Paper folding type piezoelectric energy collector for collecting low-frequency energy

Abstract

The invention discloses a paper folding type piezoelectric energy collector for collecting low-frequency energy. The paper folding type piezoelectric energy collector comprises a piezoelectric composite material paper folding cylindrical structure and two side end faces. The piezoelectric composite material origami cylindrical structure is obtained by bending and folding a planar piezoelectric composite material along a peak fold line and a valley fold line. In the bending process, the bent piezoelectric ceramic composite material can be manufactured by controlling external force in the sintering process. According to the invention, piezoelectric ceramic 3D printing is combined with a novel material inspired by paper folding. The piezoelectric ceramic suspension is used as 3D printing ink. The novel material structure is based on a Kresling origami cylindrical surface, but creases are hidden, the effective collection area is increased, and the electrical performance is improved. The multi-stable Kresling origami structure has low rigidity and a low energy barrier, so that energy collection in a low-frequency environment becomes possible, and the multi-stable Kresling origami structure is particularly suitable for ocean wave energy collection application.

Description

Technical Field

[0001] The invention relates to the technical field of low-frequency piezoelectric energy collection, in particular to an origami-type piezoelectric energy collector for low-frequency energy collection. Background Art

[0002] Ocean energy, including waves, tides and currents, is a clean, renewable and abundant energy source with higher energy density than other renewable energy sources. Waves, especially in their main form, have unique characteristics such as low frequency, multi-direction and large amplitude. However, there are challenges in coupling wave motion with energy generation due to difficulties in offshore mooring, harsh marine environment, high construction costs and complex design structures. The introduction of high-performance polymer materials with low density, high energy density and good electromagnetic coupling effect has great potential in wave energy harvesting. The origami-inspired piezoelectric energy harvester provides an innovative solution and rich functional characteristics for utilizing wave motion with irregular directions and frequencies.

[0003] Compared with traditional strategies, origami-inspired designs can enhance mechanical properties without introducing new components or materials due to their unique geometric topologies, such as tunable Poiseu ratio, coupled compression-torsion response, tunable thermal expansion, and tunable stiffness. These properties are particularly promising for flexible, smart industrial structures. However, piezoelectric energy harvesting using origami configurations is often limited to exploiting the deformation of valley and ridge creases. The deformation of these creases is difficult to use for brittle piezoelectric ceramics. Therefore, there is an urgent need to design a piezoelectric energy harvester that can be used at low frequencies and can fully exploit the multi-stable, tunable stiffness mechanical characteristics of origami-type materials. Summary of the invention

[0004] The object of the present invention is to provide an origami-type piezoelectric energy harvester for low-frequency energy collection to solve the problems raised by the above-mentioned background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: an origami-type piezoelectric energy collector for low-frequency energy collection, characterized in that it comprises an upper force-bearing end face, a piezoelectric composite material origami cylindrical structure and a lower force-bearing end face, wherein the upper force-bearing end face and the lower force-bearing end face are respectively attached and bonded to the upper end face and the lower end face of the piezoelectric composite material origami cylindrical structure; The piezoelectric composite material origami cylindrical structure adopts a Kresling origami structure, the unfolded plane is a parallelogram, mountain folding is performed along the mountain folds, valley folding is performed along the valley folds, and a triangular end face area is formed.

[0006] Preferably, the mountain creases and valley creases of the piezoelectric composite origami cylindrical structure are hidden creases with curved arcs, and the value of the average radius of curvature near the mountain creases and valley creases / the radius of the cylindrical end face is 0.25.

[0007] Preferably, the triangular end face region presents a smaller curvature, and the value of the average curvature radius near the triangular end face region / the cylindrical end face radius is 2.

[0008] Preferably, the material of the piezoelectric composite origami cylindrical structure is a piezoelectric ceramic composite material.

[0009] Preferably, the preparation method of the piezoelectric composite origami cylindrical structure is: Step 1: synthesizing BaTiO3 particles for 3D printing ink using a hydrothermal method; Step 2, combining BaTiO3 powder with PVDF powder and DMF to form a ceramic suspension; Step 3, transferring the ceramic suspension into a printing cartridge by mixing and stirring, and printing the unfolded planar structure of the piezoelectric composite origami cylindrical structure using a 3D printer; Step 4, drying the unfolded planar structure of the printed piezoelectric composite material origami cylindrical structure at high temperature; Step 5, placing the unfolded planar structure of the piezoelectric composite origami cylindrical structure prepared in step 4 on an alumina tube and sintering it in a muffle furnace, the sample was initially heated to 600° C. for 2 hours to evaporate the binder; Step 6, sintering at 1320°C for 2 hours; Step 7: After cooling, hidden mountain creases and valley creases with a certain curvature are obtained; Step eight, perform mountain folding along the mountain creases and valley folding along the valley creases to form a piezoelectric composite origami cylindrical structure.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. Compared with other piezoelectric energy harvesting devices, the present invention can respond to multi-directional excitation and capture low-frequency kinetic energy from vertical or horizontal tension, compression and torsion.

[0011] 2. Compared with other piezoelectric energy harvesting devices, the new origami structure used in the present invention greatly increases the deformation under the same pressure, is more sensitive to energy income and deformation, and has a higher power density.

[0012] 3. The present invention improves the flexibility and deformation ability of the material through the folding process. This structure is light and compact, suitable for sea surface floating equipment, so that the energy collector can provide power for small marine equipment.

[0013] 4. The present invention has strong programmability and can adjust the monostable / bistable state of the piezoelectric energy harvester by changing geometric parameters.

[0014] 5. The stiffness of the present invention is adjustable, and different memory states and stiffness can be achieved by compressing / stretching the end surface or rotating the middle.

[0015] 6. The present invention has high durability, and the electrical and mechanical properties remain stable after being folded multiple times. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a three-dimensional schematic diagram of the origami-type piezoelectric composite material of the present invention after folding; Figure 3 It is a plan view schematically showing the unfolded surface of the origami-type piezoelectric composite material of the present invention; Figure 4 It is a schematic diagram of the end face pressure structure of the present invention.

[0017] In the figure: 1, upper force-bearing end face; 2, piezoelectric composite origami cylindrical structure; 3, lower force-bearing end face; 2a, triangular end face area; 2b, valley crease; 2c, mountain peak crease; 2d, upper end face; 2e, lower end face. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 1-4 The present invention provides a technical solution, an origami-type piezoelectric energy collector for low-frequency energy collection, comprising an upper force-bearing end face 1, a piezoelectric composite origami cylindrical structure 2 and a lower force-bearing end face 3, wherein the upper force-bearing end face 1 and the lower force-bearing end face 3 are respectively attached and bonded to the upper end face 2d and the lower end face 2e of the piezoelectric composite origami cylindrical structure 2; The piezoelectric composite origami cylindrical structure 2 adopts a Kresling origami structure, the unfolded plane is a parallelogram, the mountain folding is performed along the mountain fold 2c, the valley folding is performed along the valley fold 2b, and a triangular end face area 2a is formed.

[0020] Furthermore, the peak crease 2c and the valley crease 2b of the piezoelectric composite origami cylindrical structure 2 are hidden creases with curved arcs, and the value of the average curvature radius near the peak crease 2c and the valley crease 2b / the cylindrical end face radius is 0.25. During the folding process, the strain will not be concentrated on the peak crease 2c and the valley crease 2b line, but in the area near the peak crease 2c and the valley crease (2b).

[0021] Furthermore, the triangular end surface area 2a presents a smaller curvature, and the value of the average radius of curvature near the triangular end surface area 2a / the radius of the cylindrical end surface is 2. During the folding process, the pressure of the small deformation at the crease can be shared.

[0022] Furthermore, the material of the piezoelectric composite origami cylindrical structure 2 is a piezoelectric ceramic composite material.

[0023] Furthermore, the preparation method of the piezoelectric composite origami cylindrical structure 2 is: Step 1: synthesizing BaTiO3 particles for 3D printing ink using a hydrothermal method; Step 2, combining BaTiO3 powder with PVDF powder and DMF to form a ceramic suspension; Step 3, transferring the ceramic suspension into a printing cartridge by mixing and stirring, and printing the unfolded planar structure of the piezoelectric composite origami cylindrical structure 2 by a 3D printer; Step 4, drying the unfolded planar structure of the printed piezoelectric composite material origami cylindrical structure 2 at high temperature; Step 5, placing the unfolded planar structure of the piezoelectric composite origami cylindrical structure 2 prepared in step 4 on an alumina tube and sintering it in a muffle furnace, the sample is initially heated to 600° C. for 2 hours to evaporate the binder; Step 6, sintering at 1320°C for 2 hours; Step 7: After cooling, hidden mountain folds 2c and valley folds 2b with a certain curvature are obtained; Step eight, performing mountain folding along the mountain folds 2c and valley folding along the valley folds 2b to form a piezoelectric composite origami cylindrical structure 2.

[0024] Working principle: The excitation signal acts on the upper force-bearing end face 1, causing the origami-type piezoelectric composite cylindrical structure 2 to fold and deform, causing a violent deformation of the piezoelectric composite near the peak crease 2c and the valley crease 2b and a small deformation near the triangular end face 2a. The piezoelectric effect of the piezoelectric composite generates electric charge, the size of which is related to the deformation size of the piezoelectric composite origami cylindrical structure 2. The generated charge is used as the collected energy of the origami-type piezoelectric energy collector for low-frequency energy collection, and the electric energy is stored in the battery when connected to the storage battery.

[0025] Compared with traditional bistable structures, the energy barrier of the bistable Kresling unit is lower. This makes it possible to achieve inter-well motion at lower frequencies and accelerations. When the origami structure 2 moves between different wells, the vibration is chaotic motion and the voltage output can be greatly enhanced. The proposed origami-type piezoelectric composite cylindrical structure 2 can adjust its vibration isolation range by adopting different memories, which can be achieved by compressing / stretching the end faces or rotating them. The use of flexible multi-stable mechanisms enables the system to switch between near-zero stiffness and high stiffness states, effectively turning the stiffness off and on.

[0026] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An origami-type piezoelectric energy harvester for low-frequency energy harvesting, characterized in that: It comprises an upper force-bearing end surface (1), a piezoelectric composite material origami cylindrical structure (2) and a lower force-bearing end surface (3), wherein the upper force-bearing end surface (1) and the lower force-bearing end surface (3) are respectively attached and bonded to an upper end surface (2d) and a lower end surface (2e) of the piezoelectric composite material origami cylindrical structure (2); The piezoelectric composite material origami cylindrical structure (2) adopts a Kresling origami structure, the unfolded plane is a parallelogram, mountain folding is performed along the mountain folds (2c), and valley folding is performed along the valley folds (2b), thereby forming a triangular end face area (2a).

2. The origami-type piezoelectric energy harvester for low-frequency energy collection according to claim 1, characterized in that: The peak crease (2c) and the valley crease (2b) of the piezoelectric composite material origami cylindrical structure (2) are hidden creases with curved arcs, and the value of the average curvature radius near the peak crease (2c) and the valley crease (2b) / the cylindrical end face radius is 0.

25.

3. The origami-type piezoelectric energy harvester for low-frequency energy collection according to claim 1, characterized in that: The triangular end surface area (2a) presents a relatively small curvature, and the value of the average curvature radius near the triangular end surface area (2a) / the cylindrical end surface radius is 2.

4. The origami-type piezoelectric energy harvester for low-frequency energy collection according to claim 1, characterized in that: The material of the piezoelectric composite material origami cylindrical structure (2) is a piezoelectric ceramic composite material.

5. The origami-type piezoelectric energy harvester for low-frequency energy collection according to claim 1, characterized in that: The preparation method of the piezoelectric composite origami cylindrical structure (2) is as follows: Step 1: synthesizing BaTiO3 particles for 3D printing ink using a hydrothermal method; Step 2, combining BaTiO3 powder with PVDF powder and DMF to form a ceramic suspension; Step 3, transferring the ceramic suspension into a printing cartridge by mixing and stirring, and printing the unfolded planar structure of the piezoelectric composite origami cylindrical structure (2) using a 3D printer; Step 4, drying the unfolded planar structure of the printed piezoelectric composite material origami cylindrical structure (2) at high temperature; Step 5, placing the unfolded planar structure of the piezoelectric composite origami cylindrical structure (2) prepared in step 4 on an alumina tube and sintering it in a muffle furnace, the sample is initially heated to 600° C. for 2 hours to evaporate the binder; Step 6, sintering at 1320°C for 2 hours; Step 7: After cooling, hidden mountain creases (2c) and valley creases (2b) with a certain curvature are obtained; Step eight, performing mountain folding along the mountain folds (2c), and performing valley folding along the valley folds (2b), to form a piezoelectric composite origami cylindrical structure (2).

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