Composite magnetic field energy recovery device based on magneto-force-electric coupling and current mutual inductance and preparation method thereof

Abstract

The present invention proposes a composite magnetic field energy recovery device based on magneto-electric coupling and current mutual inductance and a preparation method thereof, which belongs to the field of magnetic field energy capture technology. It solves the application needs of existing power grid self-powered sensors and the problems of existing magnetic field energy extraction technology. Piezoelectric material is pasted on the surface of the magnetostrictive beam, one end of the magnetostrictive beam is fixed on the packaging shell, and a permanent magnet is placed on the other free end. The permanent magnet is set at the center position of the air gap of the magnetic core, and a mutual inductance coil is spirally wound on one side of the magnetic core. The present invention takes into account the magnetic field effect of the non-closed iron core, increases the saturation current of the current mutual inductance coil, and combines the respective advantages of the current mutual inductance coil and the magneto-electric energy recovery device. The characteristic of the magneto-electric energy recovery device that the output voltage is large under small current is used to solve the problem of the large working threshold current of the traditional current mutual inductance coil; on the other hand, the advantage of the current mutual inductance coil having high output power under large current is used to effectively store electricity under large current.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic field energy capture, and in particular relates to a composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual inductance and a preparation method thereof. Background Art

[0002] The vast number of sensor communication nodes in power distribution networks is the foundation for online fault monitoring of transmission lines and information interconnection, making it crucial for building smart grids. However, current sensor networks still face the bottleneck of energy supply. Installing and using traditional chemical batteries in transmission lines has limitations such as limited service life, difficulty in maintenance and replacement, and environmental pollution.

[0003] Energy-harvesting coils based on the principle of current mutual induction have low manufacturing costs and relatively mature technology, making them the best choice for self-powered sensor networks in the current power grid. However, current mutual induction coils require a toroidal magnetic core, which is often large and difficult to install in space-constrained distribution lines. In addition, when the high-voltage bus current is too low (<2A), the output voltage is only on the millivolt level, resulting in a power supply dead zone. Excessive high-voltage bus current can also cause the closed core to saturate and rapidly heat up. To resolve this contradiction, a non-closed core is generally used for magnetic concentration. The introduction of an air gap improves the saturation problem, but does not address the low output voltage of the induction coil at low currents.

[0004] Compared with current transformers, piezoelectric energy harvesters can effectively solve the above-mentioned power supply dead zone problem under low current because of their large internal resistance and high electromechanical conversion efficiency at low frequencies. The magnetic-mechanical-electrical energy harvester is an extension of the piezoelectric energy harvester. It realizes magnetic-mechanical conversion through magnetic torque effect and magnetostrictive effect, and then uses piezoelectric effect for electromechanical conversion, thereby realizing the function of energy collection. The magnetic-mechanical-electrical energy harvester can achieve up to 150uW / (cm2) without the assistance of a magnetic focusing ring. 3 *Oe 2 ) and an open-circuit output voltage of 42Vpp (@0.48Oe, 50Hz magnetic field excitation). However, similar to traditional current transformer coils, magnetic-mechanical-electric energy harvesters struggle to withstand high current excitation, so open-loop configurations are often used to increase the upper limit of saturation operating current. Furthermore, piezoelectric energy harvesters have limited output power, only in the milliwatt range, far below the power levels of current transformers. Summary of the Invention

[0005] In view of this, the present invention aims to propose a composite magnetic field energy recovery device based on magnetic-mechanical-electric coupling and current mutual inductance to solve the application requirements of the existing grid self-powered sensors mentioned in the above background technology and the problems existing in the existing magnetic field energy harvesting technology.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions: a composite magnetic field energy recovery device based on magnetic-mechanical-electric coupling and current mutual induction, comprising a packaging shell, a current-carrying conductor, two pairs of V-shaped clamps, bolts, a mutual induction coil, a magnetic core, a piezoelectric material, a magnetostrictive beam, and a permanent magnet;

[0007] The piezoelectric material is adhered to the surface of the magnetostrictive beam. One end of the magnetostrictive beam is tightened and fixed to the packaging shell by a clamping bolt. A permanent magnet is placed at the other free end. The permanent magnet is set at the center position of the air gap of the magnetostrictive core. A limit device is set inside the packaging shell to fix the magnetostrictive core. A mutual inductance coil is spirally wound on one side of the magnetostrictive core. The current-carrying wire is fixed to the packaging shell by a V-shaped clamp and bolts at both ends.

[0008] Furthermore, the piezoelectric material is a piezoelectric ceramic, a piezoelectric single crystal, or a piezoelectric polymer, and may be one of PVDF, PVDF-TrFE, LiNbO3, BaTiO3, Pb(Zr,Ti)O3, Pb(Mg,Nb)O3-PbTiO3, Pb(Zn,Nb)O3-PbTiO3, or BiScO3-PbTiO3.

[0009] Furthermore, the magnetostrictive beam is made of a single magnetostrictive material, including one of Metglas, Fe-Ga alloy, Terfernol-D alloy, Fe-Ni alloy, FeCo, FeCoB, FeGaB, NiZn ferrite and Ni metal, or is a composite of a magnetostrictive material and an elastic metal layer, and the elastic metal includes one of stainless steel, spring steel, copper, and alloy copper.

[0010] Furthermore, the mutual inductance coil is tightly wound around the magnetic core with surface insulation of copper wire. The magnetic core is open-loop configured, and the air gap space is sufficient to accommodate the permanent magnet mass block in the magnetic-mechanical-electrical energy recovery device.

[0011] Furthermore, a force buffer device is added to the surface of the air gap to limit the displacement of the free end of the cantilever beam and prevent the impact force from damaging the structure. The magnetic core is designed to be either circular or U-shaped.

[0012] Furthermore, the permanent magnet is cylindrical or rectangular, and is placed near the free end or at the middle node of the magnetostrictive beam 10. The permanent magnet includes one of NdFeB, SmCo, AlNiCo and permanent ferrite.

[0013] A method for preparing a composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction specifically comprises the following steps:

[0014] (1) Mechanical design, 3D printing and processing of packaging shell;

[0015] (2) Wind the mutual inductance coil evenly on the magnetic core;

[0016] (3) The magnetic core wound with the coil is fixedly installed in the packaging shell;

[0017] (4) Preparation of piezoelectric materials, magnetostrictive materials and completion of two-phase material composites;

[0018] (5) Fix the package shell to the current-carrying wire through a V-shaped clamp;

[0019] (6) A permanent magnet is placed at the free end of the magnetostrictive beam, and the other end is fixed to the packaging shell by bolts, while the permanent magnet is located at the center of the air gap of the magnetostrictive core;

[0020] Furthermore, the preparation method of the magnetostrictive material in step (4) is: cutting the magnetostrictive material into a target size, wiping the surface with alcohol, and removing it after drying; spin-coating epoxy resin on the surface of the magnetostrictive material to complete the composite of multiple layers of magnetostrictive material; placing the multi-layer magnetostrictive material in a static press and curing it at room temperature for 24 hours and removing it.

[0021] Furthermore, the piezoelectric material in step (4) is a bulk material or a macroscopic fiber material. The bulk piezoelectric material is polarized by thickness, and the macroscopic piezoelectric fiber is transversely polarized by interdigitated electrodes or parallel thickness polarization to reduce internal resistance.

[0022] The preparation method of macroscopic piezoelectric fiber is as follows: make flexible interdigital electrodes with a thickness of 40um; ultrasonically clean the thickness-polarized piezoelectric fibers and take them out after drying; spin-coat epoxy resin on the surface of the flexible interdigital electrodes, and place the piezoelectric fibers in sequence to complete the composite of the piezoelectric fibers and the flexible electrodes.

[0023] Furthermore, the preparation method of the two-phase composite of piezoelectric material and magnetostrictive material in step (4) is as follows: the piezoelectric fiber of the composite flexible electrode is cured at room temperature for 24 hours using vacuum compression technology and then removed to form a piezoelectric macro fiber composite material (MFC); epoxy resin is spin-coated on the surface of the piezoelectric macro fiber composite material (MFC) and the magnetostrictive beam to bond the two parts, and the two parts are removed after curing.

[0024] Compared with the prior art, the composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual inductance and the preparation method thereof described in the present invention have the following beneficial effects:

[0025] The composite magnetic field energy recovery device based on magnetic-mechanical-electric coupling and current mutual inductance proposed in the present invention takes into account the magnetic field concentration effect of the non-closed iron core and combines the respective advantages of the current mutual inductance coil and the magnetic-mechanical-electric energy recovery device. On the one hand, it greatly increases the saturation current of the current mutual inductance coil. Secondly, it utilizes the characteristic of the magnetic-mechanical-electric energy recovery device that the output voltage is large under small current, effectively solving the problem of the large working threshold current of the traditional current mutual inductance coil; on the other hand, it utilizes the advantage of the current mutual inductance coil that the output power is high under large current, and also ensures that the composite energy harvesting device can not only supply power normally under small current, but also effectively store electricity under large current. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 This is a schematic diagram of the overall structure of a composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual inductance according to the present invention;

[0028] Figure 2 This is a schematic diagram of the internal structure of a composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual inductance described in the present invention.

[0029] Among them, 1- packaging shell; 2- fixing bolts / nuts; 3- current-carrying wire; 4- V-shaped clamp; 5- bolt; 6- mutual inductance coil; 7- magnetic core; 8- clamping bolt; 9- piezoelectric material; 10- magnetostrictive beam; 11- pre-set opening; 12- permanent magnet. DETAILED DESCRIPTION

[0030] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features therein can be combined with each other in the absence of conflict, and the embodiments described are only part of the embodiments of the present invention, not all of the embodiments.

[0031] 1. Specific implementation method 1, see Figure 1-2 This embodiment describes a composite magnetic field energy recovery device based on magnetic-mechanical-electric coupling and current mutual induction, comprising a packaging shell 1, a current-carrying conductor 3, two pairs of V-shaped clamps 4, a bolt 5, a mutual induction coil 6, a magnetic core 7, a piezoelectric material 9, a magnetostrictive beam 10, and a permanent magnet 12.

[0032] The piezoelectric material 9 is adhered to the surface of the magnetostrictive beam 10. One end of the magnetostrictive beam 10 is tightened and fixed to the packaging shell 1 by a clamping bolt 8. A permanent magnet 12 is placed on the other free end. The permanent magnet 12 is set at the center position of the air gap of the magnet core 7. A limit device is set inside the packaging shell 1 to fix the magnet core 7. A mutual inductance coil 6 is spirally wound on one side of the magnet core 7. The current-carrying wire 3 is fixed to the packaging shell 1 by the cooperation of a V-shaped clamp 4 and bolts 5 at both ends.

[0033] The piezoelectric material 9 is a piezoelectric ceramic, a piezoelectric single crystal, or a piezoelectric polymer, and may be one of PVDF, PVDF-TrFE, LiNbO3, BaTiO3, Pb(Zr,Ti)O3, Pb(Mg,Nb)O3-PbTiO3, Pb(Zn,Nb)O3-PbTiO3, or BiScO3-PbTiO3.

[0034] The magnetostrictive beam 10 is made of a single magnetostrictive material, including one of Metglas, Fe-Ga alloy, Terfernol-D alloy, Fe-Ni alloy, FeCo, FeCoB, FeGaB, NiZn ferrite and Ni metal, or is composed of a composite of a magnetostrictive material and an elastic metal layer, the elastic metal including one of stainless steel, spring steel, copper, and alloy copper. The magnetic mass block at the free end is a permanent magnet, including one of NdFeB, SmCo, AlNiCo and permanent ferrite.

[0035] The mutual inductance coil 6 is tightly wound around the magnetic core 7 using surface-insulated copper wire. The magnetic core 7 is open-loop, and the air gap space is sufficient to accommodate the permanent magnet 12.

[0036] A force buffer device is added to the surface of the air gap to limit the displacement of the free end of the magnetostrictive beam 10 and prevent the impact force from damaging the structure. The magnetic core 7 is designed to be circular or U-shaped.

[0037] The permanent magnet 12 is cylindrical or rectangular and is placed near the free end or at an intermediate node of the magnetostrictive beam 10 .

[0038] The packaging shell 1 is divided into two parts, and the two parts of the packaging shell 1 are connected and fixed together by a pair of upper and lower bolts 2.

[0039] The V-shaped clamps at both ends of the packaging shell 1 are connected to the bolts 5 that match them through the light holes. The bolts 5 are rotated to adjust the clamping radius of the V-shaped clamp 4 to achieve the fixation of wires with different diameters.

[0040] Through the opening on the packaging shell 1, tighten the bolt 8 to fix the clamping end of the cantilever beam magnetic-mechanical-electrical energy recovery device.

[0041] The piezoelectric material 9 and magnetostrictive beam 10 in the cantilever beam magneto-mechanical-electric energy harvester are bonded together with epoxy resin. The permanent magnet 12 at the free end is magnetized perpendicular to the magnetic field in the air gap of the magnetic core 7, generating torque.

[0042] The magnetostrictive beam 10 in the magnetic-mechanical-electrical energy recovery device can have a rectangular, triangular, trapezoidal, or any combination thereof. Clamping methods include either single-end or double-end clamping. The permanent magnet 12 can be cylindrical or rectangular and placed near the free end of the beam or at an intermediate node.

[0043] The current transformer consists of an open-loop magnet core 7 and a mutual inductance coil 6. The magnetic-mechanical-electrical energy harvester adopts a classic cantilever beam structure, including a piezoelectric material 9, a magnetostrictive beam 10, and a permanent magnet 12. The piezoelectric material 9 is adhered to the surface of the magnetostrictive beam 10 with epoxy resin; one end of the magnetostrictive beam 10 is tightened and fixed in the packaging shell 1 by nuts / bolts, and a permanent magnet 12 is placed at the free end to achieve a preset resonant frequency; the permanent magnet 12 is placed in the center of the air gap of the magnet core 7. The magnet core 7 is a high-permeability ferrite, with a mutual inductance coil 6 spirally wound on one side. The current-carrying wire 3 is fixed to the packaging shell 1 by a V-shaped clamp 4 and bolts at both ends. A groove is provided on the inner side of the packaging shell 1 to accommodate the mutual inductance coil, and an opening is provided to tighten the clamping end of the magnetostrictive beam 10.

[0044] In this embodiment, the mutual inductance coil is tightly wound with 350 μm diameter copper enameled wire, a single layer with 100 turns. The magnetic core is made of iron-nickel oxide with a relative magnetic permeability of 4000. It is a rectangular parallelepiped structure with outer dimensions of 60 mm long, 80 mm wide, and 10 mm thick, and inner dimensions of 40 mm long, 60 mm wide, and 10 mm thick, with a hollow center. The four outer corners are rounded with a radius of 15 mm, the inner corners are rounded with a radius of 5 mm, and the air gap is 30 mm long. The magnetostrictive beam is composed of multiple layers of magnetostrictive material Metglas, measuring 45 mm long, 7 mm wide, and 0.6 mm thick. The Metglas layers are composited with epoxy resin. The piezoelectric material is a flexible macrofiber material (MFC), measuring 40 mm long, 14 mm wide, and 0.23 mm thick. The MFC is composed of piezoelectric ceramic PZT, flexible electrodes, and epoxy resin. The piezoelectric material and magnetostrictive beam are bonded together with epoxy resin; the coil wrapped around the magnetic core is secured with 502 glue. The permanent magnet mass is a rectangular parallelepiped with overall dimensions of 19 mm long, 5 mm wide, and 9 mm high. It is made of the strong magnet NdFeB. The packaging housing 1 is manufactured using 3D printing technology.

[0045] In the implementation case, a method for preparing a composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction includes the following steps:

[0046] Step 1: Mechanical design and 3D printing of the packaging shell 1.

[0047] Step 2: Evenly wind the mutual inductance coil 6 on the magnetic core 7.

[0048] Step 3: Fix the magnetic core 7 wound with the coil on the packaging shell 1.

[0049] Step 4: Cut the magnetostrictive material Metglas into target size, wipe the surface with alcohol, and take it out after drying.

[0050] Step 5: Spin-coat epoxy resin (West System 105 / 206) on the surface of the magnetostrictive material to complete the composite of multiple layers of magnetostrictive material.

[0051] Step 6: Place the multi-layer magnetostrictive material into a static press and cure at room temperature for 24 hours before taking it out.

[0052] Step 7: Make flexible interdigital electrodes with a thickness of 40 μm.

[0053] Step 8: ultrasonically clean the thickness-polarized piezoelectric fiber, and take it out after drying.

[0054] Step 9: Spin-coat epoxy resin on the surface of the flexible interdigitated electrode and sequentially place the piezoelectric fiber material to complete the composite of the piezoelectric material and the flexible electrode.

[0055] Step 10: The piezoelectric fibers of the composite flexible electrode are cured at room temperature for 24 hours using vacuum compression technology and then taken out to form a piezoelectric macro fiber material MFC.

[0056] Step 11: Spin-coat epoxy resin (WestSystem105 / 206) on the surface of the piezoelectric macro fiber material MFC and the magnetostrictive beam to bond the two parts. After curing, remove the parts.

[0057] Step 12: Place a permanent magnet NdFeB 12 on the free end of the magnetostrictive beam 10, and fix the other end to the packaging shell 1 with bolts, while making the permanent magnet 12 located in the middle of the iron core air gap.

[0058] Step 13: The bolt 5 is matched with the V-shaped clamp 4 and tightened inward until the current-carrying wire 3 is fixed.

[0059] The composite magnetic field energy harvester based on magnetic-mechanical-electric coupling and current mutual inductance proposed in this invention takes into account the magnetic field effect of the non-closed iron core and combines the respective advantages of the current mutual inductance coil and the magnetic-mechanical-electric energy harvester. On the one hand, it greatly increases the saturation current of the current mutual inductance coil. Secondly, it takes advantage of the high output voltage of the magnetic-mechanical-electric energy harvester at low currents to effectively solve the problem of high operating threshold current of traditional current mutual inductance coils. On the other hand, the advantage of the current mutual inductance coil's high output power at high currents ensures that the composite energy harvesting device can both normally supply power at low currents and effectively store electricity at high currents.

[0060] The embodiments of the present invention disclosed above are intended only to illustrate the present invention. The embodiments do not describe all details in detail, nor do they limit the present invention to the specific embodiments described. Numerous modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention.

Claims

1. A composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual inductance, characterized by: It comprises a packaging shell (1), a current-carrying wire (3), two pairs of V-shaped clamps (4), bolts (5), a mutual inductance coil (6), a magnetic core (7), a piezoelectric material (9), a magnetostrictive beam (10) and a permanent magnet (12); The piezoelectric material (9) is adhered to the surface of the magnetostrictive beam (10); one end of the magnetostrictive beam (10) is tightened and fixed to the packaging shell (1) by a clamping bolt (8); a permanent magnet (12) is placed on the other free end; the permanent magnet (12) is arranged at the center position of the air gap of the magnetostrictive core (7); a limiting device is provided inside the packaging shell (1) for fixing the magnetostrictive core (7); a mutual inductance coil (6) is wound around one side of the magnetostrictive core (7); a current-carrying wire (3) is fixed to the packaging shell (1) by the cooperation of a V-shaped clamp (4) and bolts (5) at both ends; the magnetostrictive core (7) is open-loop configured, and the air gap space is sufficient to accommodate the permanent magnet (12).

2. The hybrid magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction according to claim 1 is characterized in that: The piezoelectric material (9) is a piezoelectric ceramic, a piezoelectric single crystal, or a piezoelectric polymer, and can be one of PVDF, PVDF-TrFE, LiNbO3, BaTiO3, Pb(Zr, Ti)O3, Pb(Mg, Nb)O3-PbTiO3, Pb(Zn, Nb)O3-PbTiO3, or BiScO3-PbTiO3.

3. The hybrid magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction according to claim 1 is characterized in that: The magnetostrictive beam (10) is made of a single magnetostrictive material, including one of Metglas, Fe-Ga alloy, Terfernol-D alloy, Fe-Ni alloy, FeCo, FeCoB, FeGaB, NiZn ferrite and Ni metal, or is composited with a magnetostrictive material and an elastic metal layer, and the elastic metal includes one of stainless steel, spring steel, copper and alloy copper.

4. The hybrid magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction according to claim 1 is characterized in that: The mutual inductance coil (6) is tightly wound around a magnetic core using surface-insulated copper wire.

5. The hybrid magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction according to claim 4 is characterized in that: A force buffer device is added to the surface of the air gap to limit the displacement of the free end of the magnetostrictive beam (10) and prevent the impact force from damaging the structure. The magnetic core (7) is designed to be circular or U-shaped.

6. The hybrid magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction according to claim 1 is characterized in that: The permanent magnet (12) is cylindrical or rectangular and is placed near the free end or at an intermediate node of the magnetostrictive beam (10). The permanent magnet (12) comprises one of NdFeB, SmCo, AlNiCo and permanent ferrite.

7. A method for preparing a composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction according to claim 1, characterized in that: The specific steps include: (1) Mechanical design, 3D printing and processing of packaging shell (1); (2) uniformly winding the mutual inductance coil (6) on the magnetic core (7); (3) The magnetic core (7) wound with the coil is fixedly installed in the packaging shell (1); (4) preparing piezoelectric material (9), magnetostrictive material and completing the two-phase material composite; (5) The packaging shell (1) is fixedly connected to the current-carrying wire (3) through a V-shaped clamp (4); (6) A permanent magnet (12) is placed on the free end of the magnetostrictive beam (10), and the other end is fixed to the packaging shell (1) by bolts, and the permanent magnet (12) is located at the center of the air gap of the magnet core (7); 8. The method for preparing a composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction according to claim 7, characterized in that: The preparation method of the magnetostrictive material in step (4) is as follows: cutting the magnetostrictive material into a target size, wiping the surface with alcohol, and removing it after drying; spin-coating epoxy resin on the surface of the magnetostrictive material to complete the composite of multiple layers of magnetostrictive material; placing the multiple layers of magnetostrictive material in a static press and curing them at room temperature for 24 hours before removing them.

9. The method for preparing a composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction according to claim 7, characterized in that: The piezoelectric material (9) in step (4) is a bulk material or a macroscopic fiber material. The bulk piezoelectric material is polarized by thickness, and the macroscopic piezoelectric fiber is transversely polarized by interdigitated electrodes or parallel thickness polarization to reduce internal resistance. The preparation method of macroscopic piezoelectric fiber is as follows: making flexible interdigital electrodes with a thickness of 40 μm; ultrasonically cleaning the thickness-polarized piezoelectric fiber and removing it after drying; Epoxy resin is spin-coated on the surface of the flexible interdigitated electrode, and piezoelectric fibers are placed in sequence to complete the composite of the piezoelectric fibers and the flexible electrode.

10. The method for preparing a composite magnetic field energy recovery device based on magnetic-mechanical-electrical coupling and current mutual induction according to claim 9, characterized in that: The preparation method of the two-phase composite of piezoelectric material and magnetostrictive material in step (4) is as follows: the piezoelectric fiber of the composite flexible electrode is cured at room temperature for 24 hours using vacuum compression technology and then taken out to form a piezoelectric-piezoelectric macro-fiber composite material; epoxy resin is applied to the surface of the piezoelectric macro-fiber composite material and the magnetostrictive beam (10) to bond the two parts, and the composite material is taken out after curing.

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