a bottom cavity for storing accumulated charge. The PDMS friction pad frame around the bottom cavity is fixedly connected to the horizontal portion of the upper copper Z-shaped spring base and the horizontal portion of the lower copper Z-shaped spring base.

[0015] The N-type magnet ring installed in the cavity of the hollow cylindrical column is a ring structure made of bonded neodymium iron boron material. After the outer and inner circumferences of the N-type magnet ring are unipolar magnetized, the outer circumference of the N-type magnet ring has an S pole and the inner circumference has an N pole.

[0016] The outer periphery of the N-type magnet mass block has an N pole and the inner periphery has an S pole, while the outer periphery of the N-type magnet ring has an S pole and the inner periphery has an N pole.

[0017] The edge where the right cover of the seismic detector housing meets the left cover has two notches, located above and below the N-type magnet ring respectively. The edge where the left cover meets the right cover has two notches symmetrically positioned to match the notch on the right cover. When the right and left covers meet, the two notches on the right cover and the two notches on the left cover form two through-holes for wiring. The circuit board is circular and surrounds the lower copper Z-shaped spring base. The middle of the right cover and the middle of the left cover of the seismic detector housing have symmetrically arranged semi-circular grooves for inserting and fixing the built-in circuit board. The built-in circuit board is fixed in the semi-circular groove in the middle of the right cover and the middle of the left cover of the seismic detector housing. The positive terminals of the signal lead and the power transmission line pass through the upper wiring through hole and enter through the lower wiring through hole to connect with the built-in circuit board.

[0018] The inner upper wall of the right cover and the inner upper wall of the left cover of the seismic detector housing have symmetrically arranged slots for inserting and fixing the uppermost horizontal part of the upper copper Z-shaped spring base. The inner lower wall of the right cover and the inner lower wall of the left cover of the seismic detector housing have symmetrically arranged slots for inserting and fixing the lowermost horizontal part of the lower copper Z-shaped spring base. The uppermost horizontal part of the upper copper Z-shaped spring base is inserted and fixed in the slots on the inner upper wall of the right cover and the inner upper wall of the left cover of the seismic detector housing. The lowermost horizontal part of the lower copper Z-shaped spring base is inserted and fixed in the slots on the inner lower wall of the right cover and the inner lower wall of the left cover of the seismic detector housing.

[0019] This invention also provides a method for manufacturing a self-powered seismic detector based on the combination of triboelectric and magnetoelectric power, the specific steps of which are as follows:

[0020] (1) Machining the right cover and left cover of the seismic detector housing: using aluminum alloy material, designing the parameters of the right cover and left cover of the seismic detector housing using 3D modeling software, and machining the right cover and left cover of the seismic detector housing using CNC technology.

[0021] (2) Processing the upper and lower copper Z-shaped spring bases: Cut 100um thick brass sheets into rectangular strips with a width of 5mm. Perform cold forming operation on the rectangular strips in a Z shape. During the processing, ensure that the horizontal part of the Z shape is 5mm x 5mm and the angle between the inclined part and the horizontal part is arctan(1 / 2) to form a Z-shaped spring. Next, perform stress-relief annealing on the formed Z-shaped spring to eliminate the stress generated by the copper sheet during cold processing and stabilize the shape. Manually correct the Z-shaped spring after stress-relief annealing to ensure that the shape parameters meet the design requirements. Perform stress-relief annealing operation again to fix the shape. Finally, perform chamfering and upper and lower surface grinding operations on the upper and lower copper Z-shaped spring bases to enable the upper and lower copper Z-shaped spring bases to better bond with the assembly.

[0022] (3) Apply flux to the horizontal part above the upper copper Z-shaped spring base, and use solder wire to solder the upper signal transmission line to the surface of the horizontal part above the upper copper Z-shaped spring base. Apply flux to the horizontal part below the lower copper Z-shaped spring base, and use solder wire to solder the lower signal transmission line to the surface of the horizontal part below the lower copper Z-shaped spring base.

[0023] (4) Processing PDMS friction pads: Prepare a silicon mold with a groove 4.5 mm long, 4 mm wide, and 0.2 mm deep. The bottom surface of the silicon mold has evenly distributed spherical grooves with a radius of 0.1 mm. The top surface of the silicon mold has concave limiting holes 5.5 mm long, 5 mm wide, and 0.1 mm deep. Prepare a silicon mold cover plate 5.5 mm long and 5 mm wide. A boss 3.5 mm long, 3 mm wide, and 0.1 mm deep is machined at the center of the cover plate. Pour PDMS liquid prepolymer into the silicon mold. [The text abruptly ends here, likely due to an incomplete sentence or missing information.] Cover the silicon mold with a cover plate, ensuring that the edge of the cover plate is embedded in the concave limiting hole on the top surface of the silicon mold. Place a 50g weight on top of the cover plate to squeeze out the excess PDMS liquid prepolymer from the silicon mold. Place the silicon mold, the cover plate, and the 50g weight into a vacuum heating and drying oven to perform thermosetting of the PDMS liquid prepolymer. At the same time, the vacuum environment can eliminate air bubbles in the PDMS liquid mixture, ultimately forming a PDMS friction pad with a PDMS friction pad bump layer, a PDMS friction pad bottom border, and a PDMS friction pad bottom cavity.

[0024] (5) Processing N-type magnet mass block: A cylindrical column with a wall thickness of 1.5mm, a bottom radius of 2.5mm, and a height of 7mm is made by bonding neodymium iron boron material. The column is magnetized by multi-pole magnetization. After the outer and inner circumferences of the cylindrical column are magnetized by single poles, an N-type magnet mass block with an N pole on the outer circumference and an S pole on the inner circumference is formed.

[0025] (6) Processing N-type magnet rings: A cylindrical column with a wall thickness of 4.5 mm, a bottom radius of 4.25 mm, and a height of 5 mm is made by bonding neodymium iron boron material. The column is magnetized by multi-pole magnetization. After the outer and inner circumferences of the cylindrical column are magnetized by single poles, an N-type magnet ring with an S pole on the outer circumference and an N pole on the inner circumference is formed.

[0026] (7) Processing the induction coil: The brass wire with a radius of 0.1 mm is wound in a spiral along a cylindrical tube with a radius of 5.9 mm. The winding height is 5 mm. After the winding is completed, metal glue is applied to fix the coil. Leave a 5 mm long terminal at the top and bottom of the coil. Solder the two terminals of the coil to the positive and negative terminals of the power transmission line respectively.

[0027] (8) Embedded circuit board preparation: The circuit board structure and size parameters are designed by EDA software, and the circuit board is processed by the PCB manufacturing plant to form a disc-shaped embedded circuit board with an outer diameter of 15mm and an inner diameter of 9mm.

[0028] (9) Overall Assembly: After machining the above parts, fix the PDMS friction pads to the corresponding positions on the horizontal parts of the upper and lower copper Z-type spring bases, respectively. Install the induction coil in the inner ring of the N-type magnet ring. Insert the N-type magnet ring and the built-in circuit board into the corresponding semi-circular grooves on the right side cover of the seismic detector housing. Slide the built-in circuit board over the lower copper Z-type spring base. Insert and fix the lowest horizontal part of the lower copper Z-type spring base into the slot on the inner surface of the lower wall of the right side cover of the seismic detector housing. After passing the N-type magnet mass block through the induction coil, fix it in place. On the upper surface of the uppermost horizontal part of the lower copper Z-type spring base, the upper surface of the N-type magnet mass block is fixedly connected to the lower surface of the lowermost horizontal part of the upper copper Z-type spring base. The slot on the inner surface of the upper wall of the right cover of the seismic detector housing is inserted and fixed to the uppermost horizontal part of the upper copper Z-type spring base. The left cover of the seismic detector housing is connected to the right cover of the seismic detector housing. The uppermost horizontal part of the upper copper Z-type spring base is inserted and fixed to the slot on the inner surface of the upper wall of the left cover of the seismic detector housing. The lowermost horizontal part of the lower copper Z-type spring base is inserted and fixed to the slot on the inner surface of the lower wall of the left cover of the seismic detector housing.

[0029] Compared with existing technologies, the self-powered seismic detector based on the combination of triboelectric and magnetoelectric power provided by this invention has the following advantages:

[0030] (1) A combination of triboelectric and magnetoelectric sensing units is used, with both types sharing an N-type magnet mass block. The N-type magnet ring in the magnetoelectric sensing unit magnetically constrains the X and Y axis translation and rotation of the N-type magnet mass block. The triboelectric sensing unit constrains the Z-axis rotation of the N-type magnet mass block via a copper Z-type spring base and restricts its Z-axis translation. This structural design uses fewer assembly parts, is structurally stable, and has low resistance to Z-axis movement of the mass block. Seismic detectors equipped with this combined sensing unit exhibit strong shock resistance, light weight, low lateral sensitivity, and low spurious signal energy in the output signal.

[0031] (2) The combination of triboelectric and magnetoelectric sensing elements enables the seismic detector to achieve true self-powering and long-term operation, facilitating long-term seismic data acquisition in the field. The magnetoelectric sensing element, characterized by a low resonant frequency but high output current, is used as a power-saving unit. It converts the mechanical energy contained in the vibration process into high-power electrical energy, which is then rectified and stored in a supercapacitor. The stored energy in the supercapacitor is then boosted to power the built-in circuitry of the seismic detector. The triboelectric sensing element can generate low-power (sub-milliwatt) electrical energy during the electromechanical conversion process, converting vibration signals into high-fidelity electrical signals without consuming electrical energy.

[0032] (3) The copper Z-shaped spring base of the triboelectric sensor adopts a Z-shaped structure design. During the compression and tension process caused by external vibration, the inclined surface of the copper Z-shaped spring remains in contact with the PDMS friction pad on the horizontal surface of the copper Z-shaped spring base. The contact area is proportional to the compression or tension deformation of the copper Z-shaped spring base. This structure ensures a high linear relationship between the output electrical signal and the amplitude of the external vibration signal, preventing nonlinear distortion caused by the step signal output of the triboelectric sensitive unit due to the separation of the friction pair.

[0033] (4) The positive and negative triboelectric materials used to construct the triboelectric sensitive unit are brass and PDMS, respectively. During the contact separation process, brass has a very weak electron-binding ability while PDMS has an extremely strong electron-binding ability. The triboelectric pair constructed from these two materials has a high output signal. At the same time, brass has excellent mechanical properties and good electrical conductivity. It is processed into a Z-shaped spring structure to serve as a substrate and connected to the signal transmission line as an electrode of the triboelectric sensitive unit.

[0034] (5) The bump layer of the PDMS friction pad increases the effective contact area with the inclined surface of the copper Z-shaped spring base, thereby increasing the charge change during the contact separation process of the friction pair, which in turn increases the voltage output under the same deformation and improves the sensitivity of the triboelectric sensing unit. The PDMS friction pad has a bottom cavity. When the inclined surface of the copper Z-shaped spring base separates from the friction pad, the bottom cavity enables the PDMS friction pad and the copper Z-shaped spring base to achieve electrical insulation, causing the positive and negative friction materials in the friction pair to retain opposite charges respectively.

[0035] (6) The single-electrode structure among the four friction pair structures is adopted. The copper Z-type spring base is used as the positive friction material in the friction pair and also as the electrode. The lead wire is convenient and the structure is simple and stable.

[0036] (7) Using bonded neodymium iron boron material, it is processed into cylindrical magnet mass blocks and cylindrical magnet rings respectively. The outer and inner circumferences of the cylindrical cylinders are unipolar magnetized, so that the outer circumference of the magnet mass block and the inner circumference of the cylindrical magnet ring have the same magnetic poles. The lateral movement of the mass block is constrained by repulsive magnetic force.

[0037] (8) The housing of the seismic detector is made of aluminum alloy, which has the characteristics of being lightweight, easy to process, having high mechanical strength, and good electromagnetic noise shielding effect.

[0038] (9) The seismic detector has a built-in wireless data acquisition circuit. This circuit is powered by the electrical energy generated by the magnetoelectric sensing unit, acquires the output signal of the triboelectric sensing unit, buffers the signal locally, and transmits it wirelessly to the remote receiving system. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the external structure of the self-powered seismic detector based on the combination of triboelectric and magnetoelectric power provided by the present invention.

[0040] Figure 2 This is a schematic diagram of the internal structure of the self-powered seismic detector based on the combination of triboelectric and magnetoelectric power provided by the present invention.

[0041] Figure 3 This is a schematic diagram of the top structure of the PDMS friction pad in this invention.

[0042] Figure 4 This is a schematic diagram of the bottom structure of the PDMS friction pad in this invention.

[0043] In the diagram: 1. Upper copper Z-shaped spring base; 2. Right side cover of the seismic detector housing; 3. N-type magnet ring; 4. Induction coil; 5. N-type magnet mass block; 6. Lower copper Z-shaped spring base; 7. Negative terminal of the signal transmission line; 8. PDMS friction pad; 9. Negative terminal of the power transmission line; 10. Positive terminal of the power transmission line; 11. Positive terminal of the signal transmission line; 12. Raised layer of the PDMS friction pad; 13. Bottom frame of the PDMS friction pad; 14. Bottom cavity of the PDMS friction pad; 15. Left side cover of the seismic detector housing; 16. Internal circuit board. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and specific examples. For example... Figure 2 As shown, this invention provides a self-powered seismic detector based on the combination of triboelectric and magnetoelectric power. The detector's sensing element consists of two vertically distributed parts: a triboelectric sensing element and a magnetoelectric sensing element, which share and jointly constrain an N-magnet mass block. The electrical energy collected by the magnetoelectric sensing element powers the wireless signal acquisition circuit of the triboelectric sensing element.

[0045] The self-powered seismic detector based on the combination of triboelectric and magnetoelectric power includes a right cover 2 of a hollow semi-cylindrical columnar seismic detector housing, a left cover 15 of a seismic detector housing, and triboelectric and magnetoelectric sensitive units that interact with each other in the hollow cylindrical columnar cavity composed of the right cover 2 and the left cover 15 of the seismic detector housing.

[0046] The triboelectric sensing unit includes an N-type magnet mass block 5 located inside the cavity of a hollow cylindrical column; a copper Z-type spring base 1, capable of elastic deformation, fixed between the upper end face of the N-type magnet mass block 5 and the upper wall of the hollow cylindrical column; a lower copper Z-type spring base 6, with the same structure as the upper copper Z-type spring base 1, capable of elastic deformation, fixed between the lower wall of the hollow cylindrical column of the N-type magnet mass block 5; a PDMS friction pad 8 located on the upper copper Z-type spring base 1 and the lower copper Z-type spring base 6, which contacts and rubs against the upper copper Z-type spring base 1 and the lower copper Z-type spring base 6; a positive signal lead 11 connected to the upper copper Z-type spring base 1; and a signal lead 11 connected to the lower copper Z-type spring base 6. The signal lead-out negative terminal 7, wherein the spring mass system composed of the N-type magnet mass block 5, the upper copper Z-type spring base 1, and the lower copper Z-type spring base 6 is used to convert the external vibration signal into the deformation of the upper copper Z-type spring base 1 and the lower copper Z-type spring base 6; in the triboelectric couple composed of the upper copper Z-type spring base 1, the lower copper Z-type spring base 6, and the PDMS friction pad 8, the upper copper Z-type spring base 1 and the lower copper Z-type spring base 6 serve as positive triboelectric materials, and the PDMS friction pad 8 serves as negative triboelectric material. The PDMS friction pad 8 includes a PDMS friction pad bump layer 12 for charge transfer during contact friction and a PDMS friction pad bottom cavity 14 for storing accumulated charge;

[0047] The magnetoelectric sensing unit includes an N-type magnet mass block 5, an induction coil 4, an N-type magnet ring 3, a positive power transmission line 10, and a negative power transmission line 9. Symmetrically arranged semi-circular grooves for inserting and fixing the N-type magnet ring 3 are located in the middle of the right side cover 2 and the middle of the left side cover of the seismic detector housing. The N-type magnet ring 3 is fixed in the semi-circular grooves in the middle of the right side cover 2 and the middle of the left side cover of the seismic detector housing, within the inner cavity of the ring. The induction coil 4 is fixed in the inner ring of the N-type magnet ring 3. The magnet mass block 5 is set inside the induction coil 4 and can move in a single axis inside the induction coil 4 under the action of the N-type magnet ring 3 and the induction coil 4. The terminals at both ends of the induction coil 4 are connected to the positive terminal 10 and the negative terminal 9 of the power transmission line, respectively. The positive terminal 11 and the negative terminal 7 of the signal lead in the triboelectric sensitive unit are connected to the built-in circuit board 16 in the inner cavity of the hollow cylindrical column. The terminals at both ends of the induction coil 4 in the magnetoelectric sensitive unit are connected to the built-in circuit board 16 through the positive terminal 10 and the negative terminal 9 of the power transmission line, respectively.

[0048] Both the upper copper Z-shaped spring base 1 and the lower copper Z-shaped spring base 6 are composed of three horizontal sections evenly spaced from top to bottom and two inclined sections connecting adjacent horizontal sections, forming a double-layer Z-shaped structure. A layer of PDMS friction pad 8 is fixedly installed on the lower surface of the uppermost horizontal section, the upper and lower surfaces of the middle horizontal section, and the upper surface of the lower horizontal section. The uppermost horizontal section of the upper copper Z-shaped spring base 1 is fixedly connected to the inner surface of the upper wall of the hollow cylindrical column. The lowermost horizontal section of the upper copper Z-shaped spring base 1 is fixedly connected to the upper end face of the N-type magnet mass block 5. The uppermost horizontal section of the lower copper Z-shaped spring base 6 is fixedly connected to the lower end face of the N-type magnet mass block 5. The lowermost horizontal section of the lower copper Z-shaped spring base 6 is fixedly connected to the inner surface of the lower wall of the hollow cylindrical column.

[0049] The PDMS friction pad 8 includes a bump layer 12 for charge transfer during contact friction and a bottom cavity 14 for storing accumulated charge. The PDMS friction pad frame 13 around the bottom cavity 14 is fixedly connected to the horizontal portion of the upper copper Z-shaped spring base 1 and the horizontal portion of the lower copper Z-shaped spring base 6.

[0050] The N-type magnet ring 3 installed in the cavity of the hollow cylindrical column is a ring structure made of bonded neodymium iron boron material. After the outer and inner circumferences of the N-type magnet ring 3 are unipolar magnetized, the outer circumference of the N-type magnet ring 3 has an S pole and the inner circumference has an N pole.

[0051] The outer periphery of the N-type magnet mass block 5 has an N pole and the inner periphery has an S pole, while the outer periphery of the N-type magnet ring 3 has an S pole and the inner periphery has an N pole.

[0052] The edge where the right cover 2 of the seismic detector housing meets the left cover 15 has two notches located above and below the N-type magnet ring 3, respectively. The edge where the left cover 15 meets the right cover 2 has two notches symmetrically positioned to match the notches on the right cover 2. When the right cover 2 and the left cover 15 are joined, the two notches on the right cover 2 and the two notches on the left cover 15 form two through-holes for wiring. The circuit board 16 is circular and surrounds the lower copper Z-shaped spring base 6. The middle of the right cover 2 and the middle of the left cover of the seismic detector housing have symmetrically arranged semi-circular grooves for inserting and fixing the built-in circuit board 16. The built-in circuit board 16 is fixed in the semi-circular groove in the middle of the right cover 2 and the middle of the left cover of the seismic detector housing. The positive terminal of the signal lead 11 and the positive terminal of the power transmission line 10 pass through the upper wiring through hole and enter through the lower wiring through hole and are connected to the built-in circuit board 16.

[0053] The inner surface of the upper wall of the right cover 2 and the inner surface of the upper wall of the left cover 15 of the seismic detector housing have symmetrically arranged slots for inserting and fixing the uppermost horizontal part of the upper copper Z-shaped spring base 1. The inner surface of the lower wall of the right cover 2 and the inner surface of the lower wall of the left cover 15 of the seismic detector housing have symmetrically arranged slots for inserting and fixing the lowermost horizontal part of the lower copper Z-shaped spring base 6. The uppermost horizontal part of the upper copper Z-shaped spring base 1 is inserted and fixed in the slots on the inner surface of the upper wall of the right cover 2 and the upper wall of the left cover 15 of the seismic detector housing. The lowermost horizontal part of the lower copper Z-shaped spring base 6 is inserted and fixed in the slots on the inner surface of the lower wall of the right cover 2 and the lower wall of the left cover 15 of the seismic detector housing.

[0054] In the above structure, the N-type magnet ring 3 in the magnetoelectric sensing unit constrains the horizontal translation and rotation of the N-type magnet mass block 5 through magnetic force. The copper Z-type spring bases 1 and 6 in the triboelectric sensing unit constrain the vertical rotation of the N-type mass block 5 through torsional stiffness and adhesive force. The upper copper Z-type spring base 1 and the lower copper Z-type spring base 6 restrict the vertical translation of the N-type mass block 5 through telescopic stiffness. When external vibrations act on the seismic detector housing, the N-type magnet mass block 5 undergoes vertical translation due to its own inertia. For the triboelectric sensitive unit, the movement of the N-type magnet mass block 5 causes the upper copper Z-shaped spring base 1 and the lower copper Z-shaped spring base 6 to undergo tensile and compressive deformation. The inclined surfaces of the upper copper Z-shaped spring base 1 and the lower copper Z-shaped spring base 6 move away from or closer to the horizontal plane, thereby changing the contact area between the upper copper Z-shaped spring base 1 and the lower copper Z-shaped spring base 6 and the PDMS friction pad 8. Through the contact separation of triboelectric materials, equal amounts of opposite charges linearly related to the vibration intensity will be generated on the upper copper Z-shaped spring base 1 and the lower copper Z-shaped spring base 6 and the PDMS friction pad 8. Since the bottom cavity 14 of the PDMS friction pad 8 hinders the charge exchange between the positive and negative triboelectric materials, a vibration-related voltage signal can be obtained by connecting the upper copper Z-shaped spring base 1 and the lower copper Z-shaped spring base 6 through signal transmission lines 7 and 11, respectively. For the magnetoelectric sensing unit, the movement of the N-type magnet mass block 5 will change the magnetic flux in the induction coil 4, thereby generating an electrical signal at both ends of the induction coil 4. The high-power (hundreds of milliwatts level) electrical energy generated by the magnetoelectric sensing unit can be collected by connecting the two terminals of the induction coil 4 to the energy harvesting module of the built-in circuit through the power transmission lines 9 and 10. The electrical energy can be boosted and converted to power the wireless signal acquisition module of the triboelectric sensing unit in the built-in circuit.

[0055] The present invention also provides a method for manufacturing a self-powered seismic detector based on the combination of triboelectric and magnetoelectricity, the specific steps of which are as follows.

[0056] (1) Machining the right side cover 2 and the left side cover 15 of the seismic detector housing: using aluminum alloy material, designing the parameters of the right side cover 2 and the left side cover 15 of the seismic detector housing through 3D modeling software, and machining the right side cover 2 and the left side cover 15 of the seismic detector housing using CNC technology.

[0057] (2) Processing the upper copper Z-shaped spring base 1 and the lower copper Z-shaped spring base 6: Cut a 100um thick brass sheet into a rectangular strip with a width of 5mm. Perform cold forming operation on the rectangular strip in a Z shape. During the processing, ensure that the size of the horizontal part of the Z shape is 5mm x 5mm and the angle between the inclined part and the horizontal part is arctan(1 / 2) to form a Z-shaped spring. Next, perform stress relief annealing on the formed Z-shaped spring to eliminate the stress generated by the copper sheet during cold processing and stabilize the shape. Manually correct the Z-shaped spring after stress relief annealing to ensure that the shape parameters meet the design requirements. Perform stress relief annealing operation again to fix the shape. Finally, perform chamfering and upper and lower surface grinding operations on the upper copper Z-shaped spring base 1 and the lower copper Z-shaped spring base 6 so that the upper copper Z-shaped spring base 1 and the lower copper Z-shaped spring base 6 can better bond with the assembly.

[0058] (3) Apply flux to the horizontal part above the upper copper Z-type spring base 1, and use solder wire to solder the upper signal transmission line 11 to the surface of the horizontal part above the upper copper Z-type spring base 1. Apply flux to the horizontal part below the lower copper Z-type spring base 6, and use solder wire to solder the lower signal transmission line 7 to the surface of the horizontal part below the lower copper Z-type spring base 6.

[0059] (4) Processing PDMS friction pad 8: Prepare a silicon mold with a groove of 4.5 mm in length, 4 mm in width, and 0.2 mm in depth. The bottom surface of the silicon mold has spherical grooves with a radius of 0.1 mm evenly distributed. The top surface of the silicon mold has a concave limiting hole with a length of 5.5 mm, a width of 5 mm, and a depth of 0.1 mm. Prepare a silicon mold cover plate with a length of 5.5 mm and a width of 5 mm. A boss with a length of 3.5 mm, a width of 3 mm, and a depth of 0.1 mm is processed at the center of the cover plate. Pour PDMS liquid prepolymer into the silicon mold and cover the top surface of the silicon mold with a silicon... A silicon mold cover plate is used to ensure that the edge of the silicon mold cover plate is embedded in the concave limiting hole on the top surface of the silicon mold. A 50g weight is placed on the silicon mold cover plate to extrude the excess PDMS liquid prepolymer from the silicon mold. The silicon mold, silicon mold cover plate and 50g weight are placed in a vacuum heating and drying oven to perform thermosetting of the PDMS liquid prepolymer. At the same time, the vacuum environment can eliminate air bubbles in the PDMS liquid mixture, and finally a PDMS friction pad 8 with a PDMS friction pad bump layer 12, a PDMS friction pad bottom border 13 and a PDMS friction pad bottom cavity 14 is formed.

[0060] The friction pad sensitive unit consists of an upper copper Z-shaped spring base 1, a lower copper Z-shaped spring base 6, and a PDMS friction pad 8. The top of the PDMS friction pad 8 is a bump layer 12, and the bottom of the PDMS friction pad consists of a bottom frame 13 and a bottom cavity 14.

[0061] (5) Processing N-type magnet mass block 5: A cylindrical column with a wall thickness of 1.5 mm, a bottom radius of 2.5 mm, and a height of 7 mm is made by bonding neodymium iron boron material. It is magnetized by multi-pole magnetization. After the outer and inner circumferences of the cylindrical column are magnetized by single poles, an N-type magnet mass block 5 with an N pole on the outer circumference and an S pole on the inner circumference is formed.

[0062] (6) Processing N-type magnet ring 3: A cylindrical column with a wall thickness of 4.5 mm, a bottom radius of 4.25 mm, and a height of 5 mm is made by bonding neodymium iron boron material. The column is magnetized by multi-pole magnetization. After the outer and inner circumferences of the cylindrical column are magnetized by single poles, an N-type magnet ring 3 with an S pole on the outer circumference and an N pole on the inner circumference is formed.

[0063] (7) Processing induction coil 4: The brass wire with a radius of 0.1 mm is wound in a spiral along a cylindrical tube with a radius of 5.9 mm. The winding height is 5 mm. After the winding is completed, metal glue is applied to fix the coil. A 5 mm long terminal is left at the top and bottom of the coil. Solder the two terminals of the coil to the positive terminal 10 and the negative terminal 9 of the power transmission line respectively.

[0064] The magnetoelectric sensing unit consists of an N-type magnet ring 3, an induction coil 4, and an N-type magnet mass block 5.

[0065] (8) Embedded circuit board preparation 16: The circuit board structure and size parameters are designed by EDA software, and the circuit board is processed by the PCB manufacturing plant to form a disc-shaped embedded circuit board 16 with an outer diameter of 15mm and an inner diameter of 9mm.

[0066] (9) Overall Assembly: After processing the above parts, fix the PDMS friction pad 8 to the corresponding positions of the horizontal part of the upper copper Z-type spring base 1 and the horizontal part of the lower copper Z-type spring base 6, respectively. Install the induction coil 4 in the inner ring of the N-type magnet ring 3. Insert the N-type magnet ring 3 and the built-in circuit board 16 into the corresponding semi-circular grooves of the right side cover 2 of the seismic detector housing, respectively. Sleeve the built-in circuit board 16 over the lower copper Z-type spring base 6. Insert and fix the lowest horizontal part of the lower copper Z-type spring base 6 into the slot on the inner surface of the lower wall of the right side cover 2 of the seismic detector housing. After passing the N-type magnet mass block 5 through the induction coil 4, fix it in place. On the upper surface of the uppermost horizontal part of the lower copper Z-type spring base 6, the upper surface of the N-type magnet mass block 5 is fixedly connected to the lower surface of the lowermost horizontal part of the upper copper Z-type spring base 1. The slot on the inner surface of the upper wall of the right cover 2 of the seismic detector housing is inserted and fixed to the uppermost horizontal part of the upper copper Z-type spring base 1. The left cover 15 of the seismic detector housing is connected to the right cover 2 of the seismic detector housing. The uppermost horizontal part of the upper copper Z-type spring base 1 is inserted and fixed to the slot on the inner surface of the upper wall of the left cover 15 of the seismic detector housing. The lowermost horizontal part of the lower copper Z-type spring base 6 is inserted and fixed to the slot on the inner surface of the lower wall of the left cover 15 of the seismic detector housing.

[0067] The self-powered seismic detector based on the combination of triboelectric and magnetoelectric power, prepared using the method provided in this invention, has the advantages of simple and stable structure, light weight, strong resistance to electromagnetic interference, high sensitivity, self-powered operation, and no need for external connecting cables. This facilitates deployment by seismic exploration field workers and long-term data acquisition. Furthermore, the self-powered seismic detector based on the combination of triboelectric and magnetoelectric power prepared using the method provided in this invention has a higher dynamic range, lower spurious frequency distortion, and a larger bandwidth, enabling it to better integrate with modern high dynamic range seismic data acquisition systems and acquire higher quality data.

Claims

1. A self-powered seismic detector based on the combination of triboelectric and magnetoelectric power, characterized in that, The seismic detector housing includes a hollow semi-cylindrical column structure, a right cover (2) of the outer shell, a left cover (15) of the outer shell, and a triboelectric sensitive unit and a magnetoelectric sensitive unit that interact with each other in the hollow cylindrical column structure composed of the right cover (2) and the left cover (15). The triboelectric sensing unit includes an N-type magnet mass block (5) located in the cavity of a hollow cylindrical column; a copper Z-type spring base (1) fixed between the upper end face of the N-type magnet mass block (5) and the upper wall of the hollow cylindrical column, capable of elastic deformation; a lower copper Z-type spring base (6) fixed between the lower wall of the hollow cylindrical column of the N-type magnet mass block (5) and having the same structure as the upper copper Z-type spring base (1), capable of elastic deformation; a PDMS friction pad (8) located on the upper copper Z-type spring base (1) and the lower copper Z-type spring base (6) and in contact with and rubs against the upper copper Z-type spring base (1) and the lower copper Z-type spring base (6); a positive terminal (11) of a signal lead connected to the upper copper Z-type spring base (1); and a signal lead connected to the lower copper Z-type spring base (6). The negative terminal of the lead wire (7) is provided. The spring mass system consisting of the N-type magnet mass block (5), the upper copper Z-type spring base (1), and the lower copper Z-type spring base (6) is used to convert the external vibration signal into the deformation of the upper copper Z-type spring base (1) and the lower copper Z-type spring base (6). In the triboelectric couple consisting of the upper copper Z-type spring base (1), the lower copper Z-type spring base (6), and the PDMS friction pad (8), the upper copper Z-type spring base (1) and the lower copper Z-type spring base (6) are positive triboelectric materials, and the PDMS friction pad (8) is negative triboelectric material. The PDMS friction pad (8) includes a PDMS friction pad bump layer (12) for charge transfer during contact friction and a PDMS friction pad bottom cavity (14) for storing accumulated charge. The magnetoelectric sensing unit includes an N-type magnet mass block (5), an induction coil (4), an N-type magnet ring (3), a positive power transmission line (10), and a negative power transmission line (9). Symmetrically arranged semi-circular grooves for inserting and fixing the N-type magnet ring (3) are located in the middle of the right side cover (2) and the middle of the left side cover of the seismic detector housing. The N-type magnet ring (3) is fixed in the semi-circular groove in the middle of the right side cover (2) and the middle of the left side cover of the seismic detector housing, in the middle of the inner cavity. The induction coil (4) is fixed in the inner ring of the N-type magnet ring (3). Block (5) is set inside the induction coil (4) and can move in a single axis inside the induction coil (4) under the action of the N-type magnet ring (3) and the induction coil (4). The terminals at both ends of the induction coil (4) are connected to the positive pole (10) and the negative pole (9) of the power transmission line, respectively. The positive pole (11) and the negative pole (7) of the signal lead in the triboelectric sensitive unit are connected to the built-in circuit board (16) in the inner cavity of the hollow cylindrical column. The terminals at both ends of the induction coil (4) in the magnetoelectric sensitive unit are connected to the built-in circuit board (16) through the positive pole (10) and the negative pole (9) of the power transmission line, respectively.

2. The self-powered seismic detector based on the combination of triboelectric and magnetoelectric power according to claim 1, characterized in that, The upper copper Z-shaped spring base (1) and the lower copper Z-shaped spring base (6) are both composed of three horizontal parts evenly spaced from top to bottom and two inclined parts connecting two adjacent horizontal parts, forming a double-layer Z-shaped structure. A layer of PDMS friction pad (8) is fixedly installed on the lower surface of the uppermost horizontal part, the upper and lower surfaces of the middle horizontal part, and the upper surface of the lower horizontal part. The uppermost horizontal part of the upper copper Z-shaped spring base (1) is fixedly connected to the inner surface of the upper wall of the hollow cylindrical column. The lowermost horizontal part of the upper copper Z-shaped spring base (1) is fixedly connected to the upper end face of the N-type magnet mass block (5). The uppermost horizontal part of the lower copper Z-shaped spring base (6) is fixedly connected to the lower end face of the N-type magnet mass block (5). The lowermost horizontal part of the lower copper Z-shaped spring base (6) is fixedly connected to the inner surface of the lower wall of the hollow cylindrical column.

3. The self-powered seismic detector based on the combination of triboelectric and magnetoelectric power according to claim 2, characterized in that, The PDMS friction pad (8) includes a bump layer (12) for charge transfer during contact friction and a bottom cavity (14) for storing accumulated charge. The PDMS friction pad frame (13) around the bottom cavity (14) is fixedly connected to the horizontal part of the upper copper Z-shaped spring base (1) and the horizontal part of the lower copper Z-shaped spring base (6).

4. The self-powered seismic detector based on the combination of triboelectric and magnetoelectric power according to claim 1, characterized in that, The N-type magnet ring (3) installed in the cavity of the hollow cylindrical cylinder is a ring structure made of bonded neodymium iron boron material. After the outer and inner circumferences of the N-type magnet ring (3) are unipolar magnetized, the outer circumference of the N-type magnet ring (3) has an S pole and the inner circumference has an N pole.

5. The self-powered seismic detector based on the combination of triboelectric and magnetoelectric power according to claim 4, characterized in that, The outer periphery of the N-type magnet mass block (5) has an N pole and the inner periphery has an S pole, and the outer periphery of the N-type magnet ring (3) has an S pole and the inner periphery has an N pole.

6. The self-powered seismic detector based on the combination of triboelectric and magnetoelectric power according to claim 1, characterized in that, The edge where the right cover (2) of the seismic detector housing meets the left cover (15) of the seismic detector housing has two notches located above and below the N-type magnet ring (3), respectively. The edge where the left cover (15) of the seismic detector housing meets the right cover (2) of the seismic detector housing has two notches symmetrically arranged with the notches on the right cover (2) of the seismic detector housing. After the right cover (2) of the seismic detector housing meets the left cover (15) of the seismic detector housing, the two notches on the right cover (2) and the two notches on the left cover (15) of the seismic detector housing form two wiring through holes. The built-in circuit board (16) is annular and surrounds the lower copper Z-shaped spring base (6). The middle of the right cover (2) and the middle of the left cover of the seismic detector housing have symmetrically arranged semi-circular grooves for inserting and fixing the built-in circuit board (16). The built-in circuit board (16) is fixed in the semi-circular groove in the middle of the right cover (2) and the middle of the left cover of the seismic detector housing. The positive terminal of the signal lead (11) and the positive terminal of the power transmission line (10) pass through the upper wiring through hole and enter through the lower wiring through hole and connect to the built-in circuit board (16).

7. The self-powered seismic detector based on the combination of triboelectric and magnetoelectric power according to claim 1, characterized in that, The inner surface of the upper wall of the right cover (2) of the seismic detector housing and the inner surface of the upper wall of the left cover (15) of the seismic detector housing have symmetrically arranged slots for inserting and fixing the uppermost horizontal part of the upper copper Z-type spring base (1). The inner surface of the lower wall of the right cover (2) of the seismic detector housing and the inner surface of the lower wall of the left cover (15) of the seismic detector housing have symmetrically arranged slots for inserting and fixing the lowermost horizontal part of the lower copper Z-type spring base (6). The uppermost horizontal part of the upper copper Z-type spring base (1) is inserted and fixed in the slots on the inner surface of the upper wall of the right cover (2) of the seismic detector housing and the slots on the inner surface of the upper wall of the left cover (15) of the seismic detector housing. The lowermost horizontal part of the lower copper Z-type spring base (6) is inserted and fixed in the slots on the inner surface of the lower wall of the right cover (2) of the seismic detector housing and the slots on the inner surface of the lower wall of the left cover (15) of the seismic detector housing.

8. A method for manufacturing a self-powered seismic detector based on the combination of triboelectricity and magnetoelectricity, used to manufacture the self-powered seismic detector based on the combination of triboelectricity and magnetoelectricity as described in claim 3, characterized in that, The specific steps are as follows: (1) Machining the right side cover (2) and the left side cover (15) of the seismic detector housing: Using aluminum alloy material, the parameters of the right side cover (2) and the left side cover (15) of the seismic detector housing are designed by 3D modeling software, and CNC technology is used to machine the right side cover (2) and the left side cover (15) of the seismic detector housing. (2) Processing the upper copper Z-shaped spring base (1) and the lower copper Z-shaped spring base (6): Cut a 100um thick brass sheet into a rectangular strip with a width of 5mm. Perform cold forming operation on the rectangular strip according to the Z shape. During the processing, ensure that the size of the horizontal part of the Z shape is 5mm x 5mm and the angle between the inclined part and the horizontal part is arctan(1 / 2) to form a Z-shaped spring. Next, perform stress relief annealing on the formed Z-shaped spring to eliminate the stress generated by the copper sheet during the cold processing and stabilize the shape. Perform manual correction on the Z-shaped spring after stress relief annealing to ensure that the shape parameters meet the design requirements. Perform stress relief annealing operation again to fix the shape. Finally, perform chamfering and upper and lower surface grinding operations on the upper copper Z-shaped spring base (1) and the lower copper Z-shaped spring base (6) so that the upper copper Z-shaped spring base (1) and the lower copper Z-shaped spring base (6) can be better bonded to the assembly. (3) Apply flux to the horizontal part above the upper copper Z-type spring base (1), and use solder wire to solder the upper signal transmission line (11) to the surface of the horizontal part above the upper copper Z-type spring base (1). Apply flux to the horizontal part below the lower copper Z-type spring base (6), and use solder wire to solder the lower signal transmission line (7) to the surface of the horizontal part below the lower copper Z-type spring base (6). (4) Processing PDMS friction pad (8): Prepare a silicon mold with a groove of 4.5 mm in length, 4 mm in width, and 0.2 mm in depth. The bottom surface of the silicon mold has spherical grooves with a radius of 0.1 mm evenly distributed. The top surface of the silicon mold has a concave limiting hole with a length of 5.5 mm, a width of 5 mm, and a depth of 0.1 mm. Prepare a silicon mold cover plate with a length of 5.5 mm and a width of 5 mm. A boss with a length of 3.5 mm, a width of 3 mm, and a depth of 0.1 mm is processed at the center of the cover plate. Pour PDMS liquid prepolymer into the silicon mold. Cover the top surface of the silicon mold with the silicon mold. Cover plate, ensuring that the edge of the silicon mold cover plate is embedded in the concave limiting hole on the top surface of the silicon mold, place a 50g weight on the top of the silicon mold cover plate, squeeze out the excess PDMS liquid prepolymer in the silicon mold, put the silicon mold, silicon mold cover plate and 50g weight into a vacuum heating drying oven to perform thermosetting operation on the PDMS liquid prepolymer. At the same time, the vacuum environment can eliminate the air bubbles in the PDMS liquid mixture, and finally form a PDMS friction pad (8) with a PDMS friction pad bump layer (12), a PDMS friction pad bottom frame (13) and a PDMS friction pad bottom cavity (14); (5) Processing N-type magnet mass block (5): A cylindrical column with a wall thickness of 1.5 mm, a bottom radius of 2.5 mm, and a height of 7 mm is made by bonding neodymium iron boron material. The column is magnetized by multi-pole magnetization. After the outer and inner circumferences of the cylindrical column are magnetized by single poles, an N-type magnet mass block with an N pole on the outer circumference and an S pole on the inner circumference is formed (5). (6) Processing N-type magnet ring (3): A cylindrical column with a wall thickness of 4.5 mm, a bottom radius of 4.25 mm, and a height of 5 mm is made by bonding neodymium iron boron material. The column is magnetized by multi-pole magnetization. After the outer and inner circumferences of the cylindrical column are magnetized by single poles, an N-type magnet ring with an S pole on the outer circumference and an N pole on the inner circumference is formed (3). (7) Processing the induction coil (4): The brass wire with a radius of 0.1 mm is spirally wound along a cylindrical tube with a radius of 5.9 mm. The winding height is 5 mm. After the winding is completed, metal glue is applied to fix the coil. A 5 mm long terminal is left at the top and bottom of the coil. Solder is used to solder the two terminals of the coil to the positive terminal (10) and the negative terminal (9) of the power transmission line respectively. (8) Embedded circuit board preparation (16): The circuit board structure and size parameters are designed by EDA software, and the circuit board is processed by the PCB manufacturing plant to form a disc-shaped embedded circuit board with an outer diameter of 15mm and an inner diameter of 9mm (16). (9) Overall Assembly: After processing the above parts, fix the PDMS friction pad (8) to the corresponding positions of the horizontal part of the upper copper Z-type spring base (1) and the horizontal part of the lower copper Z-type spring base (6), respectively. Install the induction coil (4) in the inner ring of the N-type magnet ring (3). Insert the N-type magnet ring (3) and the built-in circuit board (16) into the corresponding semi-circular grooves of the right side cover (2) of the seismic detector housing, respectively. Sleeve the built-in circuit board (16) around the lower copper Z-type spring base (6). Insert and fix the lowest horizontal part of the lower copper Z-type spring base (6) into the slot on the inner surface of the lower wall of the right side cover (2) of the seismic detector housing. After passing the N-type magnet mass block (5) through the induction coil (4), fix it. The upper surface of the uppermost horizontal part of the lower copper Z-type spring base (6) is fixedly installed on the upper surface of the uppermost horizontal part of the upper copper Z-type spring base (1). The upper surface of the slot on the inner surface of the upper wall of the right cover (2) of the seismic detector housing is inserted and fixed to the uppermost horizontal part of the upper copper Z-type spring base (1). The left cover (15) of the seismic detector housing is connected to the right cover (2) of the seismic detector housing. The uppermost horizontal part of the upper copper Z-type spring base (1) is inserted and fixed to the slot on the inner surface of the upper wall of the left cover (15) of the seismic detector housing. The lowermost horizontal part of the lower copper Z-type spring base (6) is inserted and fixed to the slot on the inner surface of the lower wall of the left cover (15) of the seismic detector housing.

Images