Traditional Energy Harvesting Research Articles

Hybrid Triboelectric‐Electromagnetic‐Electric Field Energy Harvester for Simultaneous Wind and Electric Field Energy Capture in High‐Voltage Transmission System

AbstractWith the development of smart grids, efficient condition monitoring of high voltage transmission system has become crucial, necessitating reliable power supplies for distributed sensors. Traditional energy harvesters often focus on either internal or external sources, limiting overall efficiency. This study introduces a triboelectric‐electromagnetic‐electric field hybrid energy harvester (TEE‐HEH) that synergistically integrates triboelectric nanogenerators (TENGs), electromagnetic generators (EMGs), and electric field energy harvesters (EEHs) to simultaneously capture electric field and wind energy. Electric field energy is harvested via displacement currents between transmission lines and the ground, while TENGs and EMGs efficiently capture low‐ and high‐speed wind energy, respectively, enabling broadband harvesting (2.3–10 m s−1). The synergistic combination of TENG, EMG, and EEH within the TEE‐HEH leads to significantly enhanced energy capture efficiency from multiple sources. At a wind speed of 5 m s−1, a transmission line voltage of 25 kV, and a distance of 1.5 m, the TEE‐HEH achieved peak power outputs of 18.5 mW (TENG), 262 mW (EMG), and 1.85 mW (EEH), demonstrating enhanced energy collection efficiency. An environmental monitoring system has been powered, demonstrating the TEE‐HEH's practicality for dual‐source energy harvesting in smart grid applications.

MOF Derived Ni‐Cu Double Hydroxide Based Self‐Powered Flexible Asymmetric Supercapacitor Using Onion Scale as an Effective Bio‐Piezoelectric Separator

Modern electronic devices necessitate the utilization of compact, wearable, and flexible substrates capable of simultaneously harvesting and storing energy by merging traditional energy harvesting techniques with storage mechanisms into a singular portable device. Here, we present the fabrication of a low‐cost, sustainable, all‐solid‐state, self‐powered flexible asymmetric supercapacitor (SPASC) device. This device features MOF‐derived nickel‐copper double hydroxide nanosheets coated stainless steel (SS) fabric sheet (NCDH@SS) as the positive electrode, while manganese dioxide decorated activated porous carbon on SS fabric sheet (MnO2‐APC@SS) acts as the negative electrode. The electrodes are isolated by a PVA‐KOH gel electrolyte, while onion scale, a bio‐piezoelectric separator, ensures effective separation. The self‐charging ability of the device is demonstrated through mechanical deformation induced by finger imparting. This rectification‐free SPASC device exhibits remarkable performance, achieving a charge up to ~235.41 mV from the preliminary open circuit voltage of ~20.89 mV within 180 s under ~16.25 N of applied compressive force (charged up to ~214.52 mV). Furthermore, three SPASC devices connected in series can power up various portable electronic devices like wristwatches, calculators, and LEDs upon frequent imparting. Our work thus demonstrates an innovative and advanced approach towards the development of sustainable, flexible, and advanced self‐powered electronics.

Asymmetry stagger array structure ultra-wideband vibration harvester integrating magnetically coupled nonlinear effects

Traditional energy harvesters often have limitations in terms of bandwidth and power output, resulting in poor performance. This study reports a multi-strategy ultra-wideband energy harvesting device that utilizes an asymmetry, stagger array, magnetic coupling, and nonlinearity strategies to achieve high power output over an ultra-wideband frequency range without the need for external power input. The energy harvesting device consists of a base, two elastic beams, and two sets of asymmetric palm-shaped piezoelectric cantilever beam structures, each with a magnet attached at the tip. By reasonably arranging the palm-shaped mechanism and magnets, a magnetic coupling effect is introduced to achieve high power density output at non-resonant frequencies. Numerical analysis is conducted to evaluate the performance of the proposed structure, assess the influence of structural parameters, and establish a dynamic model to analyze the energy harvesting device. Experimental results demonstrate that the structure achieves a maximum power output of 60.49 mW at 19.9 Hz and 0.5 g, with a peak power density of approximately 8.065 × 103 W/m3. Within an ultra-wideband frequency range that spans 6 Hz to 64.2 Hz, the energy harvester maintains an output voltage which is more than 5 V. Furthermore, temperature and humidity monitoring are performed using Bluetooth sensors to adaptively assess the energy harvesting device, eliminating the need for lithium batteries and ensuring stable signal transmission. The device can be utilized for condition monitoring in any unstable vibration environment, contributing to the realization of distributed monitoring in the Internet of Things (IoT).

A composite energy harvester based on human reciprocating motion.

In this paper, a piezoelectric electromagnetic composite energy harvester is studied. The device consists of a mechanical spring, upper and lower base, magnet coil, etc. The upper and lower bases are connected by struts and mechanical springs and secured by end caps. The device moves up and down under the vibration of the external environment. As the upper base moves downward, the circular excitation magnet moves downward, and the piezoelectric magnet is deformed under a non-contact magnetic force. Traditional energy harvesters have the problems of a single form of power generation and inefficient energy collection. This paper proposes a piezoelectric electromagnetic composite energy harvester to improve energy efficiency. Through theoretical analysis, the power generation trends of rectangular, circular, and electric coils are obtained. Simulation analysis yields the maximum displacement of the rectangular and circular piezoelectric sheets. The device uses piezoelectric power generation and electromagnetic power generation to achieve compound power generation, improve the output voltage and output power, and can provide power supply to more electronic components. By introducing the nonlinear magnetic action, the mechanical collision and wear of the piezoelectric elements during the work are avoided, so that the service life and service life of the equipment is extended. The experimental results show that the highest output voltage of the device is 13.28V when the circular magnets mutually repel rectangular mass magnets and the tip magnet of the piezoelectric element is 0.6mm from the sleeve. The external resistance is 1000Ω, and the maximum power output of the device is 5.5 mW.

Performance investigation and parameter identification of inverse variable cross-section energy harvester

An important issue in traditional energy harvesters is that the best performance of the device is limited to the uneven longitudinal strain and electric displacement distributions. One solution to this challenge is to incorporate of variable cross-section design and rotational motion. In this study, we propose a new rotational inverse complex piezoelectric energy harvester featuring two beams for ultra-low-frequency rotation applications. A comprehensive electromechanical model is developed based on the extended Hamilton's principle, and the analytical models are extracted for vibration response and electric performance under ultra-low-frequency excitations. Closed-form analytical expressions of the rotational frequency, electrical load resistance, and centrifugal coefficient are derived to give in-depth insights into the influence mechanism of the centrifugal softening effect for the extreme conditions of RL→0 and RL→∞. Moreover, we propose a parameter identification method to recognize optimal electrical load resistance for ultra-low-frequency rotational scenarios in the absence case of experimental equipment. Based on the validated theoretical model, parametric studies are conducted to investigate the effects of the structural parameters on the dynamic behaviors and output electric performance, it can be concluded that the appropriation selection of the structural parameters can change the dynamic behaviors of the harvester and enhance the energy harvesting performance. Besides, the prototype of the proposed harvester was designed and fabricated and experiments were carried out. Both analytical simulation and experimental results show that the proposed inverse energy harvester has an excellent harvesting performance at the ultra-low-frequency rotational excitations, and the output voltage of the proposed inverse energy harvester is 12% larger than that of a traditional inverse energy harvester.

A bistable energy harvester with low base-acceleration and high root mean square output for train bogies: theoretical modeling and experimental validation

Energy harvesting provides potential power solutions for distributed sensors in rail transportation condition monitoring. However, reported harvesters have low efficiency and a narrow working bandwidth for rail transportation condition monitoring scenarios. An energy harvester is developed in this paper that has a higher energy output efficiency and a wider working bandwidth. The harvester is suitable for train monitoring scenarios. The key novelty lies in the combination of a spherical moving magnet and a cylindrical moving magnet to give a spherical–cylindrical coupled moving magnet, which not only maintains the advantage of low friction but also improves energy conversion efficiency. Furthermore, analytical models are established to describe the dynamics of the harvester with different moving magnets (spherical, cylindrical, spherical–cylindrical coupled), and a theoretical framework is established to guide the design. The theoretical model is validated by developed prototypes and experimental results. The working bandwidth of the energy harvester with a spherical–cylindrical coupled moving magnet is 9.5–45.1 Hz at 2g and the output power reaches 18.2 mW at 40 Hz and 1200 Ω load. Compared with traditional energy harvesters with cylindrical and spherical moving magnets, the base excitation is lower and the normalized output power is higher. Thus, this energy harvester is more suitable for train monitoring scenarios.

A high-performance mini-generator with average power of 2 W for human motion energy harvesting and wearable electronics applications

The sustainability of power supply for mobile electronic devices is a problem that needs to be solved urgently. The energy from human motion is an optimal solution for this problem. As for the traditional energy harvesters based on electromagnetic, triboelectric, and piezoelectric induction, energy management is the largest challenge because of the low conversion efficiency and output power. In this paper, a high-efficiency and high-power energy harvester (EPEH) is presented based on the intersecting beam array structure. It can effectively harvest the pressure energy of humans under the soles at the states of walking, running, and weight-bearing walking. The EPEH does not impair the flexibility of humans compared with joint energy harvesters. The intersecting beam array structure is key component, which can magnify the compression distance in the vertical direction of 3.4 times in the horizontal direction, facilitating maximum energy harvesting within a limited height. On the other hand, the design of rolling friction structure can effectively reduce energy loss and improve energy conversion efficiency. The result shows that the maximum average output power can reach 2 W at 7 km/h. Because of the high output power, the energy management circuits and voltage regulator circuits can be derived and stable work, the energy harvested by the EPEH can be stored in the lithium battery (3.7 V, 50 mAh). Furthermore, the generated energy could supply mobile phones, smart watches, light bulbs, flashlights, children's anti-lost devices, and so on. Through the energy management circuit and voltage regulator circuit (1.5 V and 5 V), the energy conversion efficiency of the device can reach 65.2 % at a compression velocity of 2500 mm/min and a frequency of 1.25 Hz. It is of great significance for the practical application of wearable energy harvesting technology and has multiple application prospects.

Reliability of the bi-stable piezoelectric energy harvester under random excitation

The bi-stable piezoelectric energy harvester can produce higher voltage and efficiency than traditional energy harvester. In this manuscript, the reliability of the bi-stable piezoelectric energy harvester excited by Gaussian white noise is investigated. The equivalent uncoupled equation of system is deduced on the basis of the generalized harmonic transformation for the bi-stable piezoelectric energy harvester original coupling system. The averaged stochastic differential equation for system energy of the equivalent uncoupled system is established using the stochastic averaging method. The conditional reliability function and the mean first-passage time are derived through the backward Kolmogorov equation and the generalized Pontryagin equation associated with the averaged stochastic differential equation. The influences of noise intensity, electromechanical coupling coefficient, and time constant ratio on the conditional reliability function and mean first-passage time are discussed. The analytical results are highly consistent with the numerical results that are obtained by the Monte Carlo numerical simulation.

Analysis of Double Elastic Steel Wind Driven Magneto-Electric Vibration Energy Harvesting System

This research proposes an energy harvesting system that collects the downward airflow from a helicopter or a multi-axis unmanned rotary-wing aircraft and uses this wind force to drive the magnet to rotate, generating repulsive force, which causes the double elastic steel system to slap each other and vibrate periodically in order to generate more electricity than the traditional energy harvesting system. The design concept of the vibration mechanism in this study is to allow the elastic steel carrying the magnet to slap another elastic steel carrying the piezoelectric patch to form a set of double elastic steel vibration energy harvesting (DES VEH) systems. The theoretical DES VEH mechanism of this research is composed of a pair of cantilever beams, with magnets attached to the free end of one beam, and PZT attached to the other beam. This study analyzes the single beam system first. The MOMS method is applied to analyze the frequency response of this nonlinear system theoretically, then combines the piezoelectric patch and the magneto-electric coupling device with this nonlinear elastic beam to analyze the benefits of the system’s converted electrical energy. In the theoretical study of the DES VEH system, the slapping force between the two elastic beams was considered as a concentrated load on each of the beams. Furthermore, both SES and DES VEH systems are studied and correlated. Finally, the experimental data and theoretical results are compared to verify the feasibility and correctness of the theory. It is proven that this DES VEH system can not only obtain the electric energy from the traditional SES VEH system but also obtain the extra electric energy of the steel vibration subjected to the slapping force, which generates optimal power to the greatest extent.

A low-frequency rotational electromagnetic energy harvester using a magnetic plucking mechanism

Energy harvesting from rotational motion, such as vehicle tires and rotational devices, remains a challenge because of the difficulty of balancing the harvesting frequency range and the power-generation density and efficiency. Traditional energy harvesters using the mechanism of magnetic plucking and piezoelectric conversion cannot overcome the inherent disadvantages of the output power and the strictness of the application conditions. In this study, a low-frequency rotational electromagnetic energy harvester using a nonlinear magnetic plucking configuration is proposed. Using the novel structure to pluck a cylindroid generating magnet in each rotational motion, the resetting effect provides a new way to stabilize the output voltage and improve the energy harvesting performance. Two design factors for controlling the resetting effect were studied theoretically and experimentally. The finite element method based on the Maxwell stress tensor not only helps in understanding the magnetic field density distribution in the energy harvesting process but also reveals the resetting mechanism. Simulating a vehicle tire with a diameter of 0.6 m rotating at a speed of approximately 20 km/h, it was experimentally validated that the maximum average output power across all the rotating frequencies (0.5–5.0 Hz) reached 13.13 mW under certain excitation conditions in the experiment, which is increased by 215.9% compared with the harvester without the resetting effect. The great performance under different application conditions demonstrated that the proposed electromagnetic energy harvester has a great potential in energy harvesting from low-frequency rotational motions.

Bi-Triggering Energy Harvesters: Is It Possible to Generate Energy in a Solar Panel under Any Conditions?

In this review, the concept of a hybrid solar cell system, called all-weather solar cells, a new view on energy harvesting device design, is introduced and described in detail. Additionally, some critical economical, technological, and ecological aspects are discussed. Due to drastic global climate changes, traditional energy harvesting devices relying only on solar energy are becoming less adaptive, hence the need for redesigning photovoltaic systems. In this work, alternative energy harvesting technologies, such as piezoelectric and triboelectric devices, and photoelectron storage, that can be used widely as supporting systems to traditional photovoltaic systems are analysed in detail, based on the available literature. Finally, some examples of all-weather solar cells composed of dye-sensitized solar cells (DSSC) and silicon solar cells, often modified with graphene oxide or phosphors materials, as new perspective trends in nanotechnology are presented. Two types of solar cell triggers are analysed: (i) solar cells working during day and night (DSSC with phosphors materials), and (ii) solar cells working under sun and rain conditions (piezoelectric and triboelectric silicon or DSSC solar cells).

Throughput Optimization of Parallel Sensing and Energy Harvesting Cognitive Radio Network

In cognitive radio, throughput of secondary user (SU) will depend on spectrum sensing performance and available power of secondary user to transmits data. As the secondary user dissipates energy for spectrum sensing operation and to maintain cooperation among multiple SUs can results in reduction of transmission power. To compensate this energy, an energy harvesting technique has introduced in cognitive radio by which SU can harvest energy from primary (PU) signal and this harvested energy will be utilized to transmit its data and increases the lifetime. In a traditional Energy Harvesting Cognitive Radio Network (EHCRN), SU can perform sensing and harvesting in separate slots which decrease the transmission time of secondary user results in reduction in throughput. To enhance the throughput of secondary user, a parallel operation of spectrum sensing and energy harvesting has been discussed. This parallel operation results in reduction of energy consumption and increases harvested energy that makes more energy to be available for transmission, which results in an increase of SU throughput. Simulation results using MATLAB shows that the proposed Parallel Sensing and Energy Harvesting CRN have improved the throughput compared to Traditional Energy Harvesting CRN and are analyzed with different parameters.

Stationary Response of Nonlinear Vibration Energy Harvesters by Path Integration

Abstract A path integration procedure based on Gauss–Legendre integration scheme is developed to analyze probabilistic solution of nonlinear vibration energy harvesters (VEHs) in this paper. First, traditional energy harvesters are briefly introduced, and their nondimensional governing and moment equations are given. These moment equations can be solved through the Runge–Kutta and Gaussian closure method. Then, the path integration method is extended to three-dimensional situation, solving the probability density function (PDF) of VEH. Three illustrative examples are considered to evaluate the effectiveness of this method. The effectiveness of nonlinearity of traditional monostable VEH is studied. The bistable VEH is further studied too. At the same time, equivalent linearization method (EQL) and Monte Carlo simulation (MCS) are employed. The results indicate that three-dimensional path integration method can give satisfactory results for the global PDF, especially when solving bistable VEH problems. The results of this method have better consistency with the simulation results than those of EQL. In addition, different degrees of hardening and softening behaviors of PDFs occur when the magnitude of nonlinearity coefficient increases or the bistable VEH is considered.

Vibration analysis and distributed piezoelectric energy harvester design for the L-shaped beam

The vibration characteristics of a cantilever L-shaped beam perpendicular to the horizontal plane are investigated in this paper. The dynamical model of the L-shaped multi-beam structure is established by using the Euler-Bernoulli beam theory, where vibration equations of each substructure, matching conditions of the connection and boundary conditions are included. Based on the modal orthogonality, the discrete dynamical model with finite degrees of freedom is obtained. Then the distributed piezoelectric energy harvester is proposed to collect the vibration energy of the L-shaped beam. Different the most traditional energy harvester that the piezoelectric material covers the surface of the structure, the distributed energy harvester is placed on the selected points. The genetic algorithm is adopted to obtain the optimal position that can provide the maximum output power. The validation and accuracy of the present model is verified by comparison with the finite element model. Numerical results show the discrete model can perform the dynamic characteristics of the structure well with only two modes. By the comparison of different configurations, it concludes that the optimal position of the distributed piezoelectric energy harvester is close to the fixed end of the whole cantilever structure.

Batteryless and Self-Reconfigurable Multimode RF Network using All-Passive Energy Smart-Sensing

In recent years, replacing the external control stimuli with internal control using characteristics of radio frequency (RF) signals (such as waveform or power level) has attracted considerable attention to the design of reconfigurable multifunctional RF devices. However, even with the most exciting techniques, the control process always needs a chip-based system to sense the power level or waveform of the incident RF signal, which is realised by additional supporting electronic components of the sensing and microcontroller circuits. Therefore, to achieve a batteryless structure, a majority of conventional works focus on using energy harvesters to convert energy from external environmental sources to DC energy for the electronic circuits. Herein, we propose a novel alternative approach to replace the traditional energy harvesters in batteryless RF devices with all-passive energy smart-sensing circuits. By exploiting the features of a nonlinear semiconductor device under different incident RF power values, the proposed network can passively self-sense the RF power level and dynamically self-control RF signal flow and power ratio. The operation of the proposed network can be considered as purely self-adaptation with control from the RF power level. Moreover, normal RF devices can be transformed to all-passive and batteryless purely self-reconfigurable devices via integration with the proposed structure. As proof of concept, the proposed network is integrated with a two-port antenna to experimentally demonstrate its purely self-reconfigurable polarisation. The proposed strategy is hereby expected to extend the field of batteryless self-reconfigurable multifunctional RF devices and pave promising new paths for the development of future intelligent, smart RF devices.

Centralized Q-Learning based Routing in EH-WSNs with Dual Alternative Batteries

Energy harvesting wireless sensor network (EH-WSN) uses a large number of sensor nodes to conduct environmental perception, data collection and data transmission through wireless links. However, the battery capacity of traditional energy harvesting wireless sensor is limited. In this paper, a kind of energy collection wireless sensor of dual-battery system is studied, and a centralized energy-aware routing algorithm based on reinforcement learning is proposed. Considering the energy of the overall link, each source node chooses a good path at the beginning of data transmission. After all the data is transmitted to the sink node, it selects the path according to the whole network state, and learns several times until it finds the best path choice. The simulation results show that the end-to-end delay of this protocol is lower than that of random packet forwarding.

GSMAC: Group-Scheduled MAC Protocol with Energy Beamforming in M2M Networks

In Machine-to-Machine (M2M) networks, an enormous number of stations with low energy budgets contend for the channel access in order to get the transmission opportunity, leading to huge amount of congestion. Energy beamforming technology enables wireless devices to replenish their energy much faster than the traditional energy harvesting strategies. In this paper, a group-scheduled Medium Access Control (GSMAC) protocol is proposed as a solution of managing the access of stations that transmit bursts of data packets while taking into account the benefit of energy beamforming technology in M2M networks. In the proposed protocol, nodes are grouped by multiple Power Beacons in order to reduce the high collision probability. Nodes first contend the channel access in each group for reservation opportunities so that the reserved nodes can transmit data and harvest energy simultaneously by Access Point scheduling the data and energy transfer order. Simulation and analytical results show that GSMAC has significant improvements compared with the traditional distributed coordination function in terms of saturation throughput, delay, and energy-related performances.

Resource Aware Hybrid Energy Harvesting for Wireless Sensor Networks

Sensors consume the resources to perform different operations, and energy of the nodes may be depleted due to excessive computational load; thus, may reduce the overall network lifespan as well as coverage area. Traditional energy harvesting schemes provides energy to the nodes in linear way but these schemes depend over a single source as well as these do not interact with the routing protocol. In this paper, a Hybrid Energy Harvester scheme for wireless sensor network is introduced which can utilize multiple energy sources for harvesting and also interact with the routing protocols to fulfill their energy requirements. Simulation based analysis using various protocols are performed under the QoS constraints.

Filtering antennas for energy harvesting in wearable systems

AbstractWearable systems are important for future smart home care for the disabled and ageing population. One of the key challenges is the power supply. One solution is to develop an energy harvesting system suitable for providing power wirelessly. The matching network and filter in traditional energy harvesting system occupy lots of space, introduce additional losses, and reduce the total efficiency. This paper presents a novel filtering antenna suitable for wearable energy harvesting systems. The developed antenna has a broadband operation, harmonics suppression, compact size, and low cost. Firstly, a novel technique for broadband filtering antenna modeling and design in order to realize complex input impedance is presented. By adjusting the external quality factors and coupling coefficients of the resonators, complex impedance matching can be realized. Then, the theory of characteristic mode is used for the modal analysis of the filtering antenna. To verify the design concept, a C‐band circularly polarized filtering antenna with complex impedance is designed and fabricated. The results show that the impedance bandwidth is more than 14.5% with a peak gain higher than 8.5 dBi. The proposed antenna is conjugate matched to the rectifying circuit at 5.8 GHz and mismatched at the second harmonic frequency to suppress the harmonic reradiation, leading to a compact rectenna structure.

Design and Implementation of A Batteryless Wireless Embedded System for IoT Applications

DOI: 10.26650/electrica.2018.28092 With the increasing popularity of embedded systems that consist of identifying, sensing, processing, and communication capabilities, the Internet of Things (IoT) has enabled many new application scenarios in diverse scientific fields and provided an important opportunity to build efficient industrial systems and applications. Most embedded systems consume power provided by fixed batteries with limited capacity. However, the main disadvantage of batteries is that they must be periodically replaced with new ones or recharged when they are depleted. This kind of maintenance process increases the cost and restricts the use in inaccessible places. Considering the limitations of battery power, alternative energy sources are required for interconnected devices to operate efficiently and effectively. Harvesting or scavenging energy from the environment is an important strategy to design self-powered systems employed in the IoT domain. Traditional energy harvesting applications use large energy storage devices to supply the power to the system whenever needed. Batteryless energy harvesting techniques have advantages to operate long periods of time without maintenance. In this study, we designed and implemented a supercapacitor-based, solar-powered wireless embedded system that can operate autonomously without the need of maintenance and battery replacement. Our goal is to explore and analyze the applicability and usefulness of batteryless wireless data communication and self-powered smart devices using energy harvesting technique in the IoT environment. In our experiments, we observed that our prototype boards operate well with low-power consumption without any performance degradation. Cite this article as : Yuksel ME. Design and Implementation of A Batteryless Wireless Embedded System for IoT Applications. Electrica, 2019; 19(1): 1-11.