Nonlinear Energy Harvester Research Articles

Optimized and robust orbit jump for nonlinear vibration energy harvesters

Optimized and robust orbit jump for nonlinear vibration energy harvesters

Nonlinear energy harvesting based alternate cooperative nonorthogonal multiple access with adaptive interference cancellation

We consider an energy-limited network, where a source node intends to communicate with two energy harvesting (EH) near-users and one far-user. We design a nonlinear EH-based alternate cooperative nonorthogonal multiple access (CNOMA) scheme, where the source node alternately superimposes the data of each near-user and the far-user and broadcasts the composite signal. When one near-user decodes the data of both the far-user and itself by using the adaptive interference cancellation technique, the other near-user can harvest energy from the received signal. The two near-users alternately and adaptively forward data to the far-user. We properly model the energy statuses of both the two near-users by defining a group of unequally-spaced discrete energy levels. We analyze the average success probability and throughput of each user, and use the differential evolution (DE) algorithm to efficiently achieve the maximum system throughput by jointly optimizing both the time and power allocation factors. We also present two benchmark EH-based transmission schemes for comparison. Extensive simulations are conducted to validate our theoretical analysis and reveal the impacts of various parameters.

Nonlinear dynamical behavior and energy harvesting analyses of flexoelectric MEMS under residual stresses: Application of machine learning for simulating the system

Over the last several decades, there has been a lot of research interest in the micro/nano-scale energy harvester, a technology that offers sustainable energy solutions for different micro/nano-electromechanical systems. Investigate various geometries, topologies, and material options for energy receiver designs, as well as interesting nonlinear responses that may be used to push the boundaries of energy receiver design, energy efficiency, and energy density. In the current work, the residual stresses in the system after fabrication, are modeled as the in-plane loading in the system. Although the majority of designs are restricted to MEMS alone, research shows that in-plane loading in the system greatly affects the non-linear vibration of the energy collector and illustrates the potential of increasing its performance by controlling the in-plane load. The impacts of in-plane loading in the MEMS at the microscale tissues were quantified by creating a stress-based piezoelectric-flexoelectric MEMS model and analyzing the non-linear frequency response using a time integrator and a Newtonian iterator. By contrasting them with the outcomes of mathematically modeling the current system and contrasting the outcomes of the current technique with the outcomes of the earlier study, the findings in a Python environment known as the XGBoost methodology are re-validated. This strategy is founded on the concept of “reinforcement,” which integrates many training methodologies with the detection of underperforming individuals to cultivate proficient learners. Finally, numerous suggestions for raising the nonlinear vibration of the energy harvester are carefully considered.

Reversible nonlinear energy harvester tuned by titling angle or clamping distance

This paper proposes a reversible nonlinear energy harvester to realize broadband vibration energy harvesting. Especially, the softening and hardening nonlinear responses of an M-shaped piezoelectric beam could occur by tuning the clamping distance or titling angle, which is unlike previous efforts to institute nonlinearity. The proposed M-shaped beam consists of a pre-bent steel beam, a piezoelectric patch, and a proof mass without magnetic components. According to the numerical and experimental results, the proposed harvester could achieve a broader operation bandwidth than its linear counterpart. Under the low forward sweep excitation level (3 m/s2), the proposed reversible nonlinear energy harvester can cover the wide low-frequency range of 13.4–27.6 Hz (or 18.1–28.8 Hz) by changing the clamping distance (or the tilting angle). Exploiting this tunable nonlinear phenomenon makes it more suitable to harvest energy from broadband vibration efficiently.

Performance of Full-Duplex Cooperative NOMA Network With Direct Link and Battery-Assisted Non-Linear Energy Harvesting Near User

Performance of Full-Duplex Cooperative NOMA Network With Direct Link and Battery-Assisted Non-Linear Energy Harvesting Near User

Revolutionizing Batteryless IoT Systems to Enhance Nonlinear Energy Harvesting Using RIS Active and Passive Elements

Revolutionizing Batteryless IoT Systems to Enhance Nonlinear Energy Harvesting Using RIS Active and Passive Elements

Joint Trajectory and Resource Optimization for UAV-Assisted SWIPT Systems: A Comparative Study of Linear and Nonlinear Energy Harvesting Models

Joint Trajectory and Resource Optimization for UAV-Assisted SWIPT Systems: A Comparative Study of Linear and Nonlinear Energy Harvesting Models

Numerical analysis and experimental validation of nonlinear broadband monostable and bistable energy harvesters

Vibration based piezoelectric energy harvesting has been receiving more and more attention for supplying usable electrical energy to low-power electronic devices. This type of energy can produce the desired voltage to power any low electronic device or wireless sensor. But most of them provide lower voltage and insufficient power. In this paper, the nonlinear magnetic field is introduced to broaden the effective resonant bandwidth for overcoming this issue. The dynamic linear and nonlinear model of magnetic coupling piezoelectric vibration energy harvester is established based on the Hamilton principle, Euler-Bernoulli beam theory, piezoelectric theory, and Kirchhoff's law and law of mechanics. Numerical solutions of nonlinear energy harvesting systems are studied by using the Runge-Kutta method. The bifurcation diagram, Poincare map, power spectrum, and phase trajectory of voltage output are investigated with different excitation amplitudes and frequencies. Simulation of linear and nonlinear model were illustrated at given excitation levels. Simulation results show the harvesting performance can be improved by proper external magnetic coupling and potential energy function. The theoretical harmonic balance analysis results verify the numerical solution and influence the mechanism of excitation levels and interface resistances. Experimental verification is carried out to measure the nonlinear restoring force and examine the performance of nonlinear bistable and monostable energy harvesters. The experiment results show the nonlinear bistable and monostable energy harvesters can provide larger voltage and more power.

Multi-Objective Optimization for IRS-Aidded Multi-user MIMO SWIPT Systems

In this paper, we investigate an intelligent reflecting surface (IRS) assisted simultaneous wireless information and power transfer (SWIPT) system in which users equipped with multiple antennas exploit power-splitting (PS) strategies for simultaneously information decoding (ID) and energy harvesting (EH). Different from the majority of previous studies which focused on single objective optimization problems (SOOPs) and assumed the linearity of EH models, in this paper, we aim at studying the multi-objective optimization problem (MOOP) of the sum rate (SR) and the totalharvested energy (HE) subject to the maximum transmit power (TP) constraint, the user quality of service (QoS), and HE requirements at each user with taking a practical non-linear EH (NLEH) model into consideration. To investigate insightful tradeoffs between the achievable SR and total HE, we adopt the modified weighted Tchebycheff method to transform the MOOP into a SOOP. However, solving the SOOPs and modified SOOP is mathematically difficult due to the non-convexity of the object functions and the constraints of the coupled variables of the base station (BS) transmit precoding matrices (TPMs), the user PS ratios (PSRs), and the IRS phase shift matrix (PSM). To address these challenges, an alternating optimization (AO) framework is used to decompose the formulated design problem into sub-problems. In addition, we apply the majorization-minimization (MM) approach to transform the sub-problems into convex optimization ones. Finally, numerical simulation results are conducted to verify the tradeoffs between the SR and the total amount of HE. The numerical results also indicate that the considered system using the IRS with optimal phase shifts provides considerable performance improvement in terms of the achievable SR and HE as compared to the counterparts without using the IRS or with the IRS of fixed phase shifts.

A novel M-shaped 2-DOF piezoelectric energy harvester with built-in outer-inner magnetic tri-stable oscillators for energy converting enhancement and applications

Tri-stable oscillators have been widely used to develop various nonlinear broadband energy harvesters. Focusing on further achieving high-performance piezoelectric energy harvester under broadband vibrations, a novel M-shaped 2-DOF piezoelectric energy harvester (M-PEH) with built-in outer-inner magnetic tri-stable oscillators is proposed, in which an inner magnetic tri-stable oscillator is built-in into a U-shaped outer magnetic tri-stable oscillator using its cut-out cantilever beam, assisted by the coupling interface to further enhance the dynamic responses. A complete physical model by considering the nonlinear coupling interaction between the outer-inner magnetic tri-stable oscillators is established to describe the dynamic performances under different system parameters. The theoretical model is well validated by experiments, which show that the proposed M-PEH has more compact size, wider operating frequency and higher power generation, offering an effective bandwidth of 20.1 Hz (5.1–25.2 Hz) at base excitation A = 5 m/s2, and achieving maximum output voltage 8.5 V and total peak power 26.7 μW. Compared to the original magnetic-coupling nonlinear tri-stable PEH, the effective bandwidth and total power have increased by 300 % and 662 % respectively, and the average power density is increased by 917 %. In addition, four main coupling interaction modes between the outer and inner built-in tri-stable oscillator are observed, in which the nonlinear synchronous coupling interaction is conducive to generating inter-well motion, leading to more mechanical energy being transferred from the outer tri-stable oscillator to the inner built-in tri-stable oscillator, thereby improving power generation capacity. Besides, the coupling interaction between these two tri-stable oscillators produces two close resonances which can be easily tuned to form a wide operating bandwidth. Practical applications prove that the proposed M-PEH has the ability to power low-powered electronic products, meeting the power supplying requirements of engineering community.

Investigation of nonlinear magnetic stiffness based thin-layer stacked piezoelectric generators with a force-amplification structure

This paper investigates a nonlinear piezoelectric stack energy harvester incorporating a magnetic spring (NPEH) that utilizes impact-induced frequency modulation to augment the harvested power. The proposed configuration comprises a force amplifier, a piezoelectric stack, a spring-mass system, and a limiter. We formulate a two-degree-of-freedom (2DoF) theoretical model that accounts for the nonlinear characteristics of the system and corroborate it with experimental data. We examine the effects of system parameters on the output performance of the NPEH and demonstrate that the nonlinear magnetic spring facilitates a wideband energy harvesting. For instance, when the surface magnetic field intensities of the upper and lower magnets are 156 mT and 256 mT, respectively, the operational bandwidth reaches 5.23 Hz, which is 154 % greater than that of a linear spring system. Additionally, the nonlinear magnetic spring mitigates the voltage decay during the collision period due to its hysteresis response, thereby increasing the average power. At an excitation frequency of 9 Hz and with surface field strengths of the upper and lower magnets set at 156 mT and 256 mT respectively, the NPEH generates an RMS power of 2.2 mW (with an instantaneous power peak of 1.20 W). We provide design guidelines for optimizing the energy harvesting performance based on the parametric analysis.

Periodic solutions and bifurcations of a tristable flutter-based energy harvester

This paper designs a tristable flutter-based energy harvester that can harvest large amplitude interwell wind-induced vibration energy. To explore its periodic responses and bifurcation characteristics, the harmonic balance method and the incremental harmonic balance method are employed to solve its approximate solutions by combining the two-point tracing algorithm. By analyzing the incremental harmonic balance solutions, three different response regions and five vibration types are found. The wind tunnel experiment verifies the existence of these vibration types and the correctness of incremental harmonic balance solutions. Five bifurcation points are analyzed using the Floquet theory, and two evolution paths of its periodic solutions are studied. Finally, the influences of the potential well depths on the stable periodic solutions are studied. The shallow potential energy well is beneficial to improving the response stability. This study aims to fill the gap in the semi-analytical and analytical solution of nonlinear flutter-based energy harvesters, contribute to the theoretical analysis of wind-induced vibration energy harvesting, and provide more possibilities for the design of high-performance wind-induced vibration energy harvesters.

Magnetic-linkage nonlinear piezoelectric energy harvester with time-varying potential wells: Theoretical and experimental investigations

Energy harvesting has emerged as a prospective solution for powering wireless sensors on the Internet of Things (IoT). However, the limited energy conversion efficiency remains a significant challenge, thereby hindering the feasibility of self-powered sensing in IoT. To address this issue, this paper proposes a magnetic-linkage nonlinear piezoelectric energy harvester (PEH) capable of effectively operating over a wide frequency bandwidth, particularly under low-level base excitations. The proposed PEH comprises one vertical and two horizontal piezoelectric beams, which are coupled by the magnetic force to realize the magnetic-linkage effect and create time-varying potential wells. A comprehensive theoretical model has been developed to reveal the working mechanisms of the magnetic-linkage effect and corresponding time-varying potential wells. Based on these foundations, theoretical results indicate that the magnetic configuration parameters have a significant impact on the magnetic-linkage effect and potential barriers. In addition, experimental investigations indicate that the magnetic-linkage effect broadens the effective frequency bandwidth, leading to a significant improvement in energy harvesting efficiency of up to 400% compared to the PEH without magnetic-linkage effect. Furthermore, the proposed PEH enables the realization of self-powered sensing in experiments. In summary, by exploiting the magnetic-linkage effect to create the time-varying potential wells, this innovative approach holds a great promising application for achieving high-efficiency energy harvesting from low-level environmental vibrations.

Combining orbit jump and potential wells optimizations for nonlinear vibration energy harvesters

Nonlinear vibration energy harvesters (VEHs) are widely used for scavenging vibrational energy due to their broadband behaviors. However, they exhibit multiple orbits of different powers for a given excitation, including low-power orbits that might limit their performance. To address this issue and enhance nonlinear VEHs performance, various studies have defined orbit jump strategies to transition from low-power to high-power orbits. Another way to maximize the power of nonlinear VEHs is to optimize their geometry by finely engineering their potential wells (PWs). In this letter, we propose an orbit jump strategy for bistable VEHs that combines the two latter approaches, i.e. that simultaneously optimizes their PWs while jumping from low-power to high-power orbits. This orbit jump strategy is optimized using a numerical criterion that takes into account the robustness of the jumps and the invested energy. The proposed orbit jump strategy has been experimentally validated for vibration frequencies between 30 and 60 Hz. It is shown that the proposed approach can increase the power by an average of 121 times over the considered frequency range. Compared to traditional orbit jump strategies, the proposed approach, which combines orbit jumping and PWs optimizations, increases by up to three times the harvested power.

Frequency Response for Sweep-Up and Sweep-Down of Piezoelectric Energy Harvester

PurposeThe aim of this work is to study the frequency response of linear and nonlinear piezoelectric vibration energy harvester (pVEH) based on Duffing-type nonlinearity and Kirchhoff’s law, and the effect of the effective electromechanical coupling on the frequency response of nonlinear pVEH.MethodsThe analytical technique based on the harmonic balance method (HBM) is used to obtain the mechanical and electrical frequency responses of linear and nonlinear pVEH, and the Jacobian matrix is used to analyze the solutions’ stability. The Runge–Kutta fourth-order method as a numerical technique is used to solve the ordinary differential equations of pVEH.ResultsThe analytical calculations are completed, and the frequency response solution of displacement of pVEH is contained in real and complex values and those of electrical responses are presented. The harmonic balance results are compared with numerical simulations for various hardening nonlinear springs. Simple analytical expressions for the jump points are suggested for the sweep-up and sweep-down frequencies of pVEH.ConclusionsThe analytical analysis shows that the jump-down frequency ratios have definite behaviors for each low and high effective electromechanical coupling of hardening-nonlinear pVEHs. Moreover, the jump-up frequency ratio is directly proportional to the effective electromechanical coupling of hardening nonlinear pVEHs.

Linear/Non-Linear Energy Harvesting Models via Multi-Antenna Relay Cooperation in V2V Communications

Vehicle-to-vehicle (V2V) communications is a part of next-generation wireless networks to create smart cities with the connectivity of intelligent transportation systems. Besides, green communications is considered in V2V communication systems for energy sustainability and carbon neutrality. In this scope, radio-frequency (RF) energy harvesting (EH) provides a battery-free energy source as a solution for the future of V2V communications. Herein, the employment of RF-EH in V2V communications is considered where the bit error probability (BEP) of a dual-hop decode-and-forward relaying system is obtained depending on the utilization of antennas at the relay. The multiple antenna power-constraint relay harvests its power by applying dedicated antenna (DA)/power splitting (PS) EH modes and linear (L)/nonlinear (NL) EH models. Moreover, the links between nodes are exposed to double-Rayleigh fading. Finally, the performance of different system parameters is compared using theoretical derivations of BEP. The results provide a comprehensive analysis of the proposed system considering PS/DA-EH modes and L/NL-EH models, as well as deterministic/uniformly distributed placement of nodes. It is observed that PS-EH outperforms DA-EH assuming a placement of an equal number of antennas and distances. Moreover, optimal performance of PS/DA-EH is achieved by allocating more power and increasing the number of antennas for EH, respectively.

Full-Duplex Cooperative Relaying with Non-Linear Energy Harvesting for Vehicular Communication

Full-Duplex Cooperative Relaying with Non-Linear Energy Harvesting for Vehicular Communication

Theoretical and experimental investigation on the advantages of auxetic nonlinear vortex-induced vibration energy harvesting

Due to its wide applicability, vortex-induced vibration (VIV) from wind and water flow has been explored for piezoelectric energy harvesting. However, the broadband VIV energy harvesting at low wind speeds is still a great challenge. In this paper, an auxetic nonlinear VIV energy harvester (ANVEH) is proposed. For the first time, the advantages of monostable softening behavior using magnetic attraction are investigated. It is found theoretically and experimentally that the monostable softening can broaden the working wind speed range whereas decreasing the peak energy output. Thus, the auxetic structure is proposed to compensate the decrease of peak energy output with the monostable softening due to its negative Poisson’s ratio and high stress distribution. Utilizing the experimentally validated theoretical model, parametric investigations are undertaken to examine the effects of various factors, including the magnetic separation distance, the stiffness and mass of the harvester, the dimension of the bluff body, the connected resistance, and the electromechanical coupling coefficient. Results show that no matter how the system parameters vary, the ANVEH has the superior performance than the plain nonlinear VIV energy harvester (PNVEH).

Asymptotic stability of a nonlinear energy harvester with mass disturbance undergoing Markovian jump

Stochastic mass has exerted a profound impact on the dynamics of the systems characterized by light mass and compact volume. This work delves into the asymptotic stability with probability one of a variable mass energy harvester. Firstly, the Gaussian white noise with Markovian jump is coupled to model the inherent randomness and discreteness of stochastic mass. Then, we have established an approximate dimensionless system based on an equivalent transformation. Using the stochastic averaging method, the averaged Itô stochastic differential equation of the amplitude within the approximated system is derived. With the linearization, we have deduced the largest Lyapunov exponent for the linearized equation. Furthermore, the necessary and sufficient condition for achieving asymptotic stability of the nonlinear energy harvester is proposed approximately by managing the largest Lyapunov exponent be negative. The study systematically dissects the effects of stochastic mass and Markovian jump on the asymptotic stability with probability one of a nonlinear energy harvester. Under the disturbance of stochastic mass, with the increase of linear stiffness, the stability of the system will change nonlinearly. Moreover, the stability regions of the nonlinear energy harvester under varying transition matrices and stochastic mass noise intensities are thoroughly given. The findings and conclusions presented in this paper have a certain theoretical significance for the management of the system stability in engineering practical.

Multiantenna Clustering Collaboration for WPCNs Based on Nonlinear EH

This article considers a wireless-powered communication network (WPCN) composed of a multiantenna hybrid access point (HAP) based on nonlinear energy harvesting (EH). To improve some distant WDs’ throughput performance, one of them is allowed to be selected as a cluster head (CH) to help transfer information from other cluster members (CMs). Nevertheless, the proposed clustering collaboration’s performance is essentially restricted by the CH’s energy-intensive consumption (EC), which requires to transfer every WDs’ information, covering its own. In order to figure out the question, the HAP’s energy beamforming (EB) capability with multiple antennas is utilized that can concentrate greater transmission power into the CH to equilibrate its EC to assist other WDs. To be specific, each WD’s throughput performance is firstly derived under the proposed approach. A high-efficiency optimization algorithm for addressing cooperative optimization problem is put forward. In addition, the simulations are carried out in the actual network environment, and the results demonstrate that our proposed clustering collaboration with multiple antennas can validly enhance the WPCN’s throughput fairness based on nonlinear EH.