Prototype Of Energy Harvester Research Articles

An enhanced electromagnetic energy harvester based on dual ratchet structure with secondary energy recovery

Abstract With the continuous advancement of ultra-low-power electronic devices, capturing energy from the surrounding environment to power these smart devices has emerged as a new direction. However, most of the mechanical energy available for harvesting in the environment exhibits ultra-low frequencies. Therefore, the feasibility of self-powering low-power devices largely depends on the effective utilization of this ultra-low-frequency mechanical energy. Consequently, this work proposes an enhanced electromagnetic energy harvester based on a dual ratchet structure with secondary energy recovery. It converts ultra-low frequency vibrations into fast rotational movements by means of a rack and pinion mechanism, thus achieving high power output while maintaining a simple structure. Experimental tests demonstrate that the proposed harvester exhibits excellent power output under ultra-low-frequency external excitation. Under external excitation with a frequency of 1.5 Hz and an amplitude of 22 mm, with the optimal load matched at 20 Ω, the maximum power output reaches 598 mW, with a power density of 1572.65 μW/cm³. The secondary energy recovery power accounts for 34.4 %, resulting in a 52.56 % enhancement in the energy harvester's output performance. Additionally, hand-cranking tests indicate that the fabricated prototype of the electromagnetic energy harvester can power some common electronic devices, including smartphones, showcasing significant application potential.

(Digital Presentation) Mechanically Driven Electromagnetic Energy Harvesting for Power System Sensing Applications

Introduction Energy harvesting is a process of producing energy or usable power from the environment. Among potential ambient energy harvesting sources, electromagnetic (EM) field offers the great promise for emerging power system applications. This is because EM energies are widely available around the current-carrying wires (busbars) that connect various power devices and equipment. Most previous works on EM energy harvesting were built upon AC transmission lines [1-5], whereas modern power systems are typically driven by renewable DC energy sources. In this work, a mechanically-driven, DC-based EM energy harvesting system is designed and implemented as a lab-scale prototype to ultimately power sensing devices in the power system. Key Results: The schematic diagram and the photograph image of the EM induction experimental setup are shown in Figures 1a) and 1b), respectively. The energy harvester consists of a high permeability (μ ~ 2300) ferrite toroidal coil (cross sectional area 760 mm2) that is placed below a DC conducting (copper) slab at a distance of 1 cm. According to the Faraday’s law of induction (Equation 1), the open circuit voltage is proportional to the time rate of change of the magnetic flux (dφ/dt). This work is sharply distinguished from other works because the time variant nature originates from the physical vibration without using the AC power source. As seen in the figure, the toroidal coil is directly attached to a vibrator, thus experiencing a light-to-moderate amount of vibration. Here, the copper slab emulates the busbar in the power system, and the vibrator represents a practical scenario where the energy harvester is exposed to mechanical, machinery, and other noise sources.Figure 2 plots the open circuit voltage (VOC) as a function of the number of coil turns (N) for the experimental setup shown in Fig. 1. VOC was measured using a multimeter between two terminals of the coil for the maximum current of 3 A applied to the copper slab. As expected, a linear trend of VOC vs. N was observed with the VOC value as high as 51.4 mV for the case of 2,500 turns. Importantly, VOC is scalable to the value that is sufficiently high to drive most modern sensing devices because VOC is proportional to current (I). It is common that more than 100 A flows in the busbar of the power system, which escalates VOC to more than 1.7 V. The idea of increasing VOC by increasing current is confirmed in Figure 3; we repeated the experiments by lowering the current value in the copper slab, and obtained the linear trend line. Thus, both results shown in Figures 2 and 3 indicate a strong correlation of our energy harvester prototype with the EM theory. The maximum VOC value we obtained (51.4 mV) is separately shown in Figure 4 as a photograph image of the multimeter reading.In Table 1, we estimated the VOC values that can be readily achievable in the power system that affords the busbar current of 300 A and/or the 10,000 coil turns. For example, as compared with a previous work [3] with VOC of 1.4 V for 30 A (AC), this work features VOC of about 2 V with the 30 A DC power source. Significance: This work demonstrates the possibility of newly developing an mechano-electromagnetic energy harvester for modern power systems. Taking full advantage of EM energies and vibration present in the power system, the proposed DC-sourced energy harvesting scheme can greatly facilitate development and adoption of various sensing/monitoring/diagnosis device technologies. This is because these devices will not require separate batteries or power sources; they will be easily powered using the electromagnetic energy and mechanical vibration.

A hybrid energy harvesting approach for transmission lines based on triboelectric nanogenerator and micro thermoelectric generator

To effectively detect faults in transmission lines, monitoring the operating status of these lines is imperative. However, providing power to monitoring devices for transmission line status presents a significant challenge. In this research, a hybrid energy harvesting approach based on micro thermoelectric generator (MTEG) and triboelectric nanogenerator (TENG) is proposed, and a theoretical model for MTEG-TENG hybrid energy harvesting is established. This study develops an integrated energy harvesting prototype, which incorporates oscillating-TENG (O-TENGs), MTEGs, and a power management control unit. This prototype not only harvests energy from the vibrations of transmission lines but also converts the lines thermal energy into electricity. The Experiment results show that the maximum open-circuit voltages of O-TENG and MTEG reach 80.3 V and 1.094 V, respectively. Compared to a single MTEG energy harvesting device, the prototype of the MTEG-TENG hybrid energy harvesting device demonstrates a 5.36% improvement in energy harvesting and battery charging performance. Consequently, this approach achieves self-powered monitoring with excellent stability and lower manufacturing costs. It provides an efficient and durable power approach for transmission line status monitoring devices.

Experiment and performance analysis of serpentine-shaped cantilever beam for pipeline vibration-based piezoelectric energy harvester prototype development

Abstract Pipelines produce vibrations during fluid or gas transportation. These vibrations are less likely to cause structural failure as they exist with a small magnitude and can be harvested into useful energy. This paper presents a study on the piezoelectric energy-harvesting method converting mechanical energy from pipeline vibration into electrical energy. The performance of the serpentine-shaped piezoelectric cantilever beam was observed to check whether the design can produce the highest output voltage within the allowable vibration region of the pipeline from 10 to 300 Hz through finite element analysis using COMSOL Multiphysics software (Supplementary Material). In addition, this study investigates the energy-harvesting potential of the proposed design under real pipeline vibration conditions through a lab vibration test. The harvested energy output is evaluated based on various vibration frequencies and amplitudes, which gives an idea of the device and its performance under different operating conditions. The experiment result shows that the energy harvester produced an open-circuit voltage of 10.28–15.45 V with 1 g of vibration acceleration. The results of this research will contribute to the development of efficient piezoelectric energy harvesters adapted for pipeline environments.

Wearable All-Fabric Hybrid Energy Harvester to Simultaneously Harvest Radiofrequency and Triboelectric Energy.

Distributed micro-energy harvesting devices offer the flexibility, sustainability, and multi-scenario applicability that will be critical to wearable electronic products in the Internet of Things. The radiofrequency and triboelectric (RF-TE) hybrid energy harvester (HEH) concept and prototype is presented for the first time, to simultaneously capture the energy from ambient electromagnetic waves and biological motions. The proposed hybrid energy harvesting system consists of a wearable rectenna, a triboelectric nanogenerator (TENG), and a power management circuit (PMC). Among them, the all-fabric rectenna exhibits good impedance matching characteristics in the ISM frequency. The flexible TENG unit can generate a maximum power density of 0.024µWcm-2. The designed multifunctional fabric-based PMC can considerably enhance the controllability of harvested hybrid energy. Additionally, a normalizable fabric circuit board quasi surface mount technology (FCB-SMT) is proposed to integrate all modules on the same fabric substrate in one step, making the entire system superior mechanical robustness. The proposed wearable fabric-based RF-TE hybrid energy harvester is capable of successfully driving consumer electronics (such as sensors, watches, etc.). It provides a new energy solution strategy for self-powered wearable electronic devices and is anticipated to encourage the efficient utilization of renewable energy.

Magnetostrictive wires-epoxy resin composite structures for human motion energy harvesting

Encapsulation of magnetostrictive alloy wires in epoxy resin has great potential for energy harvesting and can be applied to energy harvesting in human motion. In this work, a magnetostrictive wire-epoxy resin arch composite structure was proposed for harvesting energy generated by foot motion. A prestress was introduced during the resin curing process, and the relationship between the output voltage and material properties was derived based on the Villari effect. Three kinds of Fe-based magnetostrictive wires were prepared and their magnetic properties were measured, then a prototype single-layer arch composite structure was fabricated and an experimental platform was built for testing, and the amplitude of the output open-circuit voltage could reach 936 mV under an impact pressure of 750 N, which proved that the Fe–Ga alloy composite structure was superior to Fe–Co and Fe–Ni alloys in energy harvesting. The double-layer arch-shaped Fe–Ga composite structures energy harvesting prototype outputs a maximum voltage of up to 940 mV in foot energy harvesting experiments, and collected a maximum power of up to 2.45 mW at a step frequency of 3.5 Hz. Consequently, this work emphasized the feasibility of magnetostrictive alloy-epoxy composite structures for energy harvesting in human motion and the potential for developing new ways of energy harvesting.

Lead-Free Piezoelectric Energy Harvester Based on 2D Bismuth Titanate.

The use of two-dimensional (2D) layered materials with a noncentrosymmetric structure dramatically increases the potential of nanoscale electromechanical systems and electronic devices. In this work, liquid-phase exfoliation of bulk bismuth titanate was employed to synthesize atomically thin 2D sheets and fabricate a high-performance piezoelectric energy harvester. The structural and morphological properties of the 2D sheets were analyzed, confirming their phase purity and layer formation. Piezoelectric properties of the 2D sheets were evaluated using Piezoresponse Force Microscopy (PFM), demonstrating a high d33 piezoelectric coefficient of 40 pm/V in a few-layer bismuth titanate nanosheet. A prototype energy harvesting device was fabricated with 2D bismuth titanate as the active material. The piezoelectric response of the fabricated device was recorded at different frequencies and forces, which yielded a maximum d33 of 57.8 pC/N at 1 Hz. Such a solid electromechanical performance at a relatively infinitesimal input response indicates that 2D bismuth titanate can be useful for piezoelectric energy harvesting applications.

A low-frequency vibration energy harvester employing self-biased magnetoelectric composite

Global energy shortage puts stringent demand for energy harvesters capable of transforming external green vibration sources into electrical power. Employing a self-biased magnetoelectric (ME) composite of FeCuNbSiB/Ni/PZT (lead zirconate titanate), a prototype of vibration energy harvester is designed and fabricated. The energy harvester has a circular orbit in which a permanent magnetic cylinder reciprocates once an initial kinetic energy is provided. Upon a vibration signal, like handshaking, movement of the permanent magnetic cylinder causes an alternative magnetic field, which was applied on the ME composite. Via magnetic-force-electrical coupling, the ME composite of FeCuNbSiB/Ni/PZT produces output voltage. Finite element simulation is carried out to reveal the underlying mechanism of the harvester. The analysis shows that a maximum output voltage of 7.63 V can be obtained once an original potential energy is applied for the magnet. In particular, the magnet moves back and forth automatically inside the circular orbit with no need to further apply the energy. The effectiveness of the energy output is experimentally verified. When handshaking the energy harvester, a maximum open-circuit voltage of 5.51 V can be generated. The study offers a solution for power supplying some miniaturized or portable devices, such as small hand set and pedometer.

Research on vibration energy harvesting technology of power equipment based on alternating magnet array

AbstractVibration with a frequency of 100 Hz is widely distributed in the power equipment, and it can provide a new way to supply energy for sensors by vibration energy harvesting. The vibration energy harvesting method based on electromagnetic induction principle was studied through the arrayed structure of magnets and coils. Static magnetic field models were established for four magnet array structures and it was found that the alternating magnet array has the largest magnetic flux and magnetic flux gradient. Based on the alternating magnet array, prototypes of energy harvester with vertical and parallel movement mode were proposed. Through structural parameter optimisation analysis, two different energy harvesters were fabricated and it was found that the energy harvester with a parallel movement mode has better output performances. The energy harvester could provide output voltage/current and power of 8.35 V/17.39 mA and 15.13 mW (matched resistance is 200 Ω) at an acceleration of 5 m·s−2. The 100 mF capacitor could be charged to 2.72 V within 300 s, and the final voltage of the capacitor is greater than 3 V, which could sustainably drive commercial wireless temperature/humidity sensors.

Enhanced thermoelectric performance of Bi2Te3 by carbon nanotubes and silicate aerogel co-doping toward ocean energy harvesting

In this work, we propose a doped-modified thermoelectric generator (TEG) film and apply it to an ocean energy harvesting prototype that primarily utilizes ocean thermal energy. Firstly, A new Bi2Te3-based thermoelectric material with improved performance was synthesized by doping Bi2Te3 with Carbon nanotubes (CNTs) for their high electrical conductivity and Silica aerogel for their low thermal conductivity. Subsequently, a performance-optimized, flexible thermoelectric film was fabricated using electron printing technology. By combining the flexible thermoelectric film with a Triboelectric nanogenerator (TENG) and Electromagnetic generator (EMG), a hybrid energy harvesting prototype was developed that can harvest marine renewable energy. The prototype demonstrates a relatively high output voltage of 61 V and an output power of 81.2 μW, corresponding to a power density of 8.1 W/m3 in simulated marine environmental experiments. This ocean-oriented hybrid energy prototype based on co-doped thermoelectric materials unveils new possibilities for self-powered devices in the field of ocean energy harvesting.

Development of a Photovoltaic-Based Module for Harvesting Solar Energy from Pavement: A Lab and Field Assessment

The concurrent worldwide energy crisis has become a strong incentive for researchers, governments, and industry professionals to focus on sustainable energy solutions. Consequently, pavement photovoltaic energy harvesting technologies, as one of the most common sustainable energy solutions, have recently seen a significant improvement, especially in the new innovative designs of pavement solar panels. In this study, an innovative design for a prototype energy harvesting system was proposed based on thin-film photovoltaic solar panels. In addition, the feasibility of utilizing the generated power of the proposed system to illuminate a pedestrian crosswalk to enhance the safety of an at-grade intersection was also analyzed. The designed prototype consists of a thin-film solar panel, a transparent cover to protect the solar panel, and a wooden frame to support the panel and distribute the load. Different materials for the transparent covering plates were investigated, including polycarbonate with varying thicknesses, textured GlassGrit, and textured float glass with corundum skid-resistant coating on the surface. Finite element analysis was also conducted to analyze the behavior of solar panel-incorporated layered asphalt pavement subjected to dynamic wheel loading. The results showed that the suggested model could sustain the structural loads of a moving wheel without failure. Experimental results of the study showed that considering the seven hours of operation on a typical sunny day, the proposed system could generate approximately 699 Watt-hour of power during 7 h of operation (9 a.m.–4 p.m.) from the 304.8 mm (12 inches) × 304.8 mm (12 inches) pavement solar panel.

Geometrically nonlinear model of piezoelectric wind energy harvesters based on vortex-induced vibration and galloping

The interaction between vortex-induced vibration (VIV) and galloping could enhance the performance of wind energy harvesters (WEHs). Though VIV-galloping interaction may cause large amplitude wind-induced vibrations, the effects of geometrical nonlinearity were not considered in the modeling of VIV-galloping interactive piezoelectric WEHs (PWEHs). In this work, based on the extended Hamilton’s principle, a geometrically nonlinear model (GNM) of cantilevered PWEHs with VIV-galloping interaction was derived. The model includes both the transverse and axial aerodynamic forces, and considers the effect of the rotation of the bluff body on the aerodynamic forces. The aerodynamic coefficients were extracted by a piecewise polynomial fitting in a relatively large range of angle of attack for the square cross-sectional bluff body. Two flexible PWEH prototypes were fabricated and tested in a small wind tunnel to verify the proposed model. After the mechanical damping ratio of the low-coupling piezoelectric energy harvester prototypes were identified based on purely electrical measurements, the steady-state root mean square voltages of the prototypes with increasing wind speed were worked out using geometrically linear model (GLM) and the proposed GNM, respectively, and then compared with experiments. Both models can accurately predict the VIV-galloping interaction, but GNM is much more accurate than GLM at a relatively high wind speed. The proposed GNM provides a powerful tool to develop VIV-galloping interactive PWEHs.

The Stability Analysis Of Floating Buoy As A Wave Energy Harvester For Malaysian Coastal Area

These days, the problems of the energy crisis and environmental pollution are rapidly getting worse. As a result, using renewable energy sources like solar, wind, and ocean energy serves as an alternative to the current conventional energy. The fastest-growing renewable energy source to produce electricity is ocean wave energy, which is also pollution-free. While ocean wave energy harvesting is not fully developed in Malaysia, there are some potential opportunities for it to be explored. There is a lack of stability in the wave energy harvester prototypes currently in use. Therefore, the aim of this study is to design a stable floating buoy as a wave energy harvester for the Malaysian coastal area and to conduct a stability analysis on the proposed design. In this study, the design of the floating buoy was based on the composition of previous studies done for power generation which is the NAHRIM’s Coastal Defense and Energy Generator (N-CODE). Commercial software was used as a medium to evaluate the stability performance of floating buoys in terms of hydrostatic and hydrodynamic analyses. The wave amplitude was regulated between 0.1 m and 1.0 m while the wave frequency was kept constant at 0.5 Hz. This floating buoy shows a significant result for stability in static conditions since its metacentric height is greater than the centre of gravity. Finally, it has been determined that the floating buoy concept is viable in the Peninsular Malaysian coastal region, where the floating buoy can endure 1.0 m of wave amplitude.

An Electromagnetic Wind Energy Harvester Based on Rotational Magnet Pole-Pairs for Autonomous IoT Applications

In this paper, we report a wind energy harvesting system for Internet of Things (IoT)-based environment monitoring (e.g., temperature and humidity, etc.) for potential agricultural applications. A wind-driven electromagnetic energy harvester using rotational magnet pole-pairs (rotor) with a back-iron shield was designed, analyzed, fabricated, and characterized. Our analysis (via finite element method magnetic simulations) shows that a back-iron shield enhances the magnetic flux density on the front side of a rotor where the series connected coils interact and convert the captured mechanical energy (wind energy) into electrical energy by means of electromagnetic induction. A prototype energy harvester was fabricated and tested under various wind speeds. A custom power management circuit was also designed, manufactured, and successfully implemented in real-time environmental monitoring. The experimental results show that the harvester can generate a maximum average power of 1.02 mW and maximum power efficiency of 73% (with power management circuit) while operated at 4.5 m/s wind speed. The system-level demonstration shows that this wind-driven energy harvesting system is capable of powering a commercial wireless sensor that transmits temperature and humidity data to a smartphone for more than 200 min after charging its battery for only 10 min. The experimental results indicate that the proposed wind-driven energy harvesting system can potentially be implemented in energetically autonomous IoT for smart agriculture applications.

Piezoelectric wave energy harvester

In this study, a new concept of a small-scale piezoelectric wave energy harvester operating on the acceleration-driven principle is proposed, designed, and tested. Six piezoelectric generators placed in the enclosure are used as energy conversion devices due to their high-frequency response and capability of withstanding relatively large strain. The advantages of the proposed device are that it can operate at deployment sites with consistent medium/small wave energy flux and can naturally float on the water surface. Since the proposed wave harvester is self-generating, adding an external source is unnecessary, which makes the harvester lightweight, cost-effective, and suitable for operation in remote rivers and lakes. Feasibility studies of the preliminary mechanical design were performed using numerical modeling complemented with laboratory and field experiments. The maximum generated power was calculated from the digital record of the measured voltage across the optimum load resistance. The final prototype of a single piezoelectric wave energy harvester could generate a maximum of 5 mW in the field experiments. A feasibility study of arrays of convertors was also investigated experimentally.

Describes the project of energy harvester prototype and the power conditioning circuit

Describes the project of energy harvester prototype and the power conditioning circuit

Design study of a nonlinear electromagnetic converter using magnetic spring

In this paper, an experimental and theoretical study for designing a nonlinear electromagnetic converter-based magnetic spring is performed. The governing equation of the converter is investigated. A special focus is given to the magnetic force acting on the moving magnet in dependence of its volume and the geometry of the two fixed magnets, i.e., disc or ring. For the developed analytical and numerical model, the same converter volume has been used for all conducted investigations. Several parameters have been studied that can be used to tune the nonlinearity behavior. Further, the coil axial position was investigated analytically and experimentally. An energy harvesting prototype consisting of an oscillating cylindrical magnet levitated between two stationary magnets is fabricated and evaluated through experiments. The open-circuit voltage obtained through the analytical model has been compared to the experiment and solutions to tune the harvester resonant frequency while maintaining its output power density were proposed.

Highly (00l)-textured BiFeO3 thick films integrated on stainless steel foils with an optimized piezoelectric performance

Piezoelectric BiFeO3 films were successfully prepared on 304 stainless steel (SS) foils via RF-magnetron sputtering at 450 °C. By adopting a LaNiO3/Pt/Ti tri-layer bottom electrode, a predominant (100)-orientation and a better crystalline morphology were achieved in the BiFeO3 film, resulting in better ferroelectric and dielectric properties targeted for piezoelectric applications than those directly grown on SS or LaNiO3/SS. These properties include a large remnant polarization (Pr~68 μC/cm2), a large coercive field (Ec~241 kV/cm) and a sizable self-bias (Ebi~ 158 kV/cm), as well as a low dielectric constant and a reduced dielectric loss (εr≤200 and tan δ ≤ 0.026 in 1 kHz-1 MHz). Based on this optimal BiFeO3-SS heterostructure, large converse and direct transverse piezoelectric coefficients |e31,f| ~ 1.7 C/m2 and 1.07 C/m2 were achieved in prototype piezoelectric actuator and energy harvester structures, respectively. These results suggest that BiFeO3-SS heterostructures have a great potential for applications in lead-free, metal-based piezoelectric micro-electro- mechanical systems (piezo-MEMS).

Low-Cost Sensors for Indoor PV Energy Harvesting Estimation Based on Machine Learning

With the number of communicating sensors linked to the Internet of Things (IoT) ecosystem increasing dramatically, well-designed indoor light energy harvesting solutions are needed. A first step in this direction would be to be able to accurately estimate the harvestable energy in a specific light environment. However, inside, this energy varies in spectral composition and intensity, depending on the emission source as well as the time of day. These challenging conditions mean that it has become necessary to obtain accurate information about these variations and determine their impact on energy recovery performance. In this context, this manuscript presented a method to apply an innovative energy harvesting estimation method to obtain practical and accurate insight for the design of energy harvesting systems in indoor environments. It used a very low-cost device to obtain spectral information and fed it to supervised machine learning classification methods to recognize light sources. From the recognized light source, a model developed for flexible GaAs solar cells was able to estimate the harvestable energy. To validate this method in real indoor conditions, the estimates were compared to the energy harvested by an energy harvesting prototype. The mean absolute error percentage between estimates and the experimental measurements was less than 5% after more than 2 weeks of observation. This demonstrated the potential of this low-cost estimation system to obtain reliable information to design energetically autonomous devices.

A low-frequency vibration energy harvester employing self-biased magnetoelectric composite

A prototype of vibration energy harvester is presented which mainly consists of a self-biased magnetoelectric (ME) composite, and a permanent magnetic cylinder which is connected to a spring (spring-magnet). The harvester shows its effectiveness in scavenging low frequency mechanical energies such as human motions. Upon a vibration signal with a displacement control of 3 cm and a frequency of 5 Hz, a peak-to-peak voltage of 2.65 V can be obtained. When hand shaking the prototype, a maximum peak-to-peak open circuit voltage of 2.52 V is induced. The output voltage is also tested when the prototype is worn on the waist, leg, and arm, under jumping, stepping or walking conditions. A maximum power of 14.44 μW is obtained for the prototype weighing 34.08 g at a vibration of 5 cm and 5 Hz across a 10 kΩ load. Finite element simulations are performed to reveal the vibration modes and the corresponding values of output voltage. Comparison between the experimental data and the calculation results helps to better understand the displacement of the harvester under the vibrations and its effects on the output voltage. The energy harvester holds promises for a powering miniaturized or portable devices.