Energy Harvester Configuration Research Articles

Multifunctional Thermochromic Dye‐Integrated Hybrid Nanogenerators for Mechanical Energy Harvesting and Real‐Time IoT Sensing

AbstractHybrid nanogenerators are advanced mechanical energy harvesters capable of simultaneously scavenging multiple types of energy. Additionally, thermochromic materials provide a practical and visually assessable method for real‐time temperature monitoring. In this report, a novel energy harvester and sensing patch (EHSP) is introduced, that utilizes combined piezoelectric and triboelectric effects to harvest mechanical energy efficiently. To optimize the EHSP, various energy harvester configurations are fabricated and tested, and the dielectric properties of triboelectric films are systematically investigated. These improvements are implemented to augment the overall energy harvesting capability. The thermochromic properties of the EHSP are also explored to enhance both the electrical performance and thermal responsiveness. The EHSP demonstrates the ability to generate maximum voltage and current outputs of 350 V and 20.4 µA, respectively. Moreover, it can detect temperature changes within seconds, making it suitable for both energy harvesting and sensing applications. The EHSP is tested in practical scenarios, proving its efficiency as an energy harvester and sensor for everyday human activities. Furthermore, its integration with multiple hybrid nanogenerators showcases its potential for industrial and wearable sensing applications.

Design and analysis of triboelectric energy harvester with an application in self-powered smart mask

The epidemiological information concerning novel corona virus (SARS-Cov-2) seeks attention nowadays to get an overview of global as well as country-based cases and deaths so far. The utilization of face mask has become evident for the protective measure of mankind to filter out the infiltrating virus from outside. In this paper, we have analysed various triboelectric based energy harvester configurations focusing on its application in self-powered smart mask design to combat SARS-Cov-2. Smart mask will comprise of triboelectric nanogenerator (TENG) and a smart layer to execute electrocution of the infiltrating virus as well as ensure the safety of human being (I < 10 mA). The theoretical investigations and simulation studies are carried out for different triboelectric materials and a comparative analysis is also portrayed in the context of designing self-powered smart mask under different operating modes. It has been observed that polypropylene-poly methyl methacrylate (PP-PMMA) material combination produces an electrical field of 0.9916 MV/m which is sufficient to electrocute the virus without causing harm to human body. Hence the design and comprehensive analysis is carried out considering PP-PMMA combination for various possible modes of operation like constant velocity, constant acceleration, sinusoidal and generic one. Here, respiration is considered as major mechanical input source for TENG whereas other biomechanical activities like talking, chewing are also discussed in the context of self-powered application of smart mask. It has been demonstrated that the physiological activity like chewing and respiration altogether produce a typical input force of 23.65 N which is sufficient to electrocute the incoming virus without causing any hazard to human health.

Applications of Sustainable Hybrid Energy Harvesting: A Review

This paper provides a short review of sustainable hybrid energy harvesting and its applications. The potential usage of self-powered wireless sensor (WSN) systems has recently drawn a lot of attention to sustainable energy harvesting. The objective of this research is to determine the potential of hybrid energy harvesters to help single energy harvesters overcome their energy deficiency problems. The major findings of the study demonstrate how hybrid energy harvesting, which integrates various energy conversion technologies, may increase power outputs, and improve space utilization efficiency. Hybrid energy harvesting involves collecting energy from multiple sources and converting it into electrical energy using various transduction mechanisms. By properly integrating different energy conversion technologies, hybridization can significantly increase power outputs and improve space utilization efficiency. Here, we present a review of recent progress in hybrid energy-harvesting systems for sustainable green energy harvesting and their applications in different fields. This paper starts with an introduction to hybrid energy harvesting, showing different hybrid energy harvester configurations, i.e., the integration of piezoelectric and electromagnetic energy harvesters; the integration of piezoelectric and triboelectric energy harvesters; the integration of piezoelectric, triboelectric, and electromagnetic energy harvesters; and others. The output performance of common hybrid systems that are reported in the literature is also outlined in this review. Afterwards, various potential applications of hybrid energy harvesting are discussed, showing the practical attainability of the technology. Finally, this paper concludes by making recommendations for future research to overcome the difficulties in developing hybrid energy harvesters. The recommendations revolve around improving energy conversion efficiency, developing advanced integration techniques, and investigating new hybrid configurations. Overall, this study offers insightful information on sustainable hybrid energy harvesting together with quantitative information, numerical findings, and useful research recommendations that progress and promote the use of this technology.

The Electro-Mechanical Energy Harvesting Configurations in Different Modes from Machine to Self-Powered Wearable Electronics

The Electro-Mechanical Energy Harvesting Configurations in Different Modes from Machine to Self-Powered Wearable Electronics

Optimisation of Cantilever Based Energy Harvester Design for Railway Bridges

AbstractIn this paper, the authors investigate energy harvesting on railway bridges. A tuning process based on a statistical analysis of the mechanical energy generated by a lumped‐mass model is presented and validated. A cantilever‐based energy harvester configuration is applied, and the optimal design of 3D printed energy harvesters is studied. The electromechanical behaviour of the device is represented by an analytical model for the estimation of the energy harvested from train‐induced bridge vibrations. A genetic algorithm constrained to geometry and structural integrity is used to solve the optimisation problem. The design flexibility and energy performance are maximised by 3D printing of the substructure of the harvester. An optimal device prototype with PAHT CF15 substructure is designed and manufactured for a real bridge in the Madrid‐Sevilla High‐Speed line. The prototype is experimentally validated under laboratory conditions. Finally, the performance of energy harvesting is evaluated from in situ experimental data measured by the authors. The results allow quantifying the energy harvested in a time window of five hours and twenty‐seven train passages.

Design and analytical evaluation of an impact-based four-point bending configuration for piezoelectric energy harvesting

Aiming toward improved energy conversion in piezoelectric energy harvesters, this study investigates four-point bending (FPB) energy harvesters (FPB-EH) to explore their prominent features and characteristics. The FPB configuration innovatively extends energy harvesting capabilities relative to conventional cantilever beams. The FPB-EH comprises a composite piezoelectric beam that rests on two supports of a fixed clamp, excited by contact force applied at two contact lines on a moving clamp. A comprehensive analytical electromechanical model for the vibrating energy harvester is presented with unique modeling features, including multi-beam sections and multi-mode-shape functions. Solutions of the analytical model are presented for a wide range of contact force types, including steady-state solutions for harmonic forces, impact forces, periodic and non-periodic arbitrary forces. This comprehensive model progresses the state-of-the-art piezoelectric modeling knowledge and is readily applicable to various energy harvesting configurations. The model is validated against experimental results and finite element analysis. Next, a parametric study was performed to evaluate the effects of various FPB characteristics, including the fixed and moving clamp spans, the waveform, and the period-time of contact force. The results indicate that the FPB configuration can enhance energy conversion efficiency and normalized output energy by factors of over 3 and 6, respectively. Finally, guidance is given for selecting between cantilever and four-point bending configurations.

Analytical solutions of the energy harvesting potential from vehicle vertical vibration based on statistical energy conservation

Two kinds of approaches have been proposed to harvest the vibrational energy from a running vehicle, namely using a regenerative damper to replace a traditional hydraulic suspension damper, or adding one or more dynamic vibration absorbers (DVAs). Extensive studies have been conducted by simulation or experiment on the first approach, whereas the studies on the second approach are very limited and even the energy harvesting potential is not clear. This paper tries to present an analytical solution, to uniformly reveal the energy harvesting potential from vehicle vertical vibration by both approaches, with a focus on approaches with DVAs. A generic quarter car model is proposed to represent various vibration energy harvesting configurations. With a newly enunciated statistical energy conservation property for linear vibration systems, the analytical solution of the energy harvesting potential is derived for the proposed model subjected to random excitation. It is illustrated from these analytical expressions that the total vehicle vertical vibration energy is not directly related to DVA configurations, and the vibration energy dissipated in the tire can be transferred to the absorbers. Literature results and newly implemented statistical analyses are presented to validate and demonstrate the derived solutions. Sensitivity analysis is then performed to reveal the effect of various vehicle parameters on the energy harvesting potential.

An Experimental Study of the Aeroacoustic Properties of a Propeller in Energy Harvesting Configuration

The aim of the present manuscript is to investigate the noise footprint of an isolated propeller in different flight configurations for the propulsion of a hybrid-electric aircraft. Experimental tests were performed at the Low-Turbulence Tunnel located at Delft University of Technology with a powered propeller model and flush-mounted microphones in the tunnel floor. The propeller was investigated at different advance ratios in order to study the noise impact in propulsive and energy harvesting configurations. For brevity, this work only reports the results at the conditions of maximum efficiency in both propulsive and energy harvesting regimes, for a fixed blade pitch setting. Comparing these two configurations, a frequency-domain analysis reveals a significant modification in the nature of the noise source. In the propulsive configuration, most of the energy is related to the tonal noise component, as expected for an isolated propeller; however, in energy harvesting configuration, the broadband noise component increases significantly compared to the propulsive mode. A more detailed analysis requires separation of the two noise components and, for this purpose, an innovative decomposition strategy based on proper orthogonal decomposition (POD) has been defined. This novel technique shows promising results; both in the time and in the Fourier domains the two reconstructed components perfectly describe the original signal and no phase delays or other mathematical artifices are introduced. In this sense, it can represent a very powerful tool to identify noise sources and, at the same time, to define a proper control strategy aimed at noise mitigation.

Time-domain model and optimization for single-axis kinetic energy harvesters driven by arbitrary non-harmonic excitation

Energy harvesting is employed to extend the life of battery-powered devices, however, demanding applications such as wildlife tracking collars, the operating conditions impose size and weight constraints. They also only provide non-harmonic mechanical motion, which renders much of the existing literature inapplicable, which focuses on harvesting energy from harmonic mechanical sources. As a solution, we propose an energy harvesting architecture that consists of variable number of evenly-spaced magnets, forming a fixed assembly that is free to move through a series of evenly-spaced coils, and is supported by a magnetic spring. We present an electromechanical model for this architecture, and evolutionary optimization process that finds the model parameters which describe the time-domain behaviour observed in ground truth measurements. The resulting model can predict the time-domain behaviour of the energy harvester for any configuration of the proposed architecture and for any mechanical excitation. We also propose an optimization process that, using the electromechanical model, optimizes the energy harvester configuration to maximize the power delivered to a resistive load. The resulting optimized harvester design is specific to the particular kind of non-harmonic mechanical excitation to which it will be exposed. To demonstrate the effectiveness of our proposed model and optimization procedure, we constructed four energy harvesters, each with different configurations, and compared their measured behaviour with that predicted by the model, given an excitation that approximates footstep-like motion. We show that the model predictions were consistently within 25% of the RMS load voltage. We then synthesize an optimal energy harvester using the proposed optimization process. The resulting optimal design was constructed and tested using the same footstep-like excitation, and delivered an average power of 1.526 mW to a 30Ωload. This is a 2.8-fold improvement over an unoptimized reference design. We conclude that our proposed behavioural model and optimization process allows the determination of energy harvester designs that are optimized for a non-harmonic and specific input excitation.

Analysis of a Symmetrical Ferrofluid Sloshing Vibration Energy Harvester

Ferrofluid sloshing vibration energy harvesters use ferrofluid sloshing movement as a moving magnet between a fixed coil to induce current and, in turn, harvest energy from external excitations. A symmetric ferrofluid sloshing vibration energy harvester configuration is introduced in this study which utilizes four external, symmetrically placed, permanent magnets to magnetize a ferrofluid inside a tank. An external sinusoidal excitation of amplitude 1 m/s2 is imparted, and the whole system is studied numerically using a level-set method to track the sharp interface between ferrofluid and air. The system is studied for two significant length scales of 0.1 m and 0.05 m while varying the four external magnets’ polarity arrangements. All of the system configuration dimensions are parametrized with the length scale to keep the system configuration invariant with the length scale. Finally, a frequency sweep is performed, encompassing the structure’s first modal frequency and impedance matching to obtain the system’s energy harvesting characteristics.

A self-tunable wind energy harvester utilising a piezoelectric cantilever beam with bluff body under transverse galloping for field deployment

Natural vibrations can be harnessed using piezoelectric transducers and converted into electrical energy to power small electronic devices such as sensors network for structural health monitoring. One promising wind energy harvester configuration is a piezoelectric cantilever beam with a bluff body attached at the free end. The strain-induced into the cantilever by the galloping motion, and therefore the power produced is dependent on the bluff body shape, wind speed and the incidence angle of the wind to the bluff body face. Thus far, most studies related to piezoelectric cantilever beam with transverse galloping bluff body were conducted in wind tunnels with laminar flow and graduated wind speed increase. There is no research conducted on natural and chaotic wind conditions. The effectiveness of the bluff body in varying wind conditions is not known. In this study, a self-tunable piezoelectric wind energy harvester was proposed by using a rotating base to account for the erratic nature of wind in the field. Three bluff body prisms (square, triangle and D-section), fitted to a piezoelectric cantilever with fixed and rotating bases, were sequentially studied under the natural wind condition. Results indicated that the rotating base configurations have a higher cut-in speed when compared with the motionless base but was able to produce higher output power, especially with the use of a square prism as the bluff body under typical urban windspeed (i.e. 3–6 m/s). This first-ever field study demonstrated the potential and advantage of employing the piezoelectric wind energy harvester with a rotating base under natural and erratic wind conditions.

Experimental investigation of T-shaped piezoelectric energy harvester activating coupled transverse and shear mode

During the past decade, the researchers have explored some of the valuable energy sources that are wasted if these are not being utilized like heat and vibration. These energy sources can be converted into micro electric power which is required in numerous electronic applications like wireless sensors, actuators etc. Many of researchers have been working on extracting the energy from ambient vibration because of its free availability in ambient. In the present study, the T-shaped cantilever beam is presented for harvesting energy from vibration under shear mode using PZT-5H (Lead Zirconate Titnate) piezoelectric material. Experimental analysis is conducted to obtain open circuit voltage response over frequency for all the configurations of piezoelectric energy harvester under study. The experimental results presented in this study concludes that the open circuit voltage developed under shear mode is maximum (5.26 V) and significantly equal to the voltage corresponding to bending mode (5.41 V) for T-shaped piezoelectric cantilever energy harvester when proof mass of 100 g is placed only at one end. Output voltage developed under shear mode for the T-shaped cantilever configuration with 100 g proof mass on one end is observed higher by approximately 12.87%, 5.83% and 5.17% than voltage for T-shaped energy harvester configuration with 50-50 g, 70-30 g masses and 85-15 g proof masses respectively. It is interesting to note that the output voltage under bending mode is reduced approximately by 15% and increased approximately by 80.07% under twisting mode for T-shaped piezoelectric energy harvester with 100 g proof mass at one extreme end compared to the T-shaped piezoelectric energy harvester with 100 g proof mass at center.

The Novel CPW 2.4 GHz Antenna with Parallel Hybrid Electromagnetic Solar for IoT Energy Harvesting and Wireless Sensors

The design and implementation's novelty simultaneously utilizes the antenna's frequency, polarization, and feed structure to maximize the harvested RF energy and become a microstrip communication circuit for wireless sensor or communication systems in IoT devices. In addition, the optimization of the parallel circuit configuration has a voltage doubler model with an integrated parallel system and thin-film solar cells. Implementation of the antenna structure has two-line feeds in one antenna. Usage both feeds have the same function as CPW circular polarization. Another advantage is that there is no miss-configuration when installing the port exchanges when using both output ports simultaneously. The 2-port antenna has an area of 1/2 per port (where accessible wavelengths work well at the 2.4 GHz frequency). It has been shown to achieve a relatively narrow bandwidth of 86.5 percent covering WiFi frequency band networks and IoT communications. It does not require additional filters and analog matching circuits that cause power loss in the transmission process in parallel voltage doubler circuits. Integrating a reflector on the CPW antenna with two ports for placement of thin-film solar cells provides antenna gain of up to 8.2 dB. It provides a wide beam range with directional radiation. Using a multi-stage parallel to increase voltage output and integrated with a thin-film solar cell converter proves efficient in the 2.4 GHz frequency band. When the transmission power density is -16.15 dBm with a tolerance of 0.023, the novel energy harvester configuration circuit can produce an output voltage of 54 mV dc without adding solar cell energy. And Integrated thin-film solar cell a light beam of 300 lux in the radiation beam area of -16.15 dBm, the energy obtained has a value of 1,74467V. It also shows that the implementation of this configuration can produce an optimal dc output voltage in the actual indoor and outdoor ambient settings. The optimization of antenna implementation and the communication process with Multiple signal classifications improves the configuration of antennas that are close to each other and have identical phase outputs. It is instrumental and efficient when applied to IoT devices.

Characterization and Implementation of a Piezoelectric Energy Harvester Configuration: Analytical, Numerical and Experimental Approach

From the last few decades, the piezoelectric materials are playing a vital role in the field of energy harvesting because of their capability to convert mechanical energy from the surroundings into useful electrical energy. In this research, the performance of the piezoelectric energy harvester (PEH) in cantilever configuration with varying length and width of the patch as compared to the beam was analyzed. Moreover, the induced voltage and power harvested by the designed PEH are analyzed for the various configurations of piezoelectric patch (PZTp). The effect of length and width of the PZTp and beam is predicted for the energy harvesting phenomenon. The effect of different piezoelectric materials [i.e. Lead zirconate titanate (PZT-5A) and Barium titanate (BaTiO3)] bonded to different non-piezoelectric materials (i.e. Aluminum (Al) and fiberglass) is studied analytically. An analytical model is developed for three different cases to analyze the effect of varying patch length while keeping the length of the beam variable. Finite Element Models to study energy harvesting and modes of vibration for all three cases were developed. The results of the analytical model and numerical model are compared with experimental investigations and are found to agree with a maximum of 22% error. For the designed harvesters, the maximum power output is obtained for the test case in which PZT-5A patch of smaller length is bonded with Al patch of larger length. The analytical, numerical and experimental results depict a similar trend.

Energy Localization through Locally Resonant Materials.

Among the attractive properties of metamaterials, the capability of focusing and localizing waves has recently attracted research interest to establish novel energy harvester configurations. In the same frame, in this work, we develop and optimize a system for concentrating mechanical energy carried by elastic anti-plane waves. The system, resembling a Fabry-Pérot interferometer, has two barriers composed of Locally Resonant Materials (LRMs) and separated by a homogeneous internal cavity. The attenuation properties of the LRMs allow for the localization of waves propagating at particular frequencies. With proper assumptions on the specific ternary LRMs, the separation of scales (between the considered wave lengths and the characteristic dimension of the employed unit cells) enables the use of a two-scale asymptotic technique for computing the effective behavior of the employed LRMs. This leads to a complete analytic description of the motion of the system. Here we report the results achieved by optimizing the geometry of the system for obtaining a maximum focusing of the incoming mechanical energy. The analytic results are then validated through numerical simulations.

Theoretical modeling and nonlinear analysis of piezoelectric energy harvesters with different stoppers

This study focuses on investigating the dynamic mechanism and nonlinear analysis of a piezoelectric energy harvester with different stoppers so as to determine optimal impact energy harvesting configurations. Based on the Hamilton's principle, a set of coupled nonlinear governing equations for the energy harvesting system is established, which is then discretized by the Galerkin method. It is indicated that the energy harvester without stoppers displays a softening characteristic and this softening becomes more obvious with increasing the base acceleration. This is due to the considered geometric and inertia nonlinearities. By introducing stoppers to the harvester, however, the dynamic behavior changes from softening to hardening characteristic, owing to the induced impact force nonlinearity. Then four kinds of stoppers are compared and better stopper configurations for energy harvesting performance are picked out, following by the consideration of parametric analysis on stopper's stiffness, placed position and spacing distance. It is noted that there exists optimal parameter regions where the energy harvester can strike a balance between bandwidth and generated average power depending on excitation frequencies in surroundings.

Enhancement of vibration based energy harvesting using compound acoustic black holes

Abstract Acoustic black hole (ABH) effects can be obtained via proper structural tailoring to induce a gradual reduction of the flexural wave velocity, thus creating high energy density structural areas. The wave energy focalization effect shows promising features for establishing novel vibration energy harvester configurations in terms of the high energy level and broadband characteristics. In this study, an energy harvesting structure with ABH features which ensures the structural strength as well as enhances the harvesting performance is proposed and investigated. Considering the wavelength compression in ABHs, piezoelectric patches bonded on the surfaces of ABHs are sliced into micro arrays to convert the mechanical energy effectively, which make sure that the positive and negative electric charge generated on the surfaces of harvesters won’t be neutralized. Each of the transducers is shunted with a resistor impedance. Fully coupled numerical models which consist of vibrational structures and electrical circuits are built to assess the energy harvesting performance of ABH-feature beam and uniform beam under both steady state and transient excitations. Experiments are also conducted to verify the significant performance enhancement in the ABH beam as compared that in the uniform beam. It is shown that the ABH structural tailoring can be used for broadband vibration energy harvesting and boost the harvested power by more than one order of magnitude.

A Self-Powered Engine Health Monitoring System Based on L-Shaped Wideband Piezoelectric Energy Harvester.

Engine health monitoring is very important to maintain the life of engines, and the power supply to sensor nodes is a key issue that needs to be solved. The piezoelectric vibration energy harvester has attracted much attention due to its obvious advantages in configuration, electromechanical conversion efficiency, and output power. However, the narrow bandwidth has restricted its practical application. A self-powered engine health monitoring system was proposed in this paper, and an L-shaped wideband piezoelectric energy harvester was designed and implemented. The L-shaped beam-mass structure and the piezoelectric bimorph cantilever beam structure was combined to form the wideband piezoelectric energy harvester configuration, which realized effective output at both resonance points. The theoretical model and finite element simulation analysis of the wideband piezoelectric energy harvester were proposed and the parameters were optimized based on that to meet the requirement of the vibration frequency of the engine. The experimental results show that the proposed energy harvester can be applied into the automobile engine health monitoring system. Engine signal analysis results also demonstrate that the proposed system can be used for engine health monitoring.

Energy Harvesting Research: The Road from Single Source to Multisource.

Energy harvesting technology may be considered an ultimate solution to replace batteries and provide a long-term power supply for wireless sensor networks. Looking back into its research history, individual energy harvesters for the conversion of single energy sources into electricity are developed first, followed by hybrid counterparts designed for use with multiple energy sources. Very recently, the concept of a truly multisource energy harvester built from only a single piece of material as the energy conversion component is proposed. This review, from the aspect of materials and device configurations, explains in detail a wide scope to give an overview of energy harvesting research. It covers single-source devices including solar, thermal, kinetic and other types of energy harvesters, hybrid energy harvesting configurations for both single and multiple energy sources and single material, and multisource energy harvesters. It also includes the energy conversion principles of photovoltaic, electromagnetic, piezoelectric, triboelectric, electrostatic, electrostrictive, thermoelectric, pyroelectric, magnetostrictive, and dielectric devices. This is one of the most comprehensive reviews conducted to date, focusing on the entire energy harvesting research scene and providing a guide to seeking deeper and more specific research references and resources from every corner of the scientific community.

Static and dynamic analytical coupled field analysis of piezoelectric flexoelectric nanobeams: A strain gradient theory approach

Piezoelectric and flexoelectric nanostructures attracted great interest from different research communities for their potential applications as sensors, actuators and energy harvesters. Nevertheless, modeling and analysis of such structures are still under investigation. In fact, strain gradient effects are expected to be nonnegligible at the nanoscale level where they induce substantial variations on the static and dynamic responses of the nanostructure, especially when coupled field behavior are present. Therefore, flexoelectricity which refers to the electromechanical coupling between electrical polarization and mechanical strain gradient, is expected to be dominant at the nanoscale. In this paper, the main focus is to analyze analytically the static and dynamic responses of nanobeams, having different boundary conditions and electrical loads, where gradient elasticity, piezoelectricity and flexoelectricity are taken into account. We develop a complete mathematical model using Hamilton’s principle. The derived governing electromechanical coupled equations and corresponding boundary conditions are solved using a Galerkin procedure based on an assumed mode approach. The principal electromechanical outputs are calculated analytically for actuation and energy harvesting configurations. Bidirectional polarization, electric field and elastic strain gradient effect are taken into account in the developed model. Validation and comparison with previously published results showed that considerable decrease of the performance could be observed because of the introduction of the elastic strain gradient effect. The performance degradation is also more pronounced if the aspect ratio is reduced.