An additive manufactured leaf-imitated tri-source composite energy harvesting device

Abstract

This invention provides an additively manufactured leaf-like three-source composite energy harvesting device, belonging to the field of new energy and self-powered technology. The device includes a leaf-vein-like support substrate integrally formed by 3D printing, and integrated on it a droplet triboelectric unit, a piezoelectric conversion unit, and a photovoltaic conversion unit. Liquid-guided stripes on the surface of the leaf-vein-like support substrate optimize droplet spreading. The droplet triboelectric unit captures the mechanical energy of the droplet through the triboelectric effect of the bottom electrode, the triboelectric dielectric layer, and the top electrode. The piezoelectric conversion unit converts the substrate vibration into electrical energy. The photovoltaic conversion unit efficiently collects solar energy. These three units work together to achieve synchronous or time-sharing capture of the droplet impact mechanical energy and solar energy, and output stable electrical energy through a power management circuit. This invention features a compact structure, high integration, and simple fabrication process. It can operate in all weather conditions and is suitable for long-term self-powered scenarios such as IoT terminals, distributed sensor network nodes, and wearable electronic devices.

Description

Technical Field

[0001] This invention relates to the fields of new energy and self-powered technology, and in particular to an additively manufactured leaf-like three-source composite energy harvesting device. Background Technology

[0002] With the rapid development of the Internet of Things (IoT), distributed sensor networks, and wearable electronic devices, higher demands are being placed on the continuity, environmental adaptability, and integration of their power supply methods. While single energy harvesting technologies, such as triboelectric nanogenerators, piezoelectric nanogenerators, and solar cells, can extract mechanical energy, vibrational energy, and light energy from the environment respectively, they are all limited by the intermittency of energy sources and the variability of environmental conditions. For example, triboelectric and piezoelectric technologies rely on mechanical excitations such as droplets and vibrations, resulting in interrupted output under windless and rainless conditions; photovoltaic technology fails at night or in low-light environments. Therefore, developing composite energy harvesting devices capable of synergistically harvesting multiple environmental energy sources has become a key direction for achieving all-weather, sustainable micro-energy supply.

[0003] Currently, research has attempted to combine two energy harvesting mechanisms, such as triboelectric-photovoltaic and piezoelectric-photovoltaic composite devices. However, existing composite devices mostly employ simple physical superposition or discrete combinations, failing to achieve integrated structure-function design. This results in low device integration, insufficient space utilization, limited energy synergy conversion efficiency, and difficulty in achieving high-efficiency simultaneous capture of multiple energy sources within a limited area. Furthermore, existing composite devices lack biomimetic optimization of energy transfer paths in real-world environments in their structural design, leaving significant room for improvement in the capture and conversion efficiency of diffuse energy sources such as droplets. Summary of the Invention

[0004] The core objective of this invention is to overcome the environmental limitations of existing single-energy harvesting devices and the low integration and poor synergy efficiency of dual-mechanism composite devices. It provides a compact, highly efficient, and stable additive manufacturing device based on a leaf-like structure, capable of all-weather operation and low-cost, scalable fabrication. Through biomimetic structural design and multi-mechanism integration, it achieves efficient synchronous or time-sharing collection of droplet kinetic energy (through triboelectric and piezoelectric dual conversion) and solar energy (through photovoltaic conversion), significantly improving the spatiotemporal coverage and output stability of energy harvesting. Simultaneously, it leverages the advantages of low device fabrication cost, simple process, and ease of large-scale production, achieving efficient, stable, and durable multi-source energy harvesting and supply to meet the long-term autonomous power supply needs of IoT terminals and other devices.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An additively manufactured leaf-like three-source composite energy harvesting device includes a leaf vein-like support substrate, a droplet triboelectric unit, a piezoelectric conversion unit, and a photovoltaic conversion unit, which are integrated or spatially coupled from bottom to top. The components work together to capture and convert multi-source energy.

[0007] The leaf vein-like support base is integrally formed using polymer material through 3D printing technology. The surface is provided with leaf vein-like liquid guiding stripes to guide droplets, and it is also provided with a cantilever beam structure and photovoltaic unit fixing groove.

[0008] The droplet triboelectric unit is integrated on the front side of the leaf vein-like support substrate, and from bottom to top includes a bottom electrode, a triboelectric dielectric layer and a top electrode.

[0009] The piezoelectric conversion unit is integrated below the cantilever beam structure of the leaf vein-like support substrate and is used to convert the vibration of the substrate caused by droplet impact into electrical energy.

[0010] The photovoltaic conversion unit is integrated into the light-receiving surface of the device, specifically located in the photovoltaic unit fixing groove hollowed out below the leaf vein-like support substrate.

[0011] Furthermore, the polymer material used for the leaf vein-like support substrate is one of polycarbonate (PC), polylactic acid (PLA), or thermoplastic polyurethane elastomer (TPU). It is integrally formed using fused deposition modeling (FDM) 3D printing technology to form a support substrate with leaf vein-like characteristics. The printing temperature is 260℃-280℃, the printing speed is 200mm / s-280mm / s, and the layer thickness is 0.08mm-0.2mm.

[0012] Furthermore, the bottom electrode of the droplet triboelectric unit is prepared by spraying conductive silver paint with a thickness controlled at 80μm-120μm, preferably 100μm. During the spraying process, the spraying angle is strictly controlled at 45° and the spraying distance is 15cm to ensure that the electrode conformally fits the leaf vein-like substrate surface and that the charge transfer is stable.

[0013] Furthermore, the triboelectric layer of the droplet triboelectric unit is made of polytetrafluoroethylene propylene (FEP) film, which is bonded to the surface of the bottom electrode through a pre-tensioning process. The thickness is 40μm-60μm, preferably 50μm, to ensure that the film is flat and wrinkle-free, so as to maximize the triboelectric contact area.

[0014] Furthermore, the top electrode of the droplet triboelectric unit is attached to the surface of the FEP film with conductive aluminum tape, with a width of 0.1mm-0.5mm, preferably 0.1mm, to ensure efficient contact with the droplet and form a triboelectric effect.

[0015] Furthermore, the piezoelectric conversion unit uses a PZT-5H piezoelectric sheet, which is attached to the fixed end surface of the cantilever beam with 3M CA40H quick-drying adhesive and electrodes are led out. The geometric parameters of the piezoelectric cantilever beam (length 5mm-9mm, thickness 0.5mm-0.9mm) and the substrate material (PLA / PC / TPU) can be matched and optimized with the mechanical impedance according to the expected droplet release frequency (4Hz-8Hz) to maximize the vibration-to-electrical energy conversion efficiency.

[0016] Furthermore, the photovoltaic conversion unit uses a silicon-based solar panel, which is fixed to the base frame by bonding. Positive and negative electrodes are led out and encapsulated and insulated with epoxy resin. The curing temperature is 80°C and the curing time is 2 hours to avoid rain and moisture affecting its performance.

[0017] Furthermore, the overall tilt angle of the device is adjustable, with an adjustment range of 0°-90°. It can be dynamically optimized according to the sunlight angle and droplet descent direction in the actual application scenario, thereby improving the droplet impact effect and sunlight incident efficiency. The device is also equipped with an integrated power management circuit, which is used to combine, stabilize, store energy, and manage the pulsed output of the triboelectric unit and the piezoelectric conversion unit with the DC output of the photovoltaic conversion unit, so as to achieve stable and continuous power output.

[0018] This invention proposes an additively manufactured leaf-like three-source composite energy harvesting device. It utilizes a 3D-printed, one-piece leaf-vein-like support substrate, and integrated droplet triboelectric unit, piezoelectric conversion unit, and photovoltaic conversion unit. The liquid-guided stripes on the leaf-vein-like support substrate surface optimize droplet spreading. The droplet triboelectric unit captures the droplet's mechanical energy through the triboelectric effect of the bottom electrode, triboelectric dielectric layer, and top electrode. The piezoelectric conversion unit converts substrate vibration into electrical energy. The photovoltaic conversion unit efficiently collects solar energy. These three units work together to achieve synchronous or time-sharing capture of droplet impact mechanical energy and solar energy, which are then output as stable electrical energy via a power management circuit. Compared with existing technologies, this invention has the following beneficial technical effects:

[0019] With a wide range of energy sources and all-weather operation: Through the synergy of triboelectric, piezoelectric and photovoltaic mechanisms, it can capture mechanical energy (droplets, vibration) and solar energy in all weather and multiple scenarios, which greatly improves the continuity and reliability of energy supply.

[0020] Biomimetic structure for improved efficiency: The biomimetic leaf vein structure optimizes both droplet spreading (enhancing triboelectric output) and cantilever beam structure stiffness (transmitting vibration to the piezoelectric unit), and can provide an integration platform for photovoltaic units, achieving deep synergy of multiple mechanisms at the structural level and efficient use of space.

[0021] High integration and easy application: Utilizing advanced manufacturing technologies such as 3D printing, multifunctional integrated fabrication is achieved, resulting in compact, lightweight, and flexible device structures that are easy to deploy on various surfaces (such as building exteriors, tents, and vehicle roofs).

[0022] Stable output and easy management: The pulsed triboelectric / piezoelectric output and DC photovoltaic output can be effectively combined, regulated and stored through integrated power management circuitry to provide a stable power output. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is an exploded view of the structure of an additively manufactured leaf-like three-source composite energy harvesting device provided in an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the overall structure of an additively manufactured leaf-like three-source composite energy harvesting device provided in an embodiment of the present invention;

[0026] Figure 3 This is a physical diagram of the overall structure of an additively manufactured leaf-like three-source composite energy harvesting device provided in an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the piezoelectric, triboelectric, and photovoltaic voltage output performance of the leaf-inspired three-source composite energy harvesting device provided in this embodiment of the invention;

[0028] Figure 5 This is a schematic diagram of the piezoelectric and triboelectric voltage output performance of the leaf-inspired three-source composite energy harvesting device provided in this embodiment of the invention under different placement angles;

[0029] Figure 6 This is a schematic diagram of the piezoelectric and triboelectric voltage output performance of the leaf-inspired three-source composite energy harvesting device provided in this embodiment of the invention at different droplet release heights;

[0030] Figure 7 This is a schematic diagram of the piezoelectric and triboelectric voltage output performance of the leaf-inspired three-source composite energy harvesting device provided in this embodiment of the invention at different droplet release frequencies.

[0031] Figure labeling: 1-Imitation leaf vein support substrate; 2-FEP thin film; 3-Top electrode; 4-PZT-5H piezoelectric sheet; 5-Silicon-based solar panel. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In nature, plant leaves are a highly efficient and multifunctional energy conversion platform. Their vein network not only provides mechanical support for the leaves but also guides water transport, enhances light capture, and generates micro-vibrations by utilizing raindrop impacts. Inspired by this, this invention proposes an additively manufactured leaf-inspired three-source composite energy harvesting device. By applying the biomimetic leaf vein structure to the design of the composite energy harvesting device, the energy transfer path is optimized through structural biomimicry. This is expected to achieve deep synergy between multiple energy conversion mechanisms in terms of structure and function, breaking through the performance bottleneck of existing composite devices.

[0034] An additively manufactured leaf-inspired three-source composite energy harvesting device, such as... Figure 1 As shown, it includes a leaf vein-like support substrate 1, a droplet triboelectric unit, a piezoelectric conversion unit, and a photovoltaic conversion unit, which are integrated or spatially coupled from bottom to top. Each component works together to capture and convert energy from multiple sources.

[0035] The leaf vein-inspired support substrate 1 is integrally formed using polymer material through 3D printing technology. Its surface features leaf vein-inspired liquid-guiding stripes to guide droplets, and it also includes a cantilever beam structure and photovoltaic unit fixing grooves. The polymer material used in the leaf vein-inspired support substrate 1 is one of polycarbonate (PC), polylactic acid (PLA), or thermoplastic polyurethane elastomer (TPU), preferably polycarbonate (PC). It is integrally formed using fused deposition modeling (FDM) 3D printing technology to form a support substrate with leaf vein-inspired characteristics. The printing temperature is 260℃-280℃, the printing speed is 200mm / s-280mm / s, and the layer thickness is 0.08mm-0.2mm.

[0036] The droplet triboelectric unit is integrated on the front side of the leaf vein-inspired support substrate 1. From bottom to top, it includes a bottom electrode, a triboelectric dielectric layer, and a top electrode 3. The bottom electrode is prepared by spraying conductive silver paint with a thickness controlled at 80μm-120μm, preferably 100μm. During the spraying process, the spraying angle is strictly controlled at 45° and the spraying distance is 15cm to ensure that the electrode conformally adheres to the surface of the leaf vein-inspired support substrate 1 and that charge transfer is stable. The triboelectric dielectric layer is made of polytetrafluoroethylene propylene (FEP) film 2, which is pre-tensioned and adhered to the surface of the bottom electrode with a thickness of 40μm-60μm, preferably 50μm, to ensure that the film is flat and wrinkle-free, so as to maximize the triboelectric contact area. The top electrode 3 is adhered to the surface of the FEP film 2 with conductive aluminum tape with a width of 0.1mm-0.5mm, preferably 0.1mm, to ensure efficient contact with the droplet and the formation of a triboelectric effect.

[0037] The piezoelectric conversion unit is integrated under the cantilever beam structure of the leaf vein-inspired support substrate 1. It is used to convert the vibration of the substrate caused by droplet impact into electrical energy. The piezoelectric conversion unit adopts PZT-5H piezoelectric sheet 4. PZT-5H is a typical lead zirconate titanate piezoelectric ceramic. It is attached to the fixed end surface of the cantilever beam with 3M CA40H super glue and leads out electrodes. The geometric parameters of the piezoelectric cantilever beam array (length 5mm-9mm, thickness 0.5mm-0.9mm) and substrate material (PLA / PC / TPU) can be matched and optimized with mechanical impedance according to the expected droplet release frequency (4Hz-8Hz) to maximize the vibration-to-electrical energy conversion efficiency.

[0038] The photovoltaic conversion unit is integrated into the light-receiving surface of the device. Specifically, it is located in the photovoltaic unit fixing groove hollowed out below the leaf vein-like support base 1. The photovoltaic conversion unit adopts a silicon-based solar panel 5, which is fixed to the base frame by bonding. The positive and negative electrodes are led out and epoxy resin encapsulation and insulation treatment is carried out. The curing temperature is 80℃ and the curing time is 2 hours to avoid rain and moisture affecting its performance.

[0039] The overall structure of the device is as follows Figure 2 As shown, the overall tilt angle of the device is adjustable, with an adjustment range of 0°-90°. This allows for dynamic optimization based on the sunlight angle and droplet descent direction in the actual application scenario, simultaneously improving droplet impact effect and sunlight incidence efficiency. The device also features an integrated power management circuit for merging, regulating, storing energy, and managing the pulsed outputs of the triboelectric and piezoelectric conversion units and the DC output of the photovoltaic conversion unit, achieving stable and continuous power output. A physical diagram of the device's overall structure is shown below. Figure 3 As shown.

[0040] This embodiment also provides a method for fabricating an additively manufactured leaf-inspired three-source composite energy harvesting device, comprising the following steps:

[0041] Step 1: 3D Model Design and Substrate Printing. Using 3D modeling software such as SolidWorks, a leaf vein-like structural frame with a cantilever beam structure is designed, namely the leaf vein-like support substrate 1 (including leaf vein-like liquid guide stripes, piezoelectric unit mounting positions, and photovoltaic unit fixing grooves). Parameters such as leaf vein density and cantilever beam dimensions are optimized according to application requirements. The selected polymer material (PC / PLA / TPU, preferably PC) is printed using fused deposition modeling (FDM) 3D printing technology to create the leaf vein-like structural frame according to the designed 3D model. Key parameters are strictly controlled during the printing process: printing temperature 260℃-280℃ (preferably 280℃ for PC material), printing speed 200mm / s-280mm / s (preferably 280mm / s), and layer thickness 0.08mm-0.2mm (preferably 0.08mm) to ensure structural accuracy and mechanical properties.

[0042] Step 2: Piezoelectric unit assembly. Grind and polish the surface of the structural frame obtained in Step 1. Use 3M super glue CA40H to attach the PZT-5H piezoelectric sheet 4 to the lower surface of the fixed end of the cantilever beam, ensuring a firm bond and no air bubbles. Lead out the positive and negative electrodes of the piezoelectric sheet and use heat shrink tubing for insulation protection.

[0043] Step 3: Preparation of the bottom electrode of the triboelectric unit. Conductive silver paint is uniformly sprayed onto the front side of the printed leaf vein-like main structure (including the side with the leaf vein-like liquid guiding stripes) to form the bottom electrode of the triboelectric part. During spraying, the paint layer thickness is controlled to be 80μm-120μm (preferably 100μm). By optimizing parameters such as the spraying angle of 45° and the spraying distance of 15cm, the uniform conductivity of the electrode is ensured, and excessively thick paint layers are avoided from affecting the structural flexibility or increasing costs.

[0044] Step 4: Triboelectric layer assembly. A 50μm thick FEP film 2 is bonded to the bottom electrode using a pre-tensioning process with high-temperature resistant double-sided adhesive, ensuring that the film is flat and wrinkle-free, tightly bonded to the bottom electrode, and free of bubbles or gaps.

[0045] Step 5: Preparation of the top electrode 3 of the triboelectric unit. Cut conductive aluminum tape to a preset width (0.1mm-0.5mm) and stick it on the surface of the FEP film 2 to form the top electrode 3, ensuring that the top electrode 3 has good conductivity and strong adhesion to the FEP film 2.

[0046] Step 6: Photovoltaic unit assembly and insulation treatment. Fix the silicon-based solar panel 5 in the light-receiving surface fixing groove of the imitation leaf vein support base 1 (below the liquid guide stripes of the imitation leaf vein), and lead out the positive and negative electrode wires; use epoxy resin to seal and insulate the wire interface and the edge of the solar panel, with a curing temperature of 80℃ and a curing time of 2 hours to ensure waterproof and moisture-proof performance.

[0047] Step 7: Device Assembly and Debugging. Connect the electrodes from each unit to the integrated power management circuit, and adjust the circuit parameters to ensure effective merging of pulse signals and DC signals; adjust the overall tilt angle of the device to 45° (to accommodate droplet impact and light reception), and conduct performance tests to ensure that the triboelectric output voltage is ≥500 V, the piezoelectric output voltage is ≥1 V, and the photovoltaic output voltage is ≥2 V, meeting the power supply requirements of subsequent electronic equipment.

[0048] The performance of the above-mentioned leaf-inspired three-source composite energy harvesting device was tested, and the performance test results are as follows: Figures 4-7 As shown.

[0049] Figure 4 The piezoelectric output of the leaf-inspired three-source composite energy harvesting device is approximately ±1.3 V, the triboelectric output is approximately 540 V, and the photoelectric output is approximately 2 V, under the conditions of a droplet diameter of 5.10 mm, a release height of 20 cm, an impact frequency of 6 Hz, a device placement angle of 45°, and an illumination intensity of 1 sun.

[0050] Figure 5 To investigate the effects of different device placement angles (15°, 45°, and 75°) on the electrical output behavior under fixed conditions of a droplet diameter of 5.10 mm, a release height of 20 cm, and an impact frequency of 6 Hz, the results show that the piezoelectric output monotonically increases with increasing angle (the normal impact component increases, improving deformation and conversion efficiency); the triboelectric output reaches its peak at 45° (optimal spreading range and contact time), and decreases as the angle deviates.

[0051] Figure 6 To maintain a constant device placement angle of 45°, droplet diameter of 5.10 mm, and impact frequency of 6 Hz, the effect of droplet release height (5 cm, 20 cm, and 35 cm) on the device's output performance was investigated. The piezoelectric output continuously increased with height (due to increased droplet kinetic energy, impact momentum, and deformation); the triboelectric output initially increased and then saturated, stabilizing after 20 cm as the droplet kinetic energy reached a critical threshold and contact charge accumulation reached dynamic equilibrium.

[0052] Figure 7 To further investigate the influence of droplet release frequencies (4 Hz, 6 Hz, and 8 Hz) on the device's output performance, the device was positioned at a fixed angle of 45°, with a droplet diameter of 5.10 mm and a release height of 20 cm. The piezoelectric output reached its peak at 6 Hz (resonating with the natural frequency of the cantilever beam, resulting in good phase matching and efficient energy conversion), and the output decreased at non-resonant frequencies. The triboelectric output was less affected by frequency and mainly depended on the contact state of a single droplet impact.

[0053] This invention provides a biomimetic composite energy harvesting device that can simultaneously collect the mechanical energy of droplet impact and solar energy, realizing the synergistic conversion of three mechanisms: triboelectric, piezoelectric and photovoltaic. The leaf-inspired three-source composite energy harvesting device is fabricated in an integrated manner using additive manufacturing technology and is suitable for scenarios requiring long-term independent power supply, such as IoT terminals, distributed sensor network nodes, and wearable electronic devices.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An additively manufactured leaf-inspired three-source composite energy harvesting device, characterized in that, It includes a leaf vein-inspired support substrate, a droplet triboelectric unit, a piezoelectric conversion unit, and a photovoltaic conversion unit. Each unit is integrated or spatially coupled to form an integrated structure that can collect droplet impact mechanical energy and solar energy synchronously or at different times and output electrical energy in a coordinated manner. The leaf vein-like support substrate is integrally formed using polymer material through 3D printing technology. The surface is provided with leaf vein-like liquid guiding stripes for guiding droplets, and it is also provided with a cantilever beam structure and photovoltaic unit fixing groove. The droplet triboelectric unit is integrated on the front side of the leaf vein-like support substrate. The droplet triboelectric unit includes a bottom electrode, a triboelectric dielectric layer and a top electrode from bottom to top. The piezoelectric conversion unit is integrated below the cantilever beam structure of the leaf vein-like support substrate and is used to convert the vibration of the substrate caused by droplet impact into electrical energy. The photovoltaic conversion unit is fixed in the hollowed-out photovoltaic unit fixing groove below the leaf vein-like support base, located below the leaf vein-like liquid guide stripes.

2. The additively manufactured leaf-like three-source composite energy harvesting device according to claim 1, characterized in that, The polymer material of the leaf vein-like support substrate is one of polycarbonate (PC), polylactic acid (PLA), or thermoplastic polyurethane elastomer (TPU). The 3D printing process adopts fused deposition modeling (FDM), with a printing temperature of 260℃-280℃, a printing speed of 200mm / s-280mm / s, and a layer thickness of 0.08mm-0.2mm.

3. The additively manufactured leaf-like three-source composite energy harvesting device according to claim 1, characterized in that, The bottom electrode of the droplet triboelectric unit is prepared by spraying conductive silver paint with a thickness of 80μm-120μm, a spraying angle of 45°, and a spraying distance of 15cm. The triboelectric dielectric layer is a polytetrafluoroethylene propylene (FEP) film with a thickness of 40μm-60μm, which is attached to the surface of the bottom electrode by a pre-tensioning process. The top electrode is attached to the surface of the FEP film with conductive aluminum tape with a width of 0.1mm-0.5mm.

4. The additively manufactured leaf-like three-source composite energy harvesting device according to claim 1, characterized in that, The piezoelectric conversion unit uses a PZT-5H piezoelectric sheet, which is attached to the fixed end surface of the cantilever beam with 3M quick-drying adhesive and leads out electrodes; the piezoelectric cantilever beam has a length of 5mm-9mm and a thickness of 0.5mm-0.9mm, and is adapted to droplet release frequencies of 4Hz-8Hz.

5. The additively manufactured leaf-like three-source composite energy harvesting device according to claim 1, characterized in that, The photovoltaic conversion unit uses a silicon-based solar panel, which is fixed to the base frame by bonding. After the positive and negative electrodes are led out, they are encapsulated and insulated with epoxy resin. The encapsulation curing temperature is 80℃ and the curing time is 2 hours.

6. The additively manufactured leaf-like three-source composite energy harvesting device according to claim 1, characterized in that, The overall tilt angle of the device is adjustable to optimize the droplet impact effect and the angle of sunlight incidence.

7. The additively manufactured leaf-like three-source composite energy harvesting device according to claim 1, characterized in that, The energy harvesting device also includes an integrated power management circuit, which combines, regulates, and stores the pulsed outputs of the droplet triboelectric unit and the piezoelectric conversion unit with the DC output of the photovoltaic conversion unit to achieve stable power output.

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