scholarly journals Energy harvesting from human motions for wearable applications

2018 ◽  
Vol 69 (05) ◽  
pp. 390-393 ◽  
Author(s):  
WENYING CAO ◽  
WEIDONG YU ◽  
ZHAOLING LI
Keyword(s):  
Output Voltage ◽  
Mechanical Response ◽  
Mechanical Energy ◽  
Wearable Electronics ◽  
Peak Voltage ◽  
Low Frequencies ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
The Stability ◽  
Vertical Height

Harvesting biomechanical energy from human’s movement is an alternative solution to effectively power the wearable electronics. In this paper, two impact-driven piezoelectric energy harvesters were developed which can be integrated within human shoe-soles and also can be tailored to integrate in commercial carpets or outdoor roadway to harvest the massive mechanical energy from the passing vehicles or people crowds at low frequencies. For a comprehensive study, two buckling types of PVDF harvesters were selected and tested. It has been shown that the mechanical responses of the arch type prototype and the C type prototype are different. In addition, the mechanical response of the C type can be affected by the vertical height of the C type. The peak-peak voltage of the C type increases with the vertical height of the C type decreases. The peak-peak voltage of arch type is almost the same with the C type when the vertical height of which is 25 mm. The stability of the output voltage of the arch type is the worst when compared with that of the three C types. The stability of the output voltage of the C type when the vertical height of which is 25 mm is the worst among the three different vertical heights

Modeling and Performance Enhancement of Low-Frequency Energy Harvesters

2018 ◽  
pp. 826-862
Author(s):  
Abdessattar Abdelkefi
Keyword(s):  
Performance Enhancement ◽  
Mechanical Energy ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Ocean Waves ◽  
Sensors And Actuators ◽  
Low Frequencies ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
And Performance

There exist numerous low-frequency excitation sources, such as walking, breathing, and ocean waves, capable of providing viable amounts of mechanical energy to power many critical devices, including pacemakers, cell phones, MEMS devices, wireless sensors, and actuators. Harvesting significant energy levels from such sources can only be achieved through the design of devices capable of performing effective energy transfer mechanisms over low frequencies. In this chapter, two concepts of efficient low-frequency piezoelectric energy harvesters are presented, namely, variable-shaped piezoelectric energy harvesters and piezomagnetoelastic energy harvesters. Linear and nonlinear electromechanical models are developed and validated in this chapter. The results show that the quadratic shape can yield up to two times the energy harvested by a rectangular one. It is also demonstrated that depending on the available excitation frequency, an enhanced energy harvester can be tuned and optimized by changing the length of the piezoelectric material or by changing the distance between the two tip magnets.

Modeling and Performance Enhancement of Low-Frequency Energy Harvesters

2015 ◽  
pp. 159-196 ◽  
Author(s):  
Abdessattar Abdelkefi
Keyword(s):  
Performance Enhancement ◽  
Mechanical Energy ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Ocean Waves ◽  
Sensors And Actuators ◽  
Low Frequencies ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
And Performance

There exist numerous low-frequency excitation sources, such as walking, breathing, and ocean waves, capable of providing viable amounts of mechanical energy to power many critical devices, including pacemakers, cell phones, MEMS devices, wireless sensors, and actuators. Harvesting significant energy levels from such sources can only be achieved through the design of devices capable of performing effective energy transfer mechanisms over low frequencies. In this chapter, two concepts of efficient low-frequency piezoelectric energy harvesters are presented, namely, variable-shaped piezoelectric energy harvesters and piezomagnetoelastic energy harvesters. Linear and nonlinear electromechanical models are developed and validated in this chapter. The results show that the quadratic shape can yield up to two times the energy harvested by a rectangular one. It is also demonstrated that depending on the available excitation frequency, an enhanced energy harvester can be tuned and optimized by changing the length of the piezoelectric material or by changing the distance between the two tip magnets.

Optimization of spiral-shaped piezoelectric energy harvester using Taguchi method

2017 ◽  
Vol 24 (19) ◽  
pp. 4484-4491 ◽  
Author(s):  
R Tikani ◽  
L Torfenezhad ◽  
M Mousavi ◽  
S Ziaei-Rad
Keyword(s):  
Taguchi Method ◽  
Energy Harvester ◽  
Piezoelectric Materials ◽  
Mechanical Energy ◽  
Experimental Investigations ◽  
Optimum Level ◽  
Low Frequencies ◽  
Piezoelectric Energy ◽  
Resonance Frequencies ◽  
Design Values

Nowadays, environmental energy resources, especially mechanical vibrations, have attracted the attention of researchers to provide energy for low-power electronic circuits. A common method for environmental mechanical energy harvesting involves using piezoelectric materials. In this study, a spiral multimode piezoelectric energy harvester was designed and fabricated. To achieve wide bandwidth in low frequencies (below 15 Hz), the first three resonance frequencies of the beam were designed to be close to each other. To do this, the five lengths of the substrate layer were optimized by the Taguchi method, using an L27 orthogonal array. Each experiment of the Taguchi method was then simulated in ANSYS software. Next, the optimum level of each design variable was obtained. A test rig was then constructed based on the optimum design values and some experimental investigations were conducted. A good correlation was observed between measured and the finite element results.

scholarly journals On the Effects of Structural Coupling on Piezoelectric Energy Harvesting Systems Subject to Random Base Excitation

Aerospace ◽  
2020 ◽  
Vol 7 (7) ◽  
pp. 93
Author(s):  
Hamidreza Masoumi ◽  
Hamid Moeenfard ◽  
Hamed Haddad Khodaparast ◽  
Michael I. Friswell
Keyword(s):  
Energy Harvesting ◽  
Mechanical Response ◽  
Harmonic Excitation ◽  
Point Of View ◽  
Analytical Models ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Novel Approach ◽  
Band Limited ◽  
Multi Body

The current research investigates the novel approach of coupling separate energy harvesters in order to scavenge more power from a stochastic point of view. To this end, a multi-body system composed of two cantilever harvesters with two identical piezoelectric patches is considered. The beams are interconnected through a linear spring. Assuming a stochastic band limited white noise excitation of the base, the statistical properties of the mechanical response and those of the generated voltages are derived in closed form. Moreover, analytical models are derived for the expected value of the total harvested energy. In order to maximize the expected generated power, an optimization is performed to determine the optimum physical and geometrical characteristics of the system. It is observed that by properly tuning the harvester parameters, the energy harvesting performance of the structure is remarkably improved. Furthermore, using an optimized energy harvester model, this study shows that the coupling of the beams negatively affects the scavenged power, contrary to the effect previously demonstrated for harvesters under harmonic excitation. The qualitative and quantitative knowledge resulting from this analysis can be effectively employed for the realistic design and modelling of coupled multi-body structures under stochastic excitations.

scholarly journals The State-of-the-Art Brief Review on Piezoelectric Energy Harvesting from Flow-Induced Vibration

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hongjun Zhu ◽  
Tao Tang ◽  
Huohai Yang ◽  
Junlei Wang ◽  
Jinze Song ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Bluff Body ◽  
Mechanical Energy ◽  
Wake Flow ◽  
Structural Vibration ◽  
Small Scale ◽  
Flow Induced Vibration ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Self Powered

Flow-induced vibration (FIV) is concerned in a broad range of engineering applications due to its resultant fatigue damage to structures. Nevertheless, such fluid-structure coupling process continuously extracts the kinetic energy from ambient fluid flow, presenting the conversion potential from the mechanical energy to electricity. As the air and water flows are widely encountered in nature, piezoelectric energy harvesters show the advantages in small-scale utilization and self-powered instruments. This paper briefly reviewed the way of energy collection by piezoelectric energy harvesters and the various measures proposed in the literature, which enhance the structural vibration response and hence improve the energy harvesting efficiency. Methods such as irregularity and alteration of cross-section of bluff body, utilization of wake flow and interference, modification and rearrangement of cantilever beams, and introduction of magnetic force are discussed. Finally, some open questions and suggestions are proposed for the future investigation of such renewable energy harvesting mode.

scholarly journals Acoustic Energy Harvesting Through Multilayer Piezoelectric Harvester Model

2020 ◽  
Vol 9 (3) ◽  
pp. 1848-1856
Keyword(s):  
Energy Harvesting ◽  
Low Power ◽  
Mechanical Energy ◽  
Scaling Analysis ◽  
Ambient Vibrations ◽  
Specific Element ◽  
Power Sources ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Effective Transfer

Low-power requirements of contemporary sensing technology attract research on alternate power sources that can replace batteries. Energy harvesters’ function as power sources for sensors and other low-power devices by transducing the ambient energy into usable electrical form. Energy harvesters absorbing the ambient vibrations that have potential to deliver uninterrupted power to sensing nodes installed in remote and vibration rich environments motivate the research in vibrational energy harvesting. Piezoelectric bimorphs have been demonstrating a pre-eminence in converting the mechanical energy in ambient vibrations into electrical energy. Improving the performance of these harvesters is pivotal, as the energy in ambient vibrations is innately low. In this paper, we propose a mechanism namely MultilayerPEHM (Piezoelectric Energy Harvester Model) which helps in converting the waste or unused energy into the useful energy. Multilayer-PEHM contains the various layer, which is placed one over the other, each layer is placed with specific element according to their properties and size, the size of the layer plays an important part for achieving efficiency. Furthermore, this paper presents an audit of the energy available in a vibrating source and design for effective transfer of the energy to harvesters, secondly, design of vibration energy harvesters with a focus to enhance their performance, and lastly, identification of key performance metrics influencing conversion efficiencies and scaling analysis for these acoustic harvesters. Typical vibration levels in stationary installations such as surfaces of blowers and ducts, and in mobile platforms such as light and heavy transport vehicles, are determined by measuring the acceleration signal. The frequency content in the signal is determined from the Fast Fourier Transform.

scholarly journals Development and Validation of an Enhanced Coupled-Field Model for PZT Cantilever Bimorph Energy Harvester

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Long Zhang ◽  
Keith A. Williams ◽  
Zhengchao Xie
Keyword(s):  
Energy Harvester ◽  
Field Model ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Open Circuit ◽  
Conservation Of Energy ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Comparison Results ◽  
Coupled Field

The power source with the limited life span has motivated the development of the energy harvesters that can scavenge the ambient environment energy and convert it into the electrical energy. With the coupled field characteristics of structure to electricity, piezoelectric energy harvesters are under consideration as a means of converting the mechanical energy to the electrical energy, with the goal of realizing completely self-powered sensor systems. In this paper, two previous models in the literatures for predicting the open-circuit and close-circuit voltages of a piezoelectric cantilever bimorph (PCB) energy harvester are first described, that is, the mechanical equivalent spring mass-damper model and the electrical equivalent circuit model. Then, the development of an enhanced coupled field model for the PCB energy harvester based on another previous model in the literature using a conservation of energy method is presented. Further, the laboratory experiments are carried out to evaluate the enhanced coupled field model and the other two previous models in the literatures. The comparison results show that the enhanced coupled field model can better predict the open-circuit and close-circuit voltages of the PCB energy harvester with a proof mass bonded at the free end of the structure in order to increase the energy-harvesting level of the system.

A Distributed Parameter Electromechanical Model for Cantilevered Piezoelectric Energy Harvesters

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
A. Erturk ◽  
D. J. Inman
Keyword(s):  
Electromechanical Coupling ◽  
Mechanical Response ◽  
Exact Analytical Solution ◽  
Short Circuit ◽  
Open Circuit ◽  
Distributed Parameter ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Cantilevered Beams ◽  
Power Outputs

Cantilevered beams with piezoceramic layers have been frequently used as piezoelectric vibration energy harvesters in the past five years. The literature includes several single degree-of-freedom models, a few approximate distributed parameter models and even some incorrect approaches for predicting the electromechanical behavior of these harvesters. In this paper, we present the exact analytical solution of a cantilevered piezoelectric energy harvester with Euler–Bernoulli beam assumptions. The excitation of the harvester is assumed to be due to its base motion in the form of translation in the transverse direction with small rotation, and it is not restricted to be harmonic in time. The resulting expressions for the coupled mechanical response and the electrical outputs are then reduced for the particular case of harmonic behavior in time and closed-form exact expressions are obtained. Simple expressions for the coupled mechanical response, voltage, current, and power outputs are also presented for excitations around the modal frequencies. Finally, the model proposed is used in a parametric case study for a unimorph harvester, and important characteristics of the coupled distributed parameter system, such as short circuit and open circuit behaviors, are investigated in detail. Modal electromechanical coupling and dependence of the electrical outputs on the locations of the electrodes are also discussed with examples.

PZT Piezoelectric Energy Harvester Enhancement Using Slotted Aluminium Beam

2014 ◽  
Vol 1051 ◽  
pp. 932-936
Author(s):  
Mun Heng Lam ◽  
Hanim Salleh
Keyword(s):  
Energy Source ◽  
Renewable Energy Source ◽  
Lead Zirconate Titanate ◽  
Output Voltage ◽  
Energy Harvester ◽  
Lead Zirconate ◽  
External Beam ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Wide Range

This paper presents work on improving piezoelectric energy harvesters. Harvesting energy from vibrations has received massive attention due to it being a renewable energy source that has a wide range of applications. Over the years of development, there is always research to further improve and optimise piezoelectric energy harvesters. For this paper, the piezoelectric specimen is made of PZT (Lead Zirconate Titanate), brass reinforced and has 31.8mm length, 12.7mm width and 0.511mm thick. An external beam is implemented to provide deflection amplification which in turn increases the output of the energy harvester. Depending on the configuration of the external beam, it can amplify output voltage from 100% to 300%.

scholarly journals An E-shape broadband piezoelectric energy harvester induced by magnets

2018 ◽  
Vol 29 (11) ◽  
pp. 2477-2491 ◽  
Author(s):  
Qingqing Lu ◽  
Fabrizio Scarpa ◽  
Liwu Liu ◽  
Jinsong Leng ◽  
Yanju Liu
Keyword(s):  
Broad Spectrum ◽  
Output Voltage ◽  
Energy Harvester ◽  
Variation Principle ◽  
Frequency Bandwidth ◽  
Restoring Force ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Half Power ◽  
Tip Mass

We describe in this work a broadband magnetic E-shape piezoelectric energy harvester with wide frequency bandwidth. We develop first a nonlinear electromechanical model of the harvester based on the Hamilton variation principle that simulates the effect of the nonlinear magnetic restoring force at different spacing distances. The model is used to identify the distances existing between two different magnets that enable the system to perform with a specific nonlinearity. The performance of the E-shape piezoelectric energy harvester is also investigated through experiments, with E-shape energy harvesters at different spacing distances tested under several base acceleration excitations. We observe that the frequency domain output voltage of the system shows a general excellent controllable performance, with a widening of the frequency bandwidth. The half-power bandwidth of the linear energy harvester for a distance of 25 mm is 0.8 Hz only, which can be expanded to 2.67 Hz for the larger distance of 11 mm between magnets. The energy harvester presented in this work shows promising performances for broad-spectrum vibration excitations compared to conventional cantilever piezoelectric energy harvester systems with a tip mass.

Sign in / Sign up

Export Citation Format

Share Document