Bistable Energy Harvesting From Human Motion

2015 ◽  
Author(s):  
Wei Wang ◽  
Junyi Cao ◽  
Shengxi Zhou ◽  
Jing Lin
Keyword(s):  
Energy Harvesting ◽  
Human Motion ◽  
Ambient Vibration ◽  
Energy Output ◽  
Potential Well ◽  
Energy Devices ◽  
Energy Harvesters ◽  
Cantilever Structure ◽  
Well Function ◽  
Nonlinear Energy

Recently, the power supply for portable electronic devices using the electricity extracted from human motion and ambient vibrations has received considerable attention from multidiscipline field. Among many energy converting mechanisms, the ease miniaturization of piezoelectric cantilever structure propels many research groups to investigate the potential of efficient energy harvesting from ambient vibration using resonant phenomena. However, the incapability of traditional linear energy harvesting from low frequency or varying frequency vibrations has become an open issue. This paper investigates the feasibility of nonlinear energy harvesters with different bistable potential well functions in harvesting energy from walking and running vibration. The portable nonlinear energy harvesting device and its measurement system has been established to obtain the model parameter and excitation signal from human motion. The electromechanical model for bistable energy harvesters with different nonlinear restoring force is derived from theoretical method and experimental data. Numerical investigation under human walking and running vibrations shows that large amplitude interwell motion are easily achieved to improve energy output while the proper potential well function of bistable oscillators is designed. The comparative experiments for nonlinear energy devices with different potential well function are performed. The history and frequency spectrum of output voltage demonstrate the effectiveness of numerical simulation and the clear potential of bistable energy harvesting from human motion by means of appropriate potential function design.

Multimodal pizza-shaped piezoelectric vibration-based energy harvesters

2021 ◽  
pp. 1045389X2110069
Author(s):  
Virgilio J Caetano ◽  
Marcelo A Savi
Keyword(s):  
Energy Harvesting ◽  
Frequency Spectrum ◽  
Optimization Procedure ◽  
Single Mode ◽  
Ambient Vibration ◽  
Vibration Source ◽  
Element Analysis ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Harvesting Systems

Energy harvesting from ambient vibration through piezoelectric devices has received a lot of attention in recent years from both academia and industry. One of the main challenges is to develop devices capable of adapting to diverse sources of environmental excitation, being able to efficiently operate over a broadband frequency spectrum. This work proposes a novel multimodal design of a piezoelectric energy harvesting system to harness energy from a wideband ambient vibration source. Circular-shaped and pizza-shaped designs are employed as candidates for the device, comparing their performance with classical beam-shaped devices. Finite element analysis is employed to model system dynamics using ANSYS Workbench. An optimization procedure is applied to the system aiming to seek a configuration that can extract energy from a broader frequency spectrum and maximize its output power. A comparative analysis with conventional energy harvesting systems is performed. Numerical simulations are carried out to investigate the harvester performances under harmonic and random excitations. Results show that the proposed multimodal harvester has potential to harness energy from broadband ambient vibration sources presenting performance advantages in comparison to conventional single-mode energy harvesters.

Reliability-Based Design Optimization for Nonlinear Energy Harvesters

2015 ◽  
Author(s):  
Sumin Seong ◽  
Christopher Mullen ◽  
Soobum Lee
Keyword(s):  
Energy Harvesting ◽  
Design Optimization ◽  
Reliability Based Design Optimization ◽  
Vibration Energy Harvester ◽  
Reliability Design ◽  
Energy Harvesters ◽  
Reliability Based Design ◽  
Stable Characteristic ◽  
Tip Mass ◽  
Nonlinear Energy

This paper presents reliability-based design optimization (RBDO) and experimental validation of the purely mechanical nonlinear vibration energy harvester we recently proposed. A bi-stable characteristic was embodied with a pre-stressed curved cantilever substrate on which piezoelectric patches were laminated. The curved cantilever can be simply manufactured by clamping multiple beams with different lengths or by connecting two ends of the cantilever using a coil spring. When vibrating, the inertia of the tip mass activates the curved cantilever to cause snap-through buckling and makes the nature of vibration switch between two equilibrium positions. The reliability-based design optimization study for maximization of power density and broadband energy harvesting performance is performed. The benefit of the proposed design in terms of excellent reliability, design compactness, and ease of implementation is discussed. The prototype is fabricated based on the optimal design result and energy harvesting performance between the linear and nonlinear energy harvesters is compared. The excellent broadband characteristic of the purely mechanical harvester will be validated.

Design enhancement and non-dimensional analysis of magnetically-levitated nonlinear vibration energy harvesters

2017 ◽  
Vol 28 (19) ◽  
pp. 2810-2822 ◽  
Author(s):  
Abdullah Nammari ◽  
Hamzeh Bardaweel
Keyword(s):  
Energy Harvesting ◽  
Energy Harvester ◽  
Magnetic Levitation ◽  
Energy Harvesters ◽  
The Past ◽  
Magnetic Forces ◽  
Linear Version ◽  
Harvesting Techniques ◽  
Unique Potential ◽  
Nonlinear Energy

Over the past decade, there has been special interest in developing nonlinear energy harvesters capable of operating over a wideband frequency spectrum. Chief among the nonlinear energy harvesting techniques is magnetic levitation–based energy harvesting. Nonetheless, current nonlinear magnetic levitation–based energy harvesting approaches encapsulate design challenges. This work investigates some of the design issues and limitations faced by traditional magnetic levitation–based energy harvesters such as damping schemes and stiffness nonlinearities. Both experiment and model are used to quantify and evaluate damping regimes and stiffness nonlinearities present in magnetic levitation–based energy harvesters. Results show that dry friction, mostly ignored in magnetic levitation–based energy harvesting literature, contributes to the overall energy dissipation. Measured and modeled magnetic forces–displacement curves suggest that stiffness nonlinearities are weak over moderate distances. An enhanced design utilizing a combination of mechanical and magnetic springs is introduced to overcome some of these limitations. A non-dimensional model of the proposed design is developed and used to investigate the enhanced architecture. The unique potential energy profile suggests that the proposed nonlinear energy harvester outperforms the linear version by steepening the displacement response and shifting the resonance frequency, resulting in a larger bandwidth for which power can be harvested.

scholarly journals Performance enhancement of nonlinear asymmetric bistable energy harvesting from harmonic, random and human motion excitations

2019 ◽  
Author(s):  
Chris Bowen
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Lower Limb ◽  
Performance Enhancement ◽  
Basin Of Attraction ◽  
Harmonic Excitation ◽  
Human Motion ◽  
Experimental Investigations ◽  
Energy Harvesters ◽  
Negative Effect

Numerical and experimental investigations of nonlinear bistable energy harvesters (BEHs) with asymmetric potential functions are presented under various excitations for performance enhancement. Basin of attraction under harmonic excitation indicates that asymmetric potentials in BEHs have negative effect on the power output. Therefore, a proper bias angle is introduced to the asymmetric potential BEHs for performance enhancement. Numerical and experimental results show that the power output is actually improved in a certain bias angle range under harmonic and random excitations. Furthermore, experiments under human motion excitation demonstrate that the asymmetric potential BEHs could perfectly combine with the asymmetric motion of lower-limb to improve the performance.

Evaluation of Ring-Type Energy Harvesters

2011 ◽  
Author(s):  
S. D. Hu ◽  
H. Li ◽  
H. S. Tzou
Keyword(s):  
Energy Harvesting ◽  
Piezoelectric Layer ◽  
Piezoelectric Materials ◽  
Electrical Energy ◽  
Basic Structure ◽  
Open Circuit ◽  
Ambient Vibration ◽  
Practical Applications ◽  
Energy Harvesters ◽  
Segment Size

Piezoelectric materials can be used as electromechanical conversion mechanisms to transfer ambient vibration into electrical energy to power electronic devices. In this study, an elastic ring laminated with a piezoelectric layer on the inner surface is utilized as the basic structure for energy harvesting. The piezoelectric layer is uniformly segmented into several energy harvesting patches for practical applications. The generated electrical energy resulting from modal voltages is analyzed under the open-circuit condition. Two modal energy generations are evaluated: one is the energy induced by the membrane oscillation and the other is the energy induced by the bending oscillation. For practical design applications, energy generations are evaluated with respect to ring radius, piezoelectric layer thickness, ring thickness and segment size. The maximal energy of all harvester patches on the ring is calculated to determine the optimal patch locations with respect to various ring modes. By summing up energies generated from all harvesters on the ring, the overall energy is also evaluated Based on the normalizations and assumptions of parameters, results indicate that the larger the segment size is, the less the energy can be generated.

scholarly journals Analytical modelling of spiral cantilever structure for vibration energy harvesting applications

2018 ◽  
Vol 7 (2.21) ◽  
pp. 39
Author(s):  
Nevin Augustine ◽  
Hemanth Kotturu ◽  
S Meenatchi Sundaram ◽  
G S. Vijay
Keyword(s):  
Energy Harvesting ◽  
Piezoelectric Materials ◽  
Structure Design ◽  
Ambient Vibration ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Micro Scale ◽  
Cantilever Structure ◽  
Spiral Geometry ◽  
Tip Mass

Research on harvesting energy from natural resources is more focused as it can make microelectronic devices self-powered. MEMS based vibration energy harvesters are gaining its popularity in recent days to extract energy from vibrating objects and to use that energy to power the sensors. A solution for the major constrain for vibration energy harvesting in micro scale has been addressed in this paper. Cantilever beams coated with piezoelectric materials which are optimized to resonate at the source vibration frequency are used in most of the traditional vibration energy harvesting applications. In micro scale such structures have very high natural frequency compared to the ambient vibration frequencies due to which frequency matching is a constrain. Tip mass at the end of the cantilever reduces the resonant frequency to a great extent but adds to complexity and fabrication difficulties. Here, we propose a spiral geometry for micro harvester structures with low fundamental frequencies compared to traditional cantilevers. The spiral geometry is proposed, simulated and analyzed, to show that such a structure would be able to vibrate near resonance at micro scale. The analysis consists of Modal analysis, Mises stress analysis and displacement analysis in COMSOL Multiphysics. The result shows that the frequency has been reduced by a factor of 300 when compared to normal cantilever in the same volume. The work provides guideline for vibration energy harvesting structure design for an improved performance.  

A Novel Tri-Direction Energy Harvester Using Bimorph Cantilever Structure

2012 ◽  
Vol 220-223 ◽  
pp. 669-673
Author(s):  
Kang Qi Fan ◽  
Bo Wang ◽  
Hai Dong Huo
Keyword(s):  
Energy Harvesting ◽  
Theoretical Analysis ◽  
Resonance Frequency ◽  
Bluff Body ◽  
Energy Harvester ◽  
Maximum Output Power ◽  
Ambient Vibration ◽  
Maximum Output ◽  
Power Devices ◽  
Cantilever Structure

Energy harvesting for powering low-power devices has drawn considerable attention over the last decade. This paper reports a novel tri-direction energy harvester to scavenge energy from wind and vibration, or a combination of them. The proposed harvester consists of a triple-level bimorph cantilever with a mass block to harness energy from ambient vibration. The mass block also acts as an aerofoil and bluff body to scavenge energy from wind. Theoretical analysis shows that the maximum output power of the harvester is 2.77 W, and the resonance frequency is 79 Hz.

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