Energy harvesting system based on hyperbolic scatterers in zero-index metasurfaces and applications thereof

Abstract

The application relates to an energy collection system based on hyperbolic scatterers in zero refractive index superstructures, comprising: a circuit board; a plurality of transverse conductive lines and a plurality of longitudinal conductive lines arranged on the circuit board, which are staggered and separated to form a plurality of longitudinal line segments and a plurality of transverse line segments; an HMM region formed on the circuit board, wherein each transverse line segment in the HMM region is connected with a first capacitor; and a ZIM region formed on the circuit board, wherein the ZIM region is located outside the HMM region, and each transverse line segment and each longitudinal line segment in the ZIM region is connected with a second capacitor. The energy collection system introduces a hyperbolic cavity (HMM) in the ZIM, uses the hyperbolic cavity as a subwavelength scatterer for photon doping, and can be realized by arranging planar conductive lines on the circuit board, thereby effectively solving the problem that high-efficiency energy collection is difficult to realize in a subwavelength scale in the prior art.

Description

Technical Field

[0001] This invention relates to the field of foundation pit construction engineering, and specifically to an energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface and its application. Background Technology

[0002] The interaction between light and matter depends on the material's electromagnetic response parameters (i.e., dielectric constant). and permeability Metamaterials, achieved through artificial microstructures, allow for flexible manipulation of the system's equivalent electromagnetic parameters, providing a powerful research platform for efficient optical manipulation in material systems beyond natural materials. Among these, ultrathin zero-refractive-index metamaterials, also known as zero-refractive-index metasurfaces (ZIMs), are a class of materials with a refractive index close to zero. Metamaterials, particularly ZIMs, have become a research hotspot due to their unique ability to manipulate electromagnetic waves. When the relative permittivity and / or permeability of ZIMs approach zero, they correspond to zero electric permeability (…). -near-zero (ENZ) and magnetic zero ( -Near-zero (MNZ) materials have electromagnetic waves with wavelengths approaching infinity and propagation phases almost zero. These properties give ZIMs broad application prospects, such as optical compression, directional radiation, nonlinearity, and magneto-optical effect enhancement.

[0003] In recent years, with the continuous improvement of micro-nano fabrication technology, various tiny scatterers have been introduced into metamaterials to study new electromagnetic scattering phenomena. Especially in Zig-Metal Injections (ZIMs), even a small amount of doping can significantly affect the overall macroscopic electromagnetic response. Researchers have achieved novel superreflection and optical "stealth" phenomena by introducing perfectly electrically and magnetically conductive materials of arbitrary shapes into impedance-matched ZIMs. In particular, inspired by semiconductor doping, researchers have found that doped ZIMs can be equivalent to homogeneous media, and the corresponding equivalent electromagnetic parameters strongly depend on the properties of the dopant impurities, thus proposing the new concept of "optical doping." One important application of optical doping in ZIMs is energy harvesting and wireless power transfer. Generally, optical resonators can effectively confine electromagnetic fields, thus acting as receivers for energy harvesting. However, the efficient energy harvesting capability of resonators usually depends on a large receiver size, and achieving efficient energy harvesting at the subwavelength scale remains a challenge. Researchers have theoretically revealed that the optical cross-section of a single local resonator in ZIMs can be significantly enhanced. Similar to optical "black holes," tiny scatterers in ZIMs can achieve efficient collection of electromagnetic waves. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface and its application, solving the problem that the existing energy harvesting capability is strongly dependent on the size of the receiver and that it is difficult to achieve efficient energy harvesting at the subwavelength scale.

[0005] The technical solution to achieve the above objectives is:

[0006] This invention provides an energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface, comprising:

[0007] Circuit board;

[0008] Several transverse conductive lines are arranged on the circuit board;

[0009] Several longitudinal conductive lines are arranged on the circuit board. The longitudinal conductive lines are perpendicularly connected to the transverse conductive lines. Several longitudinal conductive lines are divided into several longitudinal line segments by several transverse conductive lines. Several transverse conductive lines are divided into several transverse line segments by several longitudinal conductive lines.

[0010] An HMM region is formed on the circuit board, and a first capacitor is connected to each transverse line segment within the HMM region;

[0011] A ZIM region is formed on the circuit board, the ZIM region is located outside the HMM region, and a second capacitor is connected to each transverse line segment and each longitudinal line segment within the ZIM region.

[0012] The energy harvesting system of the present invention introduces a hyperbolic cavity (HMM) into the ZIM, uses the hyperbolic cavity as a subwavelength scatterer for photon doping, and can be realized by laying planar conductive lines on the circuit board, effectively solving the problem of achieving efficient energy harvesting at the subwavelength scale in the prior art.

[0013] A further improvement of the energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface of the present invention is that it further includes calculating the capacitance value of the second capacitor using the following formula:

[0014] Formula 1,

[0015] In formula 1, The equivalent dielectric constant of the metasurface formed by the HMM and ZIM regions is given. Let be the equivalent permeability of the metasurface formed in the HMM region along the x-direction of the structure. Capacitance per unit length Inductance per unit length The dielectric constant of vacuum is . The permeability of vacuum. The equivalent permeability of the metasurface formed in the ZIM region. g is the system's structural factor. ,in and These are the intrinsic impedance and effective wave impedance of the structure, respectively. Angular frequency, , Let be the frequency of the HMM and ZIM regions, and d be the side length of several squares formed by the transverse and longitudinal lines. Given the capacitance value of the first capacitor, we can obtain... The value of , C is the second capacitor.

[0016] A further improvement of the energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface is that it also includes resistors on the outermost transverse and longitudinal circuit segments.

[0017] A further improvement of the energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface is that it further includes at least one excitation source located in the ZIM region.

[0018] A further improvement of the energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface is that the HMM region is located in the middle of the circuit board.

[0019] A further improvement of the energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface is that the HMM region is located on either side of the circuit board.

[0020] A further improvement of the energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface is that the transverse conductive lines and the longitudinal conductive lines are arranged at equal intervals.

[0021] The present invention provides an energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface, which can be further used in wireless power transmission systems. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface of the present invention, which is equipped with a point source excitation.

[0023] Figure 2 This is an equivalent circuit diagram of the energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface according to the present invention.

[0024] Figure 3This refers to the equivalent electromagnetic parameters of the circuit-based metamaterial in the energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface, as described in this invention.

[0025] Figure 4 This is the dispersion relation diagram at a reference frequency of 1.06 GHz in the medium hyperbolic scatterer energy harvesting system based on a zero-refractive-index metasurface of the present invention.

[0026] Figure 5 This is a schematic diagram of the structure of the energy harvesting system for a hyperbolic scatterer based on a zero-refractive-index metasurface of the present invention, which is equipped with multiple point source excitations.

[0027] Figure 6 To establish an electric field distribution excited by a point source on the energy harvesting system of a hyperbolic scatterer in a zero-refractive-index metasurface, this invention is proposed.

[0028] Figure 7 This invention relates to the electric field distribution of multiple point source excitations on an energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface.

[0029] Figure 8 This is a local Poynting vector distribution diagram of the system under point source excitation in the full-field simulation of the energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface according to the present invention.

[0030] Figure 9 This is a local Poynting vector distribution diagram of the system under multiple point source excitations in the energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface, as simulated in the full-field simulation of the present invention.

[0031] Figure 10 This is the electric field distribution experimentally measured in the energy harvesting system of a hyperbolic scatterer in a zero-refractive-index metasurface, as per the present invention.

[0032] Figure 11 This is the distribution of the local Poynting vector experimentally measured in the energy harvesting system of the hyperbolic scatterer in the zero-refractive-index metasurface of this invention.

[0033] Figure 12 for Figure 11 A magnified view of region A in the diagram.

[0034] Figure 13 for Figure 11 A magnified view of region B in the diagram. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0036] See Figure 1This invention provides an energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface. A hyperbolic cavity (HMM) is introduced into the ZIM as a subwavelength scatterer for "optical doping," and the optical "black hole" effect under different excitation sources (point sources and plane waves (composed of multiple point sources)) is experimentally observed using precise near-field detection techniques. The energy harvesting system of this invention directly measures the energy flux distribution experimentally and can be applied to wireless power transfer technology. This energy harvesting system opens a new path for realizing miniaturized on-chip integrated energy devices and has wider applicability, extending to other classical wave systems such as sound waves, elastic waves, and water waves. The energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface of this invention will be described below with reference to the accompanying drawings.

[0037] See Figure 1 This invention presents a schematic diagram of a point source excitation structure on an energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface. The following is a related diagram. Figure 1 The present invention describes an energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface.

[0038] like Figure 1 As shown, the energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface of the present invention includes a circuit board 20, lateral conductive lines 21, longitudinal conductive lines 22, an HMM region 23, a first capacitor 24, a ZIM region, and a second capacitor 25. Several lateral conductive lines 21 are arranged on the circuit board 20. Several longitudinal conductive lines 22 are also arranged on the circuit board 20. The longitudinal conductive lines 22 are perpendicularly connected to the lateral conductive lines 21. Several longitudinal line segments 221 are formed on the longitudinal conductive lines 22 by the lateral conductive lines 21, and several lateral line segments 211 are formed on the lateral conductive lines 21 by the longitudinal conductive lines 22. The HMM region 23 is formed on the circuit board 20, and the first capacitor 24 is connected to each lateral line segment 211 within the HMM region 23. The ZIM region is formed on the circuit board, located outside the HMM region, and the second capacitor 25 is connected to each lateral line segment 211 and each longitudinal line segment 221 within the ZIM region.

[0039] The circuit board 20 of the present invention and the transverse conductive lines 21 and longitudinal conductive lines 22 arranged on it constitute a planar transmission line (TL) platform. Figure 1This is a schematic diagram of the energy harvesting system of the present invention, wherein the line widths of the transverse conductive line 21 and the longitudinal conductive line 22 can be designed according to actual needs, and the dimensions of the first capacitor 24 and the second capacitor 25 connected on the transverse conductive line 21 and the longitudinal conductive line 22 are smaller than the line widths of the corresponding conductive lines.

[0040] In one specific embodiment of the present invention, the energy harvesting system of the present invention further includes calculating the capacitance value of the second capacitor using the following formula: Formula 1,

[0041] In formula 1, The equivalent dielectric constant of the metasurface formed by the HMM and ZIM regions is given. Let be the equivalent permeability of the metasurface formed in the HMM region along the x-direction of the structure. Capacitance per unit length Inductance per unit length The dielectric constant of vacuum is . The permeability of vacuum. The equivalent permeability of the metasurface formed in the ZIM region. g is the system's structural factor. ,in and These are the intrinsic impedance and effective wave impedance of the structure, respectively. Angular frequency, , Let be the frequency of the HMM and ZIM regions, and d be the side length of several squares formed by the transverse and longitudinal lines. Given the capacitance value of the first capacitor, we can obtain... The value of , C is the second capacitor.

[0042] Specifically, a hyperbolic metamaterial (HMM) was formed in the HMM region 23 by loading a first capacitor 24 in the x-direction, and an MNZ (magnetic null) was formed in the ZIM region by loading second capacitors in the x and y directions. -near-zero) metasurfaces. For example... Figure 2 As shown, the corresponding equivalent unit circuit models of HMM and MZN are displayed.

[0043] First, calculate using the following formula. and :

[0044] Formula 2,

[0045] Formula 3,

[0046] Formula 4,

[0047] Formula 5,

[0048] In Formulas 2 to 5, w represents the linewidth of the horizontal conductive line 21 and the vertical conductive line 22, and h represents the thickness of the circuit board 20. The dielectric constant of circuit board 20 , The dielectric constant of vacuum is . Let be the permeability of vacuum, where , .

[0049] The calculated and Substituting into Formula 1, we get and .

[0050] Given the capacitance value of the first capacitor C1, for example, C1 = 3pF, the frequency f = 1.06GHz of the hyperbolic cavity mode is obtained through the simulation software CST. Due to the ZIM background... Then, the value of C can be derived from Formula 1, and recorded as the value of the second capacitor C2 set in the ZIM region.

[0051] In one specific embodiment of the present invention, the energy harvesting system further includes resistors 26 disposed on the outermost transverse line segment 211 and longitudinal line segment 221. The resistance value of the resistors can be determined according to the setting parameters of the circuit board 20, the transverse conductive line 21, and the longitudinal conductive line 22, and the perfectly matched absorption boundary conditions can be achieved by setting the resistors.

[0052] In one specific embodiment of the present invention, the energy harvesting system of the present invention further includes at least one excitation source 30 located in the ZIM region.

[0053] Figure 1 The structure shown is configured with an excitation source 30, which can be called a point source excitation structure; Figure 5 The structure shown has seven excitation sources 30, which cover the width of the circuit board 20, and can be described as a plane wave excited structure. Because a hyperbolic cavity (HMM) is embedded in the ZIM, this arrangement of the excitation sources 30 achieves a concentration effect of electromagnetic waves at the hyperbolic cavity. (See reference...) Figure 6 and Figure 7 The effect shown.

[0054] In one specific embodiment of the present invention, the HMM region 23 is located in the middle of the circuit board 20. Alternatively, the HMM region 23 is located on any side of the circuit board 20.

[0055] In one specific embodiment of the present invention, the transverse conductive lines 21 and the longitudinal conductive lines 20 are arranged at equal intervals.

[0056] The present invention provides an energy harvesting system based on hyperbolic scatterers in a zero-refractive-index metasurface, which can be further used in wireless power transmission systems.

[0057] The performance of the energy harvesting system of the present invention will be described below with an example.

[0058] like Figure 1 As shown, 13 horizontal conductive lines and 19 vertical conductive lines are arranged on the circuit board, with the horizontal and vertical conductive lines interleaved to form several grid cells. The line width of the horizontal and vertical lines is 2.8 mm. The dimensions of the hyperbolic cavity (HMM) and ZIM background are 6*5 grid cells and 18*12 grid cells, respectively. The resistors set on the outermost horizontal and vertical line segments have a resistance of 71.4 Ω.

[0059] Given that the capacitance of the first capacitor is 3.0pF, the capacitance of the second capacitor is calculated to be 5.9pF according to Formula 1 above. This completes the construction of the HMM and MNZ on the circuit board. Figure 3 The long dashed lines and short dashed lines (solid lines) in the diagram represent the effective electromagnetic parameters of a circuit-based HMM (MNZ dielectric) with series capacitance. At the reference frequency f = 1.06 GHz shown by the pentagram, the MNZ dielectric ( ) and HMM ( The dispersion relation in a circuit-based metasurface can be described as follows:

[0060] Formula 6,

[0061] In formula 6, and These are the components of the wave vector within the medium in the x and y directions, respectively. It is the wave vector in vacuum. According to Equation 6, the dispersion relation of HMM and MNZ media based on the circuit is as follows: Figure 4 As shown, from Figure 4 As can be clearly seen, at the reference frequency f=1.06GHz, the iso-frequency contours (IFC) of the MNZ medium (small black circle in the center) are isotropic closed circles, while the IFC of the HMM (solid gray line) is an anisotropic open hyperbola. The large dashed circle represents the IFC of double positive materials (DPS).

[0062] Theoretical analysis reveals that the ZIM background, due to its small supported wave vector, has a very limited number of internal transmission channels. When a high-refractive-index dielectric scatterer is placed within a ZIM, its internal support for a large number of scattering channels can be utilized to achieve effective energy harvesting. Hyperbolic scatterers (HMMs), with their open intermolecular current distribution (IFC), can, under ideal conditions, support an infinite number of scattering channels with varying wave vectors. When HMMs are used as subwavelength scatterers to replace conventional dielectric materials in a ZIM, the hyperbolic scatterer and the ZIM background material support the most and fewest scattering channels, respectively. Therefore, it is expected that the hyperbolic scatterer in the ZIM will achieve ideal energy harvesting performance.

[0063] The performance of the energy harvesting system of the present invention will be explained below through experiments.

[0064] The designed TL structure is based on a 1.6mm thick commercial printed circuit board F4B (… The system was manufactured on the ZIM platform, and then the electromagnetic response of the energy harvesting system based on the hyperbolic cavity in ZIM was specifically studied.

[0065] To conduct numerical studies of the system, a three-dimensional full-wave simulation was performed using the commercial software CST Microwave Studio. Figure 1 This is a schematic diagram of a point source excitation structure. Figure 5 This is a schematic diagram of a plane wave excitation structure. In actual experimental conditions, a 50Ω SMA connector is placed at the center of the sample as the excitation source.

[0066] from Figure 6 and Figure 7 Simulated Distribution and Figure 8 and Figure 9 As can be seen from the corresponding Poynting vector distribution, the designed energy harvesting system based on a hyperbolic cavity in ZIM achieves the electromagnetic wave concentration effect. The energy flux distribution is represented by the local Poynting vector. From... Figure 6 As can be seen, the electric field generated by the point source converges into the superscatterer, where black represents the portion with a larger electric field. Figure 8 Electromagnetic waves propagating in all directions from a point source are collected into a hyperbolic scatterer (marked by the shaded area) as they pass near the hyperbolic cavity. Due to the cancellation mechanism between forward and backward energy collection, the total Poynting vector in front of the hyperbolic cavity is very small. While point sources achieve energy harvesting, similar energy harvesting effects to optical "black holes" can also occur with plane waves. Using seven point sources spaced 2d apart to represent plane waves, such as... Figure 5 As shown. Simulated. and the corresponding energy flow distribution, such as Figure 7 and 9As shown, similar to point sources, the electric field generated by plane waves can also be well collected in hyperbolic cavities, with even better collection results. Therefore, a circuit-based metasurface demonstrates energy harvesting in a hyperbolic cavity against an MNZ background.

[0067] To observe energy harvesting in a hyperbolic cavity within an MNZ medium, a test sample was fabricated and experimentally verified. At a frequency of 1.038 GHz (the error from the simulated frequency arises from the sample fabrication), the measured energy was... and energy flow distribution such as Figure 10 and Figure 11 As shown. Figure 11 Enlarged views of areas A and B enclosed by black and light gray rectangles are shown below. Figure 12 and Figure 13 As shown. It can be seen that, Figure 12 There is competitive cancellation between the forward and backward energy collection in region A (in front of the hyperbolic scatterer). Energy collection can be clearly observed in region B (back of the hyperbolic scatterer) in Figure 13, where the direction of the local Poynting vector is indicated by the arrow. Figure 12 and Figure 13 The measurement results in Figure 8 and Figure 9 The simulation results are consistent with those in the TL platform. Overall, the results not only validate the effectiveness of the circuit-based HMM and MNZ dielectric constructions, but also demonstrate a novel planar subwavelength energy harvesting system built on a circuit-based metasurface. In summary, energy harvesting can be achieved by utilizing the difference in the number of channels supported by hyperbolic cavity scatterers and MNZ background materials. These results provide an ideal research platform for exploring on-chip energy harvesting at the subwavelength scale and can be applied to wireless power transfer technologies.

[0068] The beneficial effects of this invention are as follows:

[0069] 1. A hyperbolic cavity is introduced into the ZIM (Zero Intrusion Motion) as a subwavelength scatterer for photon doping. 2. The energy flux distribution of the harvested energy is directly measured and observed experimentally. 3. The ZIM-based hyperbolic cavity energy harvesting system can be implemented using only a simple planar transmission line platform. 4. The ZIM-based hyperbolic cavity energy harvesting system overcomes the application limitations caused by experimental difficulties. 5. The ZIM-based hyperbolic cavity energy harvesting system opens up a new path for realizing miniaturized on-chip integrated energy harvesting devices. 6. The ZIM-based hyperbolic cavity energy harvesting system has wider applicability than photonic systems and can be extended to other types of waves, such as sound waves and heat waves.

[0070] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. An energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface, characterized in that, include: Circuit board; Several transverse conductive lines are arranged on the circuit board; Several longitudinal conductive lines are arranged on the circuit board. The longitudinal conductive lines are perpendicularly connected to the transverse conductive lines. Several longitudinal conductive lines are divided into several longitudinal line segments by several transverse conductive lines. Several transverse conductive lines are divided into several transverse line segments by several longitudinal conductive lines. An HMM region is formed on the circuit board, and a first capacitor is connected to each transverse line segment within the HMM region; A ZIM region is formed on the circuit board, the ZIM region is located outside the HMM region, and a second capacitor is connected to each transverse line segment and each longitudinal line segment within the ZIM region.

2. The energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface as described in claim 1, characterized in that, It also includes calculating the capacitance value of the second capacitor using the following formula: Official 1, In formula 1, The equivalent dielectric constant of the metasurface formed by the HMM and ZIM regions is given. Let be the equivalent permeability of the metasurface formed in the HMM region along the x-direction of the structure. Capacitance per unit length Inductance per unit length The dielectric constant of vacuum is . The permeability of vacuum. The equivalent permeability of the metasurface formed in the ZIM region. g is the system's structural factor. ,in and These are the intrinsic impedance and effective wave impedance of the structure, respectively. Angular frequency, , Let be the frequency of the HMM and ZIM regions, and d be the side length of several squares formed by the transverse and longitudinal lines. Given the capacitance value of the first capacitor, we can obtain... The value of , C is the second capacitor.

3. The energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface as described in claim 1, characterized in that, It also includes resistors located on the outermost horizontal and vertical line segments.

4. The energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface as described in claim 1, characterized in that, It also includes at least one excitation source located in the ZIM region.

5. The energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface as described in claim 1, characterized in that, The HMM region is located in the middle of the circuit board.

6. The energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface as described in claim 1, characterized in that, The HMM region is located on either side of the circuit board.

7. The energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface as described in claim 1, characterized in that, The horizontal conductive lines and the vertical conductive lines are arranged at equal intervals.

8. An energy harvesting system based on a hyperbolic scatterer in a zero-refractive-index metasurface as described in any one of claims 1 to 7 can be further used in a wireless power transmission system.

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