Space structure for energy harvesting and manufacturing method therefor

Abstract

Disclosed are a space structure for energy harvesting and a manufacturing method therefor. The space structure for energy harvesting of the present invention comprises: a frame that forms the space structure; and a piezoelectric material that is disposed on the outer surface of the frame and has a piezoelectric effect, wherein when atoms collide with the space structure in space where at least one type of atoms exists, the piezoelectric material can convert collision energy of the atoms into electrical energy.

Description

Space structure for energy harvesting and method for manufacturing the same

[0001] The present invention relates to energy harvesting technology, and more particularly, to a space structure for energy harvesting and a method for manufacturing the same.

[0002] Satellite orbits are classified into Low Earth Orbit (LEO), Medium Earth Orbit (MEO), and Geosynchronous Earth Orbit (GEO) depending on altitude. Low Earth Orbit (LEO) refers to an artificial satellite orbit at an altitude of 300 to 1500 km from the Earth's surface. Satellites located in this low Earth Orbit are exposed to harsh environmental factors such as ultra-high vacuum pressure, high temperature changes (-70 to 80 degrees Celsius), ultraviolet (UV), and atomic oxygen (AO). Among the environmental factors, atomic oxygen (AO) accounts for 80% of the thin atmosphere as shown in Figure 1, and the density of these particles appears to be the result of oxygen being broken down by specific photodissociative radiation wavelengths (100-200 nm) of the sun. The generated atomic oxygen (AO) collides with the surface of an orbiting satellite, with a collision speed of approximately 8 km / s. As a result, the atomic oxygen (AO) has an energy of approximately 5 eV per atom and can cause damage to the spacecraft surface, as shown in Figure 2.

[0003] Meanwhile, the energy sources for satellites and spacecraft in space use radioisotope thermoelectric generators (RTGs) or solar cells due to the extreme environments. RTGs, due to their long lifespan (over 10 years) and high reliability, are suitable for operating large and deep space probes, especially exoplanet probes. However, they generate radiation during the power generation process and consume fuel, making them unsuitable for low Earth orbit environments. Solar panels, however, have high power generation efficiency and account for over 90% of satellite energy sources as of 2021. However, because they rely on solar energy, a continuous energy supply is difficult without direct exposure to the sun.

[0004] Therefore, there is a need to develop a new energy harvesting method that can replace or be used as an auxiliary energy source for RTGs or solar panels used as energy sources for spacecraft or satellites in space.

[0005] An embodiment of the present invention provides a space structure and a manufacturing method for energy harvesting that converts the kinetic energy of an atomic-level collider into electrical energy.

[0006] In addition, an embodiment of the present invention utilizes atomic oxygen (AO) as an energy source in a low-orbit environment, which allows for utilization even in extreme environments where solar panels do not operate, and diversifies energy sources available in space.

[0007] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0008] According to an embodiment of the present invention, a space structure for energy harvesting is provided, comprising: a frame forming the space structure; and a piezoelectric material having a piezoelectric effect, the piezoelectric material being disposed on an outer surface of the frame; and a space structure for energy harvesting that, when atoms collide with the space structure in space where at least one type of atoms exists, the piezoelectric material converts collision energy of the atoms into electrical energy.

[0009] In one embodiment, the atomic type may include at least one of atomic oxygen (AO or ATOX), atomic nitrogen, helium, hydrogen, argon, or galactic cosmic rays (GCR). The piezoelectric material may include at least one of single crystal and polycrystalline ceramics, polymer materials, and composite materials. The single crystal material may be α-AlPO4 (Berlnite), α-SiO2 (Quartz), LiTiO3, LiNbO3, SrxBayNb2O8, Pb5-Ge3O 11 , Tb2(MoO4)3, Li2B4O7, CdS, ZnO, Bi12SiO20, Bi12GeO20, and the polycrystalline material includes at least one of PZT, PT, PZT-Complex Perovskite, and BaTiO3, and the polymer material includes at least one of PVDF, P(VDF-TrFe), P(VDFTeFE), and TGS, and the composite material may include at least one of PZT-PVDF, PZT-Silicon Rubber, PZT-Epoxy, PZT-foam Polymer, and PZT-foam Urethane.

[0010] In one embodiment, a protective layer may be further included to prevent deterioration of the piezoelectric material. The protective layer is in the form of a thin film or film, and the protective layer includes one of a ceramic material and a polymer, and the ceramic material is titanium oxide (TiO2), silicon oxide (SiO2), aluminum oxide (Al2O3), zirconium oxide (ZrO2), silicon carbide (SiC), silicon nitride (SiO x N y ), silicon dioxide (Si A l x O y ), tin oxide (SnO2), zinc tin oxide (Zn x Sn 1-x O y ), niobium oxide (Nb2O5).

[0011] In one embodiment, as the effective flux, which is a value indicating the degree to which the atoms collide per unit area on the surface of the space structure, increases, the electric energy may increase. When the exposure area of ​​the piezoelectric material increases under the same effective flux environment, the voltage of the electric energy may be constant and the current may relatively increase. Even if the thickness of the piezoelectric material increases under the same effective flux environment, the voltage and current of the electric energy hardly change. The space structure is one of an artificial satellite, a spacecraft, and a space station, and the space may be a Low Earth Orbit (LEO) or a Very Low Earth Orbit (VLEO).

[0012] According to another embodiment of the present invention, a method for manufacturing a space structure for energy harvesting is provided, comprising the steps of: preparing a frame forming the space structure; and arranging a piezoelectric material having a piezoelectric effect on an outer surface of the frame, wherein when atoms collide with the space structure in space where at least one type of atoms exists, the piezoelectric material converts collision energy of the atoms into electrical energy.

[0013] In one embodiment, the atomic type may include at least one of atomic oxygen (AO or ATOX), atomic nitrogen, helium, hydrogen, argon, or galactic cosmic rays (GCR). The piezoelectric material may include at least one of single crystal and polycrystalline ceramics, polymer materials, and composite materials. The single crystal material may be α-AlPO4 (Berlnite), α-SiO2 (Quartz), LiTiO3, LiNbO3, SrxBayNb2O8, Pb5-Ge3O 11 , Tb2(MoO4)3, Li2B4O7, CdS, ZnO, Bi12SiO20, Bi12GeO20, and the polycrystalline material includes at least one of PZT, PT, PZT-Complex Perovskite, and BaTiO3, and the polymer material includes at least one of PVDF, P(VDF-TrFe), P(VDFTeFE), and TGS, and the composite material may include at least one of PZT-PVDF, PZT-Silicon Rubber, PZT-Epoxy, PZT-foam Polymer, and PZT-foam Urethane.

[0014] In one embodiment, a protective layer may be further included to prevent deterioration of the piezoelectric material. The protective layer is in the form of a thin film or film, and the protective layer includes one of a ceramic material and a polymer, and the ceramic material is titanium oxide (TiO2), silicon oxide (SiO2), aluminum oxide (Al2O3), zirconium oxide (ZrO2), silicon carbide (SiC), silicon nitride (SiO x N y ), silicon dioxide (Si A l x O y ), tin oxide (SnO2), zinc tin oxide (Zn x Sn 1-x O y ), niobium oxide (Nb2O5).

[0015] According to an embodiment of the present invention, a space structure for energy harvesting can be utilized as a new energy source that serves as an auxiliary energy source for solar panels in use in the past by converting the kinetic energy of an atomic-sized collider into electrical energy, thereby enabling energy to be secured even in spaces not directly exposed to the sun.

[0016] Furthermore, the space structure for energy harvesting of the present invention possesses the characteristic of minimal variation in energy harvested per unit area even when the thickness of the piezoelectric material is reduced. Therefore, it can be manufactured in a thin film form, similar to a solar cell, to achieve high energy harvesting efficiency relative to its weight. Furthermore, when applied, it has a price advantage over other energy sources.

[0017] Figure 1 is a graph showing the density of particles existing in the LEO environment.

[0018] Figure 2 is a drawing showing a spacecraft surface damaged by atomic oxygen (AO).

[0019] FIG. 3 is a drawing for explaining a space structure for energy harvesting according to an embodiment of the present invention.

[0020] Figure 4 is a drawing showing atomic oxygen in low Earth orbit colliding with a piezoelectric material.

[0021] Figure 5 is a drawing showing three different thicknesses of the piezoelectric plate used in the experimental example.

[0022] Figure 6a is a photograph showing test equipment for simulating a low-orbit environment.

[0023] Figure 6b is a schematic diagram showing the configuration of a test device for simulating a low-orbit environment.

[0024] FIGS. 7A to 7C are graphs showing the performance of the piezoelectric effect according to atomic oxygen (AO) collisions according to one embodiment of the present invention.

[0025] FIG. 8 is a graph showing an ion energy distribution function according to height (H) according to one embodiment of the present invention.

[0026] FIG. 9 is a diagram showing changes in average ion energy and ion flux according to height (H) according to one embodiment of the present invention.

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0028] The embodiments of the present invention described below are provided to more clearly explain the present invention to a person having ordinary skill in the art, and the scope of the present invention is not limited by the following embodiments, and the following embodiments can be modified in various other forms.

[0029] The terminology used herein is used to describe particular embodiments and is not intended to limit the present invention. The singular forms used herein may include the plural forms unless the context clearly dictates otherwise. In addition, the terms "comprise" and / or "comprising" used herein specify the presence of a stated feature, step, number, operation, element, element, and / or group thereof, but do not exclude the presence or addition of one or more other features, steps, numbers, operations, elements, elements, and / or groups thereof. In addition, the term "connected" used herein not only means that certain elements are directly connected, but also includes a concept that indirectly connects elements by interposing another element between them.

[0030] In addition, when it is said in this specification that a certain element is located "on" another element, this includes not only cases where a certain element is in contact with another element, but also cases where another element exists between the two elements. The term "and / or" as used in this specification includes any one of the listed items and any and all combinations of one or more of them. In addition, terms of degree such as "about", "substantially", etc. as used in this specification are used to mean a range of or close to the numerical value or degree, taking into account inherent manufacturing and material tolerances, and are used to prevent infringers from unfairly using the disclosure that mentions exact or absolute numbers provided to help the understanding of this specification.

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The sizes and thicknesses of areas or parts illustrated in the attached drawings may be somewhat exaggerated for clarity and convenience of explanation. Like reference numbers designate like components throughout the detailed description.

[0032] The present invention proposes a new form of energy source in a space environment where energy sources are scarce, and in particular, it can convert the ultra-high-speed collision energy of atomic oxygen (AO or ATOX), which occupies most of the thin atmosphere of low Earth orbit (LEO, 300 to 1500 km from the surface), into electrical energy by utilizing a piezoelectric material. Specifically, the present invention converts the kinetic energy of atomic-type colliders colliding at ultra-high speeds in space into electrical energy by utilizing a piezoelectric material, thereby providing a new energy generation mechanism that serves as an auxiliary energy source for solar panels conventionally utilized in space, and can be utilized in the field of space technology.

[0033] According to one embodiment of the present invention, a device for converting kinetic energy of an atomic-type collider into electrical energy by utilizing a piezoelectric material is provided, wherein the surface of a space structure is formed using a material having a piezoelectric effect, atomic oxygen collides with the surface of the structure, and the collision energy is converted into electrical energy.

[0034] In particular, atomic oxygen makes up the majority (80%) of the low-Earth orbit atmosphere. Considering the limitations of solar cells, which account for the majority (over 90%) of satellite energy sources, utilizing the collisional energy of atomic oxygen as an energy source would allow for the construction of a stable and diversified energy infrastructure, rather than relying solely on a single energy source in the low-Earth orbit environment.

[0035] FIG. 3 is a drawing for explaining a space structure for energy harvesting according to an embodiment of the present invention, and FIG. 4 is a drawing illustrating an appearance of atomic oxygen in low Earth orbit colliding with a piezoelectric material.

[0036] Referring to FIG. 3, a space structure (100) for energy harvesting may include a frame (10) forming the space structure (100); and a piezoelectric material (20) having a piezoelectric effect, which is disposed on the outer surface of the frame (10) (a). Without limitation, the frame (10) may be a body forming an artificial satellite, a space shuttle, or a space station, and may be composed of a metal material, a ceramic material, a polymer material, or a mixture or alloy thereof. Preferably, the frame (10) may include copper, aluminum, titanium, nickel, or an alloy thereof as the metal material, and may be a carbon composite material as the ceramic material.

[0037] A piezoelectric material (20) can be coated or deposited on a frame (10), and when atoms collide with the space structure in space where at least one type of atoms exist, the piezoelectric material (20) can convert the collision energy of the atoms into electrical energy. Although not shown, the electrical energy generated in the piezoelectric material (20) can be transmitted to an energy storage device or equipment (not shown) existing inside the space structure through an electrode. The space can be a Low Earth Orbit (LEO) or a Very Low Earth Orbit (VLEO), and the atoms are atoms existing in LEO or VLEO, and the type of atoms can include at least one of atomic oxygen (AO or ATOX), atomic nitrogen, helium, hydrogen, argon, or galactic cosmic rays (GCR).

[0038] In one embodiment, the piezoelectric material (20) is composed of at least one of single crystal and polycrystalline ceramics, polymer materials, and composite materials, and the single crystal material is α-AlPO4 (Berlnite), α-SiO2 (Quartz), LiTiO3, LiNbO3, SrxBayNb2O8, Pb5-Ge3O 11, Tb2(MoO4)3, Li2B4O7, CdS, ZnO, Bi12SiO20, Bi12GeO20, and the polycrystalline material includes at least one of PZT, PT, PZT-Complex Perovskite, and BaTiO3, and the polymer material includes at least one of PVDF, P(VDF-TrFe), P(VDFTeFE), and TGS, and the composite material may include at least one of PZT-PVDF, PZT-Silicon Rubber, PZT-Epoxy, PZT-foamed Polymer, and PZT-foamed Urethane. The thickness range of the piezoelectric material (20) is 0.05 mm to 5.0 mm. If the thickness of the piezoelectric material (20) is less than 0.05 mm, the piezoelectric material may be easily damaged due to collision of atoms, which may lower the energy conversion efficiency, and if the thickness of the piezoelectric material (20) is more than 5.0 mm, the weight of the overall space structure may increase, which may lower the energy efficiency.

[0039] Optionally, the space structure (100) for energy harvesting may have a protective layer (30) deposited or coated on the piezoelectric material (20) to prevent deterioration of the piezoelectric material (20). The deposition or coating method may follow a conventionally disclosed method. The protective layer (30) may be in the form of a thin film or film, and the protective layer may include one of a ceramic-based material and a polymer. The ceramic-based material may be titanium oxide (TiO2), silicon oxide (SiO2), aluminum oxide (Al2O3), zirconium oxide (ZrO2), silicon carbide (SiC), or silicon nitride (SiO). x N y ), silicon dioxide (Si A l x O y ), tin oxide (SnO2), zinc tin oxide (Zn x Sn 1-x O y ), niobium oxide (Nb2O5).

[0040] In the present invention, the value indicating the degree to which the atoms collide per unit area on the surface of the space structure (100) is referred to as effective flux, and in particular, the degree to which oxygen atoms collide per unit area on the surface of the space structure (100) is referred to as effective AO flux.

[0041] Referring to the experimental examples described below, as the effective flux increases, the electric energy converted through the piezoelectric material (20) increases, and when the exposed area of ​​the piezoelectric material (20) increases in the same effective flux environment, the voltage of the electric energy converted through the piezoelectric material (20) is constant and the current relatively increases, so that the overall change in power density is not large. In addition, even if the thickness of the piezoelectric material (20) increases in the same effective flux environment, the voltage and current of the electric energy converted through the piezoelectric material (20) hardly change.

[0042] As described above, the surface of the space structure (100) of the present invention is formed using a material having a piezoelectric effect, and atomic oxygen (hereinafter referred to as AO) collides with the surface of the formed structure, and the collision energy is converted into electric energy, and this electric energy can be used as an energy source for a spacecraft or artificial satellite in space. Preferably, the space may be low earth orbit (hereinafter referred to as LEO) in space at an altitude of 300 to 1500 km from the ground. As described above, the atmosphere at this altitude is mostly distributed with atomic oxygen (AO).

[0043] Referring to Fig. 4, atomic oxygen (AO) collides with a spacecraft moving at approximately 8 km / s, and the collision energy at this time is approximately 5 eV per atom. The value representing the degree to which such atomic oxygen (AO) collides with the spacecraft surface per unit area is called "effective AO flux". This is presented in ASTM E2089-15, a standard of ASTM International, an international standardization organization. Fig. 4 illustrates an image of atomic oxygen in low Earth orbit colliding with a piezoelectric material. It should be noted in advance that the size of the atomic oxygen in the process is exaggerated for the sake of understanding the invention, and the thickness of the piezoelectric material is also expressed for the sake of understanding and may differ from the actual size.

[0044] Fig. 5 is a drawing showing three thicknesses of piezoelectric plates used in an experimental example, Fig. 6a is a photograph showing a test device for simulating a low-orbit environment, and Fig. 6b is a drawing showing a schematic configuration of a test device for simulating a low-orbit environment.

[0045] <Experimental Example>

[0046] * Piezoelectric material

[0047] The piezoelectric material used in the experimental example was PZT (lead zirconate titanate)-5A, purchased from piezo.com. The PZT-5A piezoelectric material has excellent thermal stability between 150°C and 250°C. The characteristics of PZT-5A are shown in [Table 1] below.

[0048] [Table 1]

[0049]

[0050] Referring to Fig. 5, PZT plates with a width and length of 72.4 mm and 72.4 mm, respectively, and three different thicknesses (0.27 mm, 0.51 mm, 1.02 mm) were used in the experiment.

[0051] * Low Earth Orbit Environment Simulation Device

[0052] Referring to Figures 6a and 6b, photographs of the test equipment and detailed experimental setup for simulating the low-orbit environment are shown. As shown in Figure 6a, a high vacuum (10) was created using the 'Space Environment Chamber' at KAIST in Daejeon. -3 Torr) environment was reproduced and experiments were conducted.

[0053] Specifically, a radio frequency (RF) plasma gun was used to generate oxygen plasma to simulate the effects of AO collisions in LEO, and the conditions of the test equipment are as shown in [Table 2] below. The vacuum pressure was 10 -3 The plasma chamber was maintained in a high vacuum range of 10 Torr, and the power input was maintained at approximately 150 W to ensure continuous and stable operation. A retarding field energy analyzer (RFEA) was used to measure ion energy and ion flux density. The RF plasma gun has a frequency of 13.56 MHz and a maximum power of 600 W. In the present experiment, a power of 130 W was used to ensure the stability of the plasma equipment.

[0054] [Table 2]

[0055]

[0056] (1) Adjustment of effective AO flux and height (H in Fig. 6b)

[0057] The following [Mathematical Equation 1] is used to calculate the effective AO flux. The Kapton HN mass defect method is based on the value of the AO reactive coefficient of Kapton HN given in the standard specification, which is 2.81×10 -24 cm 3 / atom is used. Here, the meaning of each variable in [Mathematical Formula 1] is as shown in [Table 3] below.

[0058] [Mathematical Formula 1]

[0059]

[0060] [Table 3]

[0061]

[0062] In Fig. 6(b), H (height) represents the distance from the bottom surface of the vacuum chamber equipment to the bottom surface of the PZT plate. The height (H) is adjusted by a height adjuster, and the effective AO flux was measured at three different heights based on H values ​​of 17 mm, 45 mm, and 70 mm. The weight of the Kapton HN film was measured before and after exposure to the plasma environment. The dimensions of the Kapton HN film are 36.2 mm wide X 72.4 mm long.

[0063] The schematic configuration of the experiment is as shown in Fig. 6(b), and the piezoelectric material is exposed to AO impact. The effective AO flux data listed in [Table 4] confirm that the effective AO flux value increases as the PZT plate is placed higher than the bottom surface and closer to the RF plasma source. This phenomenon occurs because the area affecting the effective flux when AO is irradiated from the exit of the RF plasma source to the bottom plate is larger at the bottom than at the exit of the plasma source. [Table 4] below shows the AO flux calculated by the Kapton HN mass defect.

[0064] [Table 4]

[0065]

[0066] The effective AO flux measured in real low Earth orbit (LEO) environments is 10 12 10 inland 16 atoms / cm 2 s has a range.

[0067] (2) Measurement of ion energy distribution function (IEDF)

[0068] The ion energy distribution function (IEDF) and ion plus in direct contact with the surface were measured in real time using a commercial RFEA (Semion RFEA, Impedans, Ireland) with a 5 mm thick, 50 mm diameter probe. The RFEA probe consists of grids (G0, G1, G2, and G3) and a current collector plate. All grids are made of nickel and feature 20 μm diameter holes with 50% transmittance. Each of the four grids of the RFEA probe performs a specific function. G0 prevents plasma formation within the probe, G1 repels plasma electrons, G2 filters ions according to their energy, and G3 can prevent high-energy ions from emitting secondary electrons in C. The current collector plate, which has a negative potential compared to G0, is used to collect and measure the ion current passing through G2. The RFEA is positioned on a height adjuster together with a Kapton HN film. The ion energy is measured at three different heights based on H values ​​of 17 mm, 45 mm, and 70 mm. The following [Equation 2] is used to calculate the ion flux density, and the following [Equation 3] is used to calculate the average ion energy of the IEDF. The total ion collection area (A) is 1.86 Х 10 5 m 2 and the combined transparency of the probe grid (T) is 0.0625. FIED is the ion energy distribution (IED) obtained by the RFEA probe. E min and E max are the minimum and maximum energies of the distribution, respectively. E Ave is the average energy of the IEDF measured by the RFEA equipment. Here, the meaning of each variable in [Mathematical Formula 2] and [Mathematical Formula 3] is as shown in [Table 5] below.

[0069] [Equation 2]

[0070]

[0071] [Equation 3]

[0072]

[0073] [Table 5]

[0074]

[0075] (3) PZT generation electrical measurement

[0076] When AO impact was applied to the PZT plate, the voltage and current generated in the PZT plate were measured. The method designed to measure the electrical characteristics generated in the PZT plate under AO impact environment is as follows. The electrodes were connected to the top and bottom of the PZT plate through soldering (Top electrode and Bottom electrode in Figs. 5 and 6b). Then, the copper wire connected to each electrode was connected to a part of the vacuum chamber for connecting the electrodes so that the electrical characteristics could be measured while the electrodes were connected to an external oscilloscope. The electrical characteristics of the PZT generated during exposure to AO were measured by connecting the electrodes to an external oscilloscope (DSOX1204G, Key-sight, USA). To ensure uniformity, the RF plasma gun was set to 10 3 The device was operated under 10 Torr conditions and the voltage was measured after 1 minute. The average of the maximum and minimum measured voltages was used for the voltage measurement. The current was measured using the equation voltage drop, using a fixed 1000-ohm metal resistor. The power measurement results are summarized in [Table 6].

[0077] FIGS. 7A to 7C are graphs showing the performance of the piezoelectric effect according to atomic oxygen (AO) bombardment according to an embodiment of the present invention. FIG. 7A is a graph showing power density, voltage, and current values ​​according to different effective AO fluxes, FIG. 7B is a graph showing power density values ​​according to the thickness of a PZT specimen, and FIG. 7C is a photograph of a specimen having three different exposed areas. FIG. 8 is a graph showing an ion energy distribution function according to height (H) according to an embodiment of the present invention, and FIG. 9 is a diagram showing a change in average ion energy and ion flux according to height (H) according to an embodiment of the present invention.

[0078] * Experimental results

[0079] (1) Electrical characteristics of PZT according to effective AO flux

[0080] Referring to Fig. 7a, it is shown that when a piezoelectric material, PZT, is exposed to an ultra-high-velocity AO shock, the electrical response measured in the piezoelectric element increases as the effective flux increases. Fig. 6(a) shows the results of PZT exposure under various effective AO flux conditions. The effective AO flux was varied by adjusting the height 'H' value. These changes in the effective AO flux are listed in the cases of 'H1T2A3', 'H2T2A3', and 'H3T2A3' in [Table 6] below.

[0081] 1) F: Indicates the effective AO flux. F1, F2, F3 are 0.79 x 10 in that order. 16 atoms / cm 2 s, 1.06 x 10 16 atoms / cm 2 s, 1.43 x 10 16 atoms / cm 2 It is s.

[0082] 2) T: Indicates Thickness. T1, T2, T3 represent 0.27mm, 0.51mm, and 1.02mm in that order.

[0083] 3) A: Indicates the area exposed to atomic oxygen collisions. A1, A2, A3 are 1250 mm in order. 2 , 2500 mm 2 , 4937 mm 2 It represents.

[0084] Referring to [Table 6] below, it can be seen that both the voltage and current measured from the piezoelectric element increase as the effective AO flux increases. When the effective AO flux is 0.79 Х 10 16 atoms / cm 2 1.43 Х 10 in s 16 atoms / cm 2 As s increases, the voltage increases from 13.51 V to 17.9 V. Similarly, the current increases from 0.65 mA to 1.07 mA in the same flux range. These results show that the power density, voltage, and current are linearly proportional to the effective AO flux. When the effective AO flux is 0.79 Х 10 16 atoms / cm 2 1.43 Х 10 in s 16 atoms / cm 2 As s increases, the power density increases to 1.78 W / m 2 3.88 W / m 2 increased to .

[0085] (2) Effect of PZT specimen thickness and total number of AO impacts

[0086] The measured electrical output is almost unchanged even when the thickness of the PZT plate is changed. Referring to Figures 7b and 7c, three different specimen thicknesses (0.27 mm, 0.51 mm, 1.02 mm) and three different total AO impact numbers (exposed area: 1250 mm 2 , 2500 mm 2 , 4937 mm 2) for the same 1.43 Х 10 16 atoms / cm 2 The results of exposing the PZT plate under effective AO flux conditions of s are shown. Although the specimen thickness increased approximately two-fold and four-fold, the measured voltage and current did not show any noticeable changes. Referring to [Table 6] below, the voltage values ​​are almost the same under the same effective AO flux conditions. Unlike the voltage values, an increase in the exposed area corresponding to the total number of AO impacts results in a linear increase in the current. Therefore, the power density is essentially constant under the same effective AO flux conditions, regardless of the change in other variables. The measured value is 1.43 Х10 16 atoms / cm 2 Approximately 4 W / m under effective flow conditions of s 2 It has a current density.

[0087] [Table 6]

[0088]

[0089] (3) Measurement of atomic plasma ion energy

[0090] Ion energy measurements were performed to compare the impact velocity of atomic oxygen (AO) within the LEO environment and the plasma state of the instrument. Figure 8 shows the measured IEDF as a function of height (H). As a result, the IEDF exhibits a distinct single peak in ion energy. Moreover, the ion energy peak of the oxygen plasma generated in the instrument occurs within a range of approximately 5 eV. This observation indicates that the energies exhibited by atomic oxygen (AO) present in LEO when it impacts a spacecraft are similar. The measurements were performed at three different heights: 17 mm, 45 mm, and 70 mm, and the values ​​of the ion energy peaks increase with increasing height. Figure 9 also shows the results for various effective AO flux levels. 0.79 Х 10 16 atoms / cm 2 s, 1.13 Х 10 16 atoms / cm2 s, and 1.52 Х 10 16 atoms / cm 2 As the effective AO flux increases, the average energy (7.90 eV, 8.81 eV, 9.30 eV) and ion flux (0.173 A / m 2 , 0.201 A / m 2 , 0.229 A / m 2 ) also increases. In summary, the experimental results show that at the peak plasma state of the device, oxygen has an energy of about 5 eV, and it can be confirmed that as the effective AO flux increases, the average ion energy and flux increase.

[0091] The experimental results described above clearly demonstrate the piezoelectricity during the high-speed collision of atomic oxygen (AO) on the piezoelectric material. As can be seen in Fig. 7a and Table 6 above, it was observed that the power density increased linearly as the effective AO flux increased by adjusting the height (H) of the PZT. Both the voltage and the current increased with the increasing AO flux. On the other hand, when the exposed area corresponding to the total number of AO collisions increases, there is a linear effect only on the current, and accordingly, even if the total number of AO collisions changes, the power density (W / m) does not change as long as the effective AO flux does. 2) shows little change. These results suggest that the voltage output is determined by the AO collision probability per unit area, while the total number of collisions determines the amount of power generated. Even when the exposed area increases, the AO collision probability per unit area remains the same, but the total number of AO collisions, which are the energy source, increases. As the exposed area increases, the current increases and the voltage remains constant. Referring to Fig. 7(b), no noticeable change in power density was observed even when the thickness of the PZT specimen was changed. Since PZT with a perovskite structure exhibits a piezoelectric response due to atomic-level impact, it appears that it can be manufactured very thinly, like an optoelectric perovskite solar cell, and thus achieve high power density. Furthermore, if such a piezoelectric material is applied thinly on the surface of a spacecraft, it seems that it can be used independently or integrated with a solar cell to improve performance.

[0092] Although numerous studies have been conducted on the effects of AO erosion on spacecraft, little research has been conducted on energy harvesting technologies for the impact energy of oxygen atoms (AO), which account for nearly 80% of the LEO environment. The measurement range of effective AO flux in LEO is approximately 10 depending on the flight direction. 16 atoms / cm 2 s. The AO flux is expected to increase further in very low Earth orbit (VLEO), which is lower than LEO and has potential for future applications. 1.43 Х 10 measured in the present experiment 16 atoms / cm 2 Under the effective AO flux conditions, the power density is approximately 4 W / m as shown in [Table 6] above. 2 was measured as

[0093] In the present invention, piezoelectric power generation under AO impact was demonstrated by varying parameters such as the thickness, height, and exposed area of ​​the piezoelectric material. However, piezoelectric power generation may also vary depending on space and environmental factors, including high-vacuum conditions, temperature fluctuations, and exposure to ultraviolet light.

[0094] Meanwhile, the effective AO flux is 0.79 Х 10 16 atoms / cm 2 1.43 Х 10 in s 16 atoms / cm 2 s increased by 81%, resulting in a power density of 1.78 W / m 2 4.24 W / m at 2 The increase in ion flux is approximately 32%. This discrepancy appears to be due to the inability of RFEA to represent the possible combination ratios of oxygen species, and the ion beam scatters and loses energy due to space charge effects. To more reliably evaluate piezoelectric energy harvesting, it is recommended to measure temperature changes and specify the oxygen species involved. The present invention is not limited to energy harvesting by atomic oxygen (AO) collisions. For example, it is also possible by the effect of collisions between neutral atoms.

[0095] Furthermore, the change in power density due to the increase in effective AO flux indicates that piezoelectric materials can be used as plasma measurement sensors. Using the measured power in the piezoelectric material, a real-time AO flux evaluation method similar to quartz crystal microbalance sensors and terahertz heterodyne spectroscopy can be applied. This field can be extended to other piezoelectric materials, such as polyvinylidene fluoride (PVDF), which has been studied for space applications in PZT. Furthermore, its flexibility and mechanical properties allow the use of new piezoelectric polymers and composites that follow the same operating principles. In the present invention, experiments were conducted using PZT, a commonly used piezoelectric material with durable and highly responsive piezoelectric properties. However, the present invention utilizes PVDF to generate energy, allowing mechanical loads such as bending, torsion, and tension. Coatings made of PVDF or other flexible materials could be applied to solar sailing structures, large shells that generate power for ion engines. High altitudes, such as geostationary orbit (GEO) or deep space, are home to numerous high-velocity particles. In the absence of sunlight, the primary energy source, the kinetic energy of these particles could be used as an alternative energy source.

[0096] In addition to the applications mentioned above, embodiments of the present invention may be utilized in the aerospace field or other fields utilizing atomic collisions.

[0097] Embodiments of the present invention recognize that space energy resources are limited, and a method of securing energy through collisions at the atomic scale diversifies energy securing means and can be utilized as a new energy securing means for spacecraft and satellites. For example, it can be utilized as a means of securing energy for spacecraft, like solar cells. Like solar energy, it is a power generation system that does not require additional fuel, so it has the advantage of not requiring a continuous fuel supply. Similar to a solar sail with a large surface area, if a large surface area is composed of piezoelectric materials, more energy can be harvested, and it can be utilized as a new energy securing means that supplements solar energy.

[0098] According to an embodiment of the present invention, electricity is generated from the kinetic energy of an atomic-type collider, and it is utilized as a new energy source that plays an auxiliary role in solar panels in use, thereby resolving the disadvantage of difficulty in securing energy in spaces not directly exposed to the sun.

[0099] Furthermore, according to embodiments of the present invention, there is virtually no change in energy harvested per unit area as the thickness of the piezoelectric material, PZT, decreases. This opens up a wide range of applications, enabling the fabrication of thin-film solar cells and other devices with improved energy harvesting efficiency relative to their weight. This application is expected to significantly increase the competitiveness of the device as an energy source.

[0100] Furthermore, it is anticipated that the piezoelectric energy harvesting by the ultra-high-velocity colliding atomic-type collider according to the embodiment of the present invention is not limited to atomic oxygen, and may be extended to unmentioned elements such as atomic nitrogen and helium, as well as to elements of smaller size such as galactic cosmic rays, since the pressure point effect occurs due to atomic-level collisions.

[0101] This specification has disclosed preferred embodiments of the present invention, and although specific terms have been used, they are used in a general sense only to easily explain the technical contents of the present invention and to assist in understanding the invention, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical concept of the present invention are possible in addition to the embodiments disclosed herein. Therefore, the scope of the invention should not be defined by the described embodiments, but by the technical concept described in the claims.

[0102] The present invention relates to a space structure for energy harvesting and a method for manufacturing the same, and has industrial applicability.

Claims

1. As a space structure for energy harvesting, a frame forming the above space structure; and It is arranged on the outer surface of the above frame and includes a piezoelectric material having a piezoelectric effect; A space structure for energy harvesting in which, when atoms collide with the space structure in space where at least one type of atoms exist, the piezoelectric material converts the collision energy of the atoms into electrical energy.

2. In paragraph 1, A space structure for energy harvesting, wherein the atomic type comprises at least one of atomic oxygen (AO or ATOX), atomic nitrogen, helium, hydrogen, argon, or galactic cosmic rays (GCR).

3. In paragraph 1, A space structure for energy harvesting, wherein the piezoelectric material comprises at least one of single crystal and polycrystalline ceramics, polymer materials, and composite materials.

4. In paragraph 3, The above single crystal material is α-AlPO 4 (Berlnite), α-SiO 2 (Quartz), LiTiO 3 , LiNbO 3 , SrxBayNb 2 O 8 , Pb 5 -Ge 3 O 11 , Tb 2 (MoO 4 ) 3 , Li2B4O7, CdS, ZnO, Bi1 2 SiO 2 0,Bi1 2 GeO 2 Contains at least one of 0, The above polycrystalline materials include PZT, PT, PZT-Complex Perovskite, and BaTiO. 3 Contains at least one of: The above polymer material comprises at least one of PVDF, P(VDF-TrFe), P(VDFTeFE), and TGS, The above composite material is a space structure for energy harvesting comprising at least one of PZT-PVDF, PZT-Silicon Rubber, PZT-Epoxy, PZT-foamed Polymer, and PZT-foamed Urethane.

5. In paragraph 1, A space structure for energy harvesting further comprising a protective layer that prevents deterioration of the piezoelectric material.

6. In paragraph 5, The above protective layer is a space structure for energy harvesting in the form of a thin film or film.

7. In paragraph 5, The above protective layer comprises one of a ceramic series material and a polymer, The above ceramic series material is titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), silicon carbide (SiC), silicon nitride (SiO x N y ), silicon dioxide aluminum (Si A l x O y ), tin oxide (SnO 2 ), zinc tin oxide (Zn x Sn 1-x O y ), niobium oxide (Nb 2 O 5 ) for energy harvesting. A space structure comprising at least one of:

8. In paragraph 1, A space structure for energy harvesting in which the electric energy increases as the effective flux, which is a value representing the degree to which the atoms collide per unit area on the surface of the space structure, increases.

9. In paragraph 1, A space structure for energy harvesting in which the voltage of the electric energy is constant and the current relatively increases as the exposure area of ​​the piezoelectric material increases in the same effective flux environment.

10. In paragraph 1, A space structure for energy harvesting in which the voltage and current of the electric energy are hardly changed even when the thickness of the piezoelectric material increases in the same effective flux environment.

11. In paragraph 1, The above space structure is a space structure for energy harvesting, one of artificial satellites, spacecraft, and space stations.

12. In paragraph 1, The above space is a space structure for energy harvesting in low Earth Orbit (LEO) or very low Earth Orbit (VLEO).

13. A method for manufacturing a space structure for energy harvesting as described in Article 1, A step of preparing a frame forming the above space structure; and Comprising a step of arranging a piezoelectric material having a piezoelectric effect on the outer surface of the frame, A method for manufacturing a space structure for energy harvesting, wherein the piezoelectric material converts collision energy of the atoms into electrical energy when the atoms collide with the space structure in space where at least one type of atoms exists.

14. In paragraph 13, A method for manufacturing a space structure for energy harvesting, wherein the atomic type comprises at least one of atomic oxygen (AO or ATOX), atomic nitrogen, helium, hydrogen, argon, or galactic cosmic rays (GCR).

15. In paragraph 13, The above piezoelectric material includes at least one of single crystal and polycrystalline ceramics, polymer materials, and composite materials. The above single crystal material is α-AlPO 4 (Berlnite), α-SiO 2 (Quartz), LiTiO 3 , LiNbO 3 , SrxBayNb 2 O 8 , Pb 5 -Ge 3 O 11 , Tb 2 (MoO 4 ) 3 , Li2B4O7, CdS, ZnO, Bi1 2 SiO 2 0,Bi1 2 GeO 2 Contains at least one of 0, The above polycrystalline materials include PZT, PT, PZT-Complex Perovskite, and BaTiO. 3 Contains at least one of: The above polymer material comprises at least one of PVDF, P(VDF-TrFe), P(VDFTeFE), and TGS, A method for manufacturing a space structure for energy harvesting, wherein the composite material comprises at least one of PZT-PVDF, PZT-Silicon Rubber, PZT-Epoxy, PZT-foamed Polymer, and PZT-foamed Urethane.

16. In paragraph 13, Further comprising a step of forming a protective layer to prevent deterioration of the piezoelectric material; The above protective layer comprises one of a ceramic series material and a polymer, The above ceramic series material is titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), silicon carbide (SiC), silicon nitride (SiO x N y ), silicon dioxide aluminum (Si A l x O y ), tin oxide (SnO 2 ), zinc tin oxide (Zn x Sn 1-x O y ), niobium oxide (Nb 2 O 5 ) A method for manufacturing a space structure for energy harvesting comprising at least one of the following.

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