Multi-mode coupling resonant energy harvester

Abstract

The invention relates to the technical field of electromagnetic vibration energy, and discloses a multi-mode coupling resonant energy harvester, which comprises a magnet unit, a coil unit, a rigid-flexible hybrid beam and a shell, and is characterized in that the magnet unit comprises two magnet pieces with opposite polarities, and the magnet pieces are respectively arranged on the upper side and the lower side of the rigid-flexible hybrid beam; the coil unit comprises two coil pieces, the coil pieces are arranged on the upper side and the lower side of the rigid-flexible hybrid beam respectively, and the coil unit is located on the outer edge of the rigid-flexible hybrid beam; the shell is arranged on one side of the magnet unit, the transduction mechanism composed of the magnet unit and the coil unit is fixed to the shell, the shell is located between the magnet unit and the coil unit, the rigid-flexible hybrid beam is arranged on one side of the shell and fixedly connected with the shell, and the rigid-flexible hybrid beam comprises a rigid beam and a flexible beam. The rigid beams are arranged on the two sides of the flexible beam respectively, the rigid beams are connected with the flexible beam, the transduction mechanism is driven by the shell to vibrate in a forced mode, and broadband vibration under the condition of small size is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic vibration energy harvesters, and in particular to a multi-mode coupled resonant energy harvester. Background Art

[0002] Electromagnetic vibration energy harvesters, based on the principle of Faraday induction, convert widespread vibrational mechanical energy into electrical energy, which they then use to power nearby sensors or microelectronic devices, enabling long-term online operation of these components. This type of self-harvesting energy harvester can replace or complement traditional chemical batteries. In IoT systems with a large number of distributed sensor nodes, this technology not only meets the requirements for green energy applications but also offers a simple and efficient deployment solution that saves manpower and material costs. This technology holds significant practical value and research significance for building intelligent, intensive, and green IoT systems.

[0003] Currently, traditional vibration energy harvesters are based on single-degree-of-freedom vibration system designs, consisting of only a single spring or cantilever beam. These systems exhibit typical single-resonance peak characteristics, and their eigenfrequency is often required to match the frequency of the ambient vibration source to achieve maximum energy harvesting efficiency. However, the difficulty lies in the variable and random frequencies of ambient vibration sources, making single-resonance devices with narrow frequency bands unsuitable for vibration scenarios with a wide frequency range. Furthermore, high output power often relies on large structures, but the stringent limitations on device size in industrial scenarios require devices to be miniaturized while maintaining high efficiency. Traditional vibration energy harvesters cannot achieve both high output power and a compact design. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-mode coupled resonant energy harvester, which effectively solves the difficulty of traditional vibration energy harvesters in achieving both high output power and miniaturized design.

[0005] In order to achieve the above-mentioned objectives, the present invention provides a multi-modal coupled resonant energy harvester, which includes a magnet unit, a coil unit, a rigid-flexible hybrid beam and a shell; the magnet unit includes two magnet parts with opposite polarities, which are respectively arranged on the upper and lower sides of the rigid-flexible hybrid beam, and the magnet parts are located at the center of the rigid-flexible hybrid beam; the coil unit includes two coil parts, which are respectively arranged on the upper and lower sides of the rigid-flexible hybrid beam, and the coil unit is located at the outer edge of the rigid-flexible hybrid beam; the shell is arranged on one side of the magnet unit, and the transducer mechanism composed of the magnet unit and the coil unit is fixed on the shell, and the shell is located between the magnet unit and the coil unit, the rigid-flexible hybrid beam is arranged on one side of the shell and fixedly connected to the shell, the rigid-flexible hybrid beam includes a rigid beam and a flexible beam, and the number of rigid beams is multiple, the rigid beams are respectively arranged on the upper and lower sides of the flexible beam, and the rigid beam and the flexible beam are connected to each other, the rigid-flexible hybrid beam cooperates with the transducer mechanism based on its own elastic characteristics, and the shell drives the transducer mechanism to vibrate through vibration to achieve wide-band vibration.

[0006] Furthermore, the rigid beam and the flexible beam are connected by gluing.

[0007] In one embodiment, the rigid-flexible hybrid beam includes a butterfly portion, which is disposed at the center of the rigid-flexible hybrid beam and connected to the magnet component. The butterfly portion is used to fix the magnet unit.

[0008] In one embodiment, the rigid-flexible hybrid beam further includes a first fixing portion, which is disposed on the outer periphery of the butterfly portion. The first fixing portion is provided with a plurality of bolt holes. The first fixing portion is connected to the outer shell through the bolt holes, and the rigid-flexible hybrid beam generates forced vibration through the outer shell.

[0009] In one embodiment, the rigid-flexible hybrid beam further includes a second fixing portion, which is disposed on the periphery of the first fixing portion, is connected to the coil component, and is used to fix the coil unit.

[0010] In one embodiment, the first fixing portion and the second fixing portion are both annular structures and are equally divided into four supporting units with the same structure along the circumferential direction.

[0011] In one embodiment, the flexible beam further includes four connecting parts, and the outer periphery of the butterfly-shaped part is evenly radially provided with four connecting parts, each connecting part is provided between two adjacent support units, and the connecting part is used to fix the support units.

[0012] In one embodiment, the rigid beam is made of metal material, and serves as a reinforcing microstructure fixed to the flexible beam, and the flexible beam is made of polyimide.

[0013] Furthermore, the material of the rigid beam is epoxy resin-based glass fiber reinforced composite material, and the material of the flexible beam can be silicone rubber, fluororubber and thermoplastic polyurethane.

[0014] In one embodiment, the magnet unit further includes a rivet, which is vertically arranged in the middle of two adjacent magnet members. The rivet is used to reinforce the magnet members to form an array structure and enhance the local magnetic field strength.

[0015] In one embodiment, the coils are connected in a cascade manner, which is either series or parallel, and the series or parallel mode is selected by a switching circuit, wherein the series mode is used to increase the output voltage and the parallel mode is used to increase the output power.

[0016] In one embodiment, under the excitation of an external vibration source, when the rigid-flexible hybrid beam vibrates with the shell, the coil unit and the magnet unit have relative displacement due to the difference in amplitude and phase. The transducer mechanism composed of the coil unit and the magnet unit has multiple resonance peaks, so that the coil unit in the energy harvester generates voltage within a wider frequency band and outputs electrical energy.

[0017] Compared with the prior art, the multi-modal coupled resonant energy harvester of the embodiment of the present invention has the following beneficial effects: the transducer mechanism composed of the magnet unit and the coil unit converts mechanical vibration energy into electrical energy by using the principle of electromagnetic induction, the two magnet parts with opposite polarities are respectively arranged at the centers of the upper and lower sides of the rigid-flexible hybrid beam, and the two coil parts are respectively arranged at the outer edges of the upper and lower sides of the rigid-flexible hybrid beam. When the rigid-flexible hybrid beam vibrates under the drive of the outer shell, relative movement occurs between the magnet part and the coil part, cutting the magnetic flux lines to generate induced electromotive force, thereby realizing efficient energy conversion. This seesaw design enables the energy harvester to generate a larger induced current at a smaller vibration amplitude, thereby improving the efficiency of energy collection; the rigid-flexible hybrid beam is composed of a rigid beam and a flexible beam, and this special The structure gives it multiple vibration modes, and different modes correspond to different natural frequencies. When the external vibration frequency changes, the harvester can generate resonant responses near multiple frequency points, which enables the energy harvester to effectively collect energy within a wider frequency range, overcoming the limitation of traditional single-mode energy harvesters that can only work efficiently near a single frequency; the rigid-flexible hybrid beam cooperates with the transducer mechanism based on its own elastic characteristics. The vibration characteristics of the rigid-flexible hybrid beam can optimize the relative movement between the magnet and the coil, making the relative movement more regular and efficient, further enhancing the energy conversion effect. Through the physical coupling optimization of the magnet, coil and rigid-flexible hybrid beam, the pain points of traditional vibration energy harvesters such as narrow frequency band, low efficiency and large size are solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of a multi-mode coupled resonant energy harvester according to an embodiment of the present invention.

[0019] Figure 2 It is a cross-sectional view of a multi-mode coupled resonant energy harvester according to an embodiment of the present invention.

[0020] Figure 3 1 is an exploded view of a multi-mode coupled resonant energy harvester according to an embodiment of the present invention.

[0021] Figure 4 It is a structural schematic diagram of a rigid-flexible hybrid beam in a multi-modal coupled resonant energy harvester according to an embodiment of the present invention.

[0022] Figure 5 It is an exploded diagram of the rigid-flexible hybrid beam in the multi-modal coupled resonant energy harvester according to an embodiment of the present invention.

[0023] Figure 6 It is a front view of a rigid-flexible hybrid beam in a multi-mode coupled resonant energy harvester according to an embodiment of the present invention.

[0024] Figure 7 It is a vibration mode simulation diagram of the multi-mode coupled resonant energy harvester according to an embodiment of the present invention.

[0025] Figure 8 This is a graph of the amplitude-frequency characteristics of the experimental test of the multi-mode coupled resonant energy harvester according to an embodiment of the present invention.

[0026] In the figure, 10, magnet unit; 11, magnet member;

[0027] 20. Coil unit; 21. Coil component;

[0028] 30. Rigid-flexible hybrid beam; 31. Rigid beam; 311. Butterfly-shaped portion; 312. First fixing portion; 3121. Bolt hole; 313. Second fixing portion; 32. Flexible beam; 321. Connecting portion;

[0029] 40. Shell. DETAILED DESCRIPTION

[0030] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0031] In the description of the present invention, it should be understood that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element. The terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, it may be internal communication between two elements or an interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the description of the present invention, it should be understood that the terms "height", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used in the present invention to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] In describing the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being described. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features.

[0034] like Figures 1 to 6As shown, an embodiment of the present invention preferably provides a multi-mode coupled resonant energy harvester, which includes a magnet unit 10, a coil unit 20, a rigid-flexible hybrid beam 30 and a housing 40; the magnet unit 10 includes two magnets 11 with opposite polarities, the magnets 11 are respectively arranged on the upper and lower sides of the rigid-flexible hybrid beam 30, and the magnets 11 are located at the center of the rigid-flexible hybrid beam 30; the coil unit 20 includes two coils 21, the coils 21 are respectively arranged on the upper and lower sides of the rigid-flexible hybrid beam 30, and the coil unit 20 is located at the outer edge of the rigid-flexible hybrid beam 30; the housing 40 is arranged on one side of the magnet unit 10, and the magnets 1 ... magnets 11 are located at the center of the rigid-flexible hybrid beam 30; the coil unit 20 includes two coils 21, the coils 21 are respectively arranged on the upper and lower sides of the rigid-flexible hybrid beam 30, and the coil unit 20 is located at the outer edge of the rigid-flexible hybrid beam 30. The transducer mechanism composed of the iron unit 10 and the coil unit 20 is fixed on the shell 40, and the shell 40 is located between the magnet unit 10 and the coil unit 20. The rigid-flexible hybrid beam 30 is arranged on one side of the shell 40 and is fixedly connected to the shell 40. The rigid-flexible hybrid beam 30 includes a rigid beam 31 and a flexible beam 32. There are two rigid beams 31, and the rigid beams 31 are respectively arranged on the upper and lower sides of the flexible beam 32, and the rigid beam 31 and the flexible beam 32 are connected to each other. The rigid-flexible hybrid beam 30 cooperates with the transducer mechanism based on its own elastic characteristics. The shell 40 drives the transducer mechanism to vibrate through vibration to achieve wide-band vibration.

[0035] Based on the above technical features, the embodiment of the present invention uses a transducer mechanism composed of a magnet unit 10 and a coil unit 20, and utilizes the principle of electromagnetic induction to convert mechanical vibration energy into electrical energy. Two magnet parts 11 with opposite polarities are respectively arranged at the upper and lower centers of the rigid-flexible hybrid beam 30, and two coil parts 21 are respectively arranged at the upper and lower outer edges of the rigid-flexible hybrid beam 30. When the rigid-flexible hybrid beam 30 vibrates driven by the shell 40, relative movement occurs between the magnet part 11 and the coil part 21, cutting the magnetic lines of force to generate induced electromotive force, thereby realizing efficient energy conversion. This seesaw design enables the energy harvester to generate a larger induced current at a smaller vibration amplitude, thereby improving the efficiency of energy harvesting. The rigid-flexible hybrid beam 30 is composed of a rigid beam 31 and a flexible beam 32. This special structure makes It has multiple vibration modes, and different modes correspond to different natural frequencies. When the external vibration frequency changes, the harvester can generate resonant responses near multiple frequency points, which enables the energy harvester to effectively collect energy within a wider frequency range, overcoming the limitation that traditional single-mode energy harvesters can only work efficiently near a single frequency; the rigid-flexible hybrid beam 30 cooperates with the transducer mechanism based on its own elastic characteristics. The vibration characteristics of the rigid-flexible hybrid beam 30 can optimize the relative movement between the magnet part 11 and the coil part 21, making the relative movement more regular and efficient, further enhancing the energy conversion effect. Through the physical coupling optimization of the magnet part 11, the coil part 21 and the rigid-flexible hybrid beam 30, the pain points of the traditional vibration energy harvester such as narrow frequency band, low efficiency and large size are solved.

[0036] Furthermore, the rigid beam 31 and the flexible beam 32 are connected by gluing. This is a surface-contact connection method that, compared to point or line contact, allows for more uniform stress distribution between the rigid beam 31 and the flexible beam 32. During vibration, stress is not concentrated at a few points, but is instead distributed across the entire gluing surface.

[0037] As some embodiments of the present invention, Figures 4 to 6 As shown, the rigid-flexible hybrid beam 30 includes a butterfly portion 311, which is located at the center of the rigid-flexible hybrid beam 30. The butterfly portion 311 is connected to the magnet part 11, and the butterfly portion 311 is used to fix the magnet unit 10. The special shape design of the butterfly portion 311 can effectively disperse stress. During the operation of the energy harvester, the rigid-flexible hybrid beam 30 will be subjected to various forces caused by vibration. The butterfly portion 311, through its unique geometric structure, disperses the concentrated stress to a larger area, avoids excessive local concentration of stress, and thus reduces the risk of fatigue damage to the structure. The butterfly portion 311 is connected to the magnet part 11, providing a stable fixing method for the magnet unit 10. During the operation of the energy harvester, the magnet part 11 needs to move relative to the coil part 21 to generate an induced electromotive force, which requires that the magnet part 11 must be firmly fixed on the rigid-flexible hybrid beam 30 to avoid loosening or displacement during vibration.

[0038] As some embodiments of the present invention, Figures 4 to 6 As shown, the rigid-flexible hybrid beam 30 also includes a first fixing portion 312, which is disposed on the outer periphery of the butterfly portion 311. The first fixing portion 312 is provided with multiple bolt holes 3121. The first fixing portion 312 is connected to the housing 40 via the bolt holes 3121, allowing the rigid-flexible hybrid beam 30 to generate forced vibrations through the housing 40. The first fixing portion 312 is provided with multiple bolt holes 3121 and is connected to the housing 40 via bolts. This multi-point fixing method greatly enhances the strength and stability of the connection between the rigid-flexible hybrid beam 30 and the housing 40. Compared to single-point connections or simple snap-on connections, bolted connections can withstand greater external forces, ensuring that the rigid-flexible hybrid beam 30 will not loosen or detach from the housing 40 due to vibration during operation of the energy harvester. The first fixing portion 312 is tightly connected to the housing 40 via bolts, allowing vibrations generated by the housing 40 to be efficiently transmitted to the rigid-flexible hybrid beam 30. The bolt connection has good rigidity, which can reduce the loss of vibration energy during the transmission process, ensuring that the rigid-flexible hybrid beam 30 can fully respond to the vibration of the shell 40 and produce corresponding deformation and movement.

[0039] As some embodiments of the present invention, Figures 4 to 6As shown, the rigid-flexible hybrid beam 30 also includes a second fixing portion 313, which is disposed on the periphery of the first fixing portion 312 and connected to the coil component 21. The second fixing portion 313 is used to fix the coil unit 20. The second fixing portion 313 is specifically used to fix the coil unit 20. Its structural design can provide stable support for the coil component 21. During operation of the energy harvester, the rigid-flexible hybrid beam 30 will move with the vibration of the housing 40, thereby driving the magnet unit 10 and the coil unit 20 to produce relative movement. The second fixing portion 313 ensures that the coil component 21 will not loosen, shift, or fall off during vibration, thereby ensuring the stability of the coil unit 20. The second fixing portion 313 is reasonably arranged on the periphery of the first fixing portion 312. This layout helps to disperse the force exerted by the coil unit 20 on the rigid-flexible hybrid beam 30 and reduce stress concentration. If the coil unit 20 is improperly fixed, it may cause the rigid-flexible hybrid beam 30 to be subjected to excessive local force, thereby causing fatigue damage or structural deformation. The existence of the second fixing portion 313 makes the force distribution more uniform, thereby extending the service life of the rigid-flexible hybrid beam 30.

[0040] As some embodiments of the present invention, Figures 4 to 6 As shown, the first fixing portion 312 and the second fixing portion 313 are both annular structures, equally divided circumferentially into four identical support units. The annular structure itself possesses good symmetry, and dividing the first fixing portion 312 and the second fixing portion 313 into four identical support units further enhances this symmetry. During operation of the energy harvester, the rigid-flexible hybrid beam 30 is subjected to forces and vibrations from different directions. This symmetrical structure ensures that stress is evenly distributed across each support unit.

[0041] As some embodiments of the present invention, Figures 4 to 6 As shown, the flexible beam 32 also includes a connecting portion 321, and the number of the connecting portions 321 is four. Four connecting portions 321 are evenly arranged along the radial direction of the outer periphery of the butterfly portion 311. Each connecting portion 321 is arranged between two adjacent support units, and the connecting portion 321 is used to fix the support unit. The four connecting portions 321 are evenly distributed on the outer periphery of the butterfly portion 311, connecting and fixing the adjacent support units to form a tighter and more stable overall structure. In the flexible beam 32, the connecting portion 321 enhances the connection between the various parts of the rigid-flexible hybrid beam 30, making the entire structure less prone to deformation or damage during vibration, thereby improving the reliability and service life of the energy harvester. When the flexible beam 32 is subjected to vibration or external force, stress will be distributed in the structure. The provision of the four connecting portions 321 enables the stress to be more evenly distributed to each support unit and the connecting portion 321, avoiding excessive concentration of stress in a local area.

[0042] As some embodiments of the present invention, Figures 1 to 6As shown, the rigid beam 31 is made of metal and serves as a reinforcing microstructure fixed to the flexible beam 32. The flexible beam 32 is made of polyimide. Metal materials generally have high strength, rigidity, and hardness, and can withstand large external forces and vibrations without significant deformation or damage. In energy harvesters, the rigid beam 31, as a key component for supporting and transmitting vibration energy, requires sufficient strength to ensure structural stability. The reinforcing microstructures can further enhance the strength and rigidity of the rigid beam 31. These microstructures can improve the fatigue resistance and load-bearing capacity of the rigid beam 31 by changing the stress distribution within the metal and reducing stress concentration. Polyimide is a high-performance polymer material with excellent flexibility, heat resistance, and chemical resistance. In the energy harvester, the flexible beam 32 needs to bend and deform with the vibration of the housing 40 to achieve relative movement between the magnet unit 10 and the coil unit 20. The flexibility of polyimide makes it well suited to such deformation requirements. At the same time, its heat resistance and chemical resistance also ensure the stability and reliability of the flexible beam 32 in harsh environments.

[0043] Furthermore, the material of the rigid beam 31 is an epoxy resin-based glass fiber reinforced composite material, and the material of the flexible beam 32 can be silicone rubber, fluororubber and thermoplastic polyurethane. In the epoxy resin-based glass fiber reinforced composite material, the glass fiber serves as a reinforcing phase and has very high tensile strength and elastic modulus, while the epoxy resin serves as a matrix and can bond the glass fibers together to form an integral structure. This composite material combines the high strength of the glass fiber and the good formability of the epoxy resin, so that the rigid beam 31 has high strength and stiffness; silicone rubber, fluororubber and thermoplastic polyurethane all have high elastic deformation capacity, and can undergo large deformation when subjected to external force, and quickly return to their original shape after the external force is removed. This high elastic deformation capacity enables the flexible beam 32 to better adapt to the excitation of external vibration sources and effectively convert vibration energy into electrical energy.

[0044] As some embodiments of the present invention, Figures 1 to 6 As shown, the magnet unit 10 also includes a rivet, which is arranged in the middle of two adjacent magnet parts 11 in the vertical direction. The rivet is used to reinforce the magnet parts 11 to form an array structure and enhance the local magnetic field strength. During the operation of the energy harvester, the magnet unit 10 will move with the vibration of the flexible beam 32. The magnet parts 11 may be relatively displaced due to the inertial force generated by the vibration. The setting of the rivet firmly connects the two adjacent magnet parts 11 together to form a stable array structure. When the magnet parts 11 are closely arranged to form an array structure through rivets, the magnetic fields of adjacent magnet parts 11 will be superimposed and coupled with each other. This superposition effect enhances the magnetic field strength in the local area, thereby improving the electromagnetic induction effect between the magnet unit 10 and the coil unit 20 and increasing the efficiency of energy harvesting.

[0045] As some embodiments of the present invention, Figures 1 to 6 As shown, the coil parts 21 are connected in a cascade manner, which is a series or parallel connection, and the series or parallel mode is selected by switching the circuit, wherein the series mode is used to increase the output voltage, and the parallel mode is used to increase the output power. Under different vibration conditions, the induced electromotive force and current generated by the coil part 21 may be different. By switching the series or parallel mode, the output performance of the energy harvesting system can be optimized. For example, when the vibration is weak, the induced electromotive force generated by a single coil part 21 is small. At this time, the series mode can be used to increase the output voltage so that the system can still work normally; when the vibration is strong, the current generated by a single coil part 21 is large. The parallel mode can be used to increase the output power and make full use of the vibration energy.

[0046] As some embodiments of the present invention, Figures 1 to 6 As shown, under the excitation of an external vibration source, when the rigid-flexible hybrid beam 30 vibrates with the housing 40, the coil unit 20 and the magnet unit 10 experience relative displacement due to differences in amplitude and phase. The transducer mechanism formed by the coil unit 20 and the magnet unit 10 exhibits multiple resonant peaks, enabling the coil unit 20 in the energy harvester to generate voltage and output electrical energy over a wide frequency band. The frequency of an external vibration source is often complex and variable, not a single fixed value. Traditional energy harvesters typically only achieve good energy harvesting efficiency near a specific frequency; once the vibration frequency deviates from this specific value, the energy harvesting efficiency drops significantly. However, a transducer mechanism with multiple resonant peaks can achieve high energy harvesting efficiency at multiple different frequencies, thereby broadening the frequency band for energy harvesting. This wideband energy harvesting capability means that the energy harvester can capture vibration energy across a wider frequency range, converting energy that would otherwise be wasted due to frequency mismatch into electrical energy. This enables the energy harvester to output more electrical energy under the same vibration conditions, converting mechanical energy into electrical energy under a wider range of vibration conditions, and improving overall energy harvesting efficiency.

[0047] Further, if Figure 7As shown, the four typical resonant modes of the multimodal coupled resonant energy harvester of the present invention are as follows: Mode a exhibits out-of-plane piston motion dominated by the magnet, where the magnet's vibration amplitude is significantly higher than that of the coil. This axial motion mode efficiently cuts magnetic flux lines, generating a large induced electromotive force. Mode b exhibits torsional vibration characteristics of the magnet. Its rotational motion reduces the rate of change of magnetic flux, resulting in lower energy conversion efficiency compared to the piston mode, but this mode plays an important role in widening the bandwidth. Mode c transitions to torsional vibration dominated by the coil, where the magnet's amplitude approaches zero. The output voltage of this coupled state is lower than that of the piston mode, but it can form a secondary resonant peak. Mode d returns to the coil's piston motion, with a new resonant peak appearing. In this mode, the coil's vibration frequency is high, the coil's magnetic flux cutting efficiency is highest, and thus the output voltage is the highest. Experiments have shown that although the torsional mode reduces instantaneous energy harvesting efficiency, this multimodal coupling can effectively broaden the operating bandwidth by properly designing the resonant frequency.

[0048] Further, if Figure 8 The amplitude-frequency characteristic curve of the energy harvester used in this invention in a laboratory environment shows that the device has multiple resonant peaks during vibration. Calculated based on an output voltage greater than 800mV, it meets the requirements for power conversion. Under 0.1g acceleration, its frequency band covers 37-72Hz, demonstrating the device's broadband operating characteristics. Next, through precise parameter design, more resonant peaks can be coupled. Combined with the nonlinear characteristics of the rigid-flexible hybrid beam 30, the device's operating frequency band can be further expanded.

[0049] In summary, the embodiment of the present invention provides a multi-modal coupled resonant energy harvester, which has the following beneficial effects compared with the prior art: the transducer mechanism composed of the magnet unit 10 and the coil unit 20 converts mechanical vibration energy into electrical energy by using the principle of electromagnetic induction, and the two magnet parts 11 with opposite polarities are respectively arranged at the upper and lower centers of the rigid-flexible hybrid beam 30, and the two coil parts 21 are respectively arranged at the upper and lower outer edges of the rigid-flexible hybrid beam 30. When the rigid-flexible hybrid beam 30 vibrates under the drive of the outer shell 40, relative movement occurs between the magnet part 11 and the coil part 21, cutting the magnetic flux lines to generate induced electromotive force, thereby realizing efficient energy conversion. The design of this seesaw structure enables the energy harvester to generate a larger induced current at a smaller vibration amplitude, thereby improving the efficiency of energy harvesting; the rigid-flexible hybrid beam 30 consists of a rigid beam 31 and a flexible beam. The rigid-flexible hybrid beam 30 is composed of a plurality of vibration modes, and different modes correspond to different natural frequencies. When the external vibration frequency changes, the harvester can generate a resonant response near multiple frequency points, which enables the energy harvester to effectively collect energy within a wider frequency range, overcoming the limitation that the traditional single-mode energy harvester can only work efficiently near a single frequency; the rigid-flexible hybrid beam 30 cooperates with the transducer mechanism according to its own elastic characteristics. The vibration characteristics of the rigid-flexible hybrid beam 30 can optimize the relative motion between the magnet part 11 and the coil part 21, making the relative motion more regular and efficient, further enhancing the effect of energy conversion, and through the physical coupling optimization of the magnet part 11, the coil part 21 and the rigid-flexible hybrid beam 30, the pain points of the traditional vibration energy harvester such as narrow frequency band, low efficiency and large size are solved.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-mode coupled resonant energy harvester, characterized in that: include: Magnet unit, coil unit, rigid-flexible hybrid beam and housing; The magnet unit includes two magnets with opposite polarities, the magnets being respectively arranged on the upper and lower sides of the rigid-flexible hybrid beam, and the magnets being located at the center of the rigid-flexible hybrid beam; The coil unit includes two coil parts, which are respectively arranged on the upper and lower sides of the rigid-flexible hybrid beam, and the coil unit is located at the outer edge of the rigid-flexible hybrid beam; The housing is provided on one surface of the magnet unit, and the transducer mechanism composed of the magnet unit and the coil unit is fixed on the housing, and the housing is located between the magnet unit and the coil unit; The rigid-flexible hybrid beam is arranged on one side of the shell and is fixedly connected to the shell. The rigid-flexible hybrid beam includes a rigid beam and a flexible beam. There are multiple rigid beams, and the rigid beams are respectively arranged on the upper and lower sides of the flexible beam, and the rigid beam and the flexible beam are connected to each other. The rigid-flexible hybrid beam cooperates with the transducer mechanism based on its own elastic characteristics. The shell drives the transducer mechanism to vibrate through vibration to achieve wide-band vibration.

2. The multi-mode coupled resonant energy harvester according to claim 1, characterized in that: The rigid-flexible hybrid beam includes a butterfly-shaped portion, the butterfly-shaped portion is located at the center of the rigid-flexible hybrid beam, the butterfly-shaped portion is connected to the magnet component, and the butterfly-shaped portion is used to fix the magnet unit.

3. The multi-mode coupled resonant energy harvester according to claim 2, characterized in that: The rigid-flexible hybrid beam also includes a first fixing portion, which is arranged on the outer periphery of the butterfly portion. The first fixing portion is provided with a plurality of bolt holes. The first fixing portion is connected to the outer shell through the bolt holes. The rigid-flexible hybrid beam generates forced vibration through the outer shell.

4. The multi-mode coupled resonant energy harvester according to claim 3, characterized in that: The rigid-flexible hybrid beam further includes a second fixing portion, which is disposed on the outer periphery of the first fixing portion and is connected to the coil component, and is used to fix the coil unit.

5. The multi-mode coupled resonant energy harvester according to claim 4, characterized in that: The first fixing portion and the second fixing portion are both annular structures and are equally divided into four supporting units with the same structure along the circumferential direction.

6. The multi-mode coupled resonant energy harvester according to claim 5, characterized in that: The flexible beam further includes four connecting parts, and the four connecting parts are evenly arranged radially on the outer periphery of the butterfly-shaped part. Each connecting part is arranged between two adjacent support units, and the connecting part is used to fix the support unit.

7. The multi-mode coupled resonant energy harvester according to claim 1, characterized in that: The rigid beam is made of metal material. The rigid beam is fixed to the flexible beam as a reinforcing microstructure. The flexible beam is made of polyimide.

8. The multi-mode coupled resonant energy harvester according to claim 1, characterized in that: The magnet unit further includes a rivet, which is vertically arranged in the middle of two adjacent magnet members. The rivet is used to reinforce the magnet members to form an array structure and enhance the local magnetic field strength.

9. The multi-mode coupled resonant energy harvester according to claim 1, characterized in that: The coil components are connected in a cascade manner, which is a series connection or a parallel connection, and the series or parallel connection mode is selected by a switching circuit, wherein the series connection mode is used to increase the output voltage, and the parallel connection mode is used to increase the output power.

10. The multi-mode coupled resonant energy harvester according to claim 1, characterized in that: Under the excitation of an external vibration source, when the rigid-flexible hybrid beam vibrates along with the shell, the coil unit and the magnet unit have relative displacement due to the difference in amplitude and phase. The transducer mechanism composed of the coil unit and the magnet unit has multiple resonance peaks, so that the coil unit in the energy harvester generates voltage within a wider frequency band and outputs electrical energy.

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