A Multiple-Degree-of-Freedom Velocity-Amplified Vibrational Energy Harvester: Part A — Experimental Analysis

2014 ◽  
Author(s):  
Declan O’Donoghue ◽  
Valeria Nico ◽  
Ronan Frizzell ◽  
Gerard Kelly ◽  
Jeff Punch
Keyword(s):  
Gaussian Noise ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Laser Doppler Vibrometer ◽  
Degree Of Freedom ◽  
Maximum Power ◽  
Resistive Load ◽  
Energy Harvesters ◽  
Transduction Mechanisms ◽  
Sinusoidal Excitation

Vibrational energy harvesters (VEHs) are devices which convert ambient vibrational energy into electrical power, offering an alternative to batteries for powering wireless sensors. Detailed experimental characterisation of a 2-degree-of-freedom (2-Dof) VEH is presented in Part A of this paper, while a theoretical analysis is completed in Part B. This design employs velocity amplification to enhance the power harvested from ambient vibrations, while also seeking to increase the bandwidth over which power can be harvested. Velocity amplification is achieved through sequential collisions between free-moving masses. Electromagnetic induction was chosen as the transduction mechanism as it can be readily implemented in a velocity amplified system, although other transduction mechanisms can also be used. The VEH prototype was tested experimentally under both sinusoidal excitation and exponentially correlated Gaussian noise, with different VEH geometries. The maximum power generated under a sinusoidal excitation of arms = 0.6 g was 12.95 mW for a resistive load of 13.5 Ω at 12 Hz, while the maximum power under exponentially correlated Gaussian noise with σ = 0.8 grms, autocorrelation time τ = 0.01s and resistive load 13.5 Ω was 5.3 mW. Maximum bandwidths of 54% and 66%, relative to the central frequency, were achieved under sinusoidal and noise excitation, respectively. The device shows resonant peaks at approximately 15 and 30 Hz, while significant power is also generated in the 17–20 Hz range due to non-linear effects. The VEH component dynamics were analysed using a laser Doppler vibrometer (LDV), while Lab VIEW was used to control the electromagnetic shaker, read the LDV signal and record the VEH output voltage. The aim of this investigation is to achieve a more complete understanding of the dynamics of velocity-amplified systems to aid the optimization of velocity amplified VEH designs.

scholarly journals Low-Cost Piezoelectric Sensor Characterization for Energy Harvesting Applications

Proceedings ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 25
Author(s):  
Paulo Afonso Ferreira Junior ◽  
Fernando de Souza Campos ◽  
Bruno Albuquerque de Castro ◽  
José Alfredo Covolan Ulson ◽  
Fabrício Guimarães Baptista ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Low Cost ◽  
Electrical Power ◽  
Electric Energy ◽  
Piezoelectric Sensor ◽  
Energy Conversion Efficiency ◽  
Piezoelectric Transducers ◽  
Maximum Power ◽  
Sensor Nodes ◽  
Resistive Load

Energy harvesting engineering fields constitutes a promising area to provide electrical power for low-power electric applications obtained from other sources of energy available in the environment such as thermal, electromagnetic, vibrational and acoustic by using transducers. Vibrational sources stand out as a main alternative to be used for generating electric power in sensor nodes in microelectronic devices due to the greater energy conversion efficiency and the use of a simple structure. The cantilever is the main system implemented in studies of obtaining electric energy from vibrations using piezoelectric transducers. Most of piezoelectric transducers in the literature are not yet commercially available and/or are difficult to access for purchase and use. This paper proposes the characterization of low-cost piezoelectric transducers, configured as sensors, for Energy Harvesting applications using three different sizes of circular piezoelectric transducers (PZTs.) with diameters of 3.4 cm, 2.6 cm and 1.5 cm. For all three different PZTs, it was found that the maximum power transfer occurs for a resistive load of 82 kΏ. The maximum power generated in the load for the three PZTs was 40 uW, 14 uW and 1.4 W; with RMS voltages of 2.8 V, 2.10 V and 0.6 V; an acceleration of 1.3 g and a vibration frequency approximate of 7 Hz.

Concurrent vibration attenuation and low-power electricity generation in a locally resonant metastructure

2022 ◽  
pp. 1045389X2110725
Author(s):  
Mohid Muneeb Khattak ◽  
Christopher Sugino ◽  
Alper Erturk
Keyword(s):  
Vibrational Energy ◽  
Laser Doppler Vibrometer ◽  
Total Power ◽  
Main Beam ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Vibration Attenuation ◽  
Electrodynamic Shaker ◽  
Electrical Loads ◽  
Power Outputs

We investigate piezoelectric energy harvesting on a locally resonant metamaterial beam for concurrent power generation and bandgap formation. The mechanical resonators (small beam attachments on the main beam structure) have piezoelectric elements which are connected to electrical loads to quantify their electrical output in the locally resonant bandgap neighborhood. Electromechanical model simulations are followed by detailed experiments on a beam setup with nine resonators. The main beam is excited by an electrodynamic shaker from its base over the frequency range of0–150 Hz and the motion at the tip is measured using a laser Doppler vibrometer to extract its transmissibility frequency response. The formation of a locally resonant bandgap is confirmed and a resistor sweep is performed for the energy harvesters to capture the optimal power conditions. Individual power outputs of the harvester resonators are compared in terms of their percentage contribution to the total power output. Numerical and experimental analysis shows that, inside the locally resonant bandgap, most of the vibrational energy (and hence harvested energy) is localized near the excited base of the beam, and the majority of the total harvested power is extracted by the first few resonators.

Design of a Compliant Flexure Joint for Use in a Flow Energy Harvester

2014 ◽  
Author(s):  
Punnag Chatterjee ◽  
Matthew Bryant
Keyword(s):  
Energy Harvester ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Flow Induced Vibration ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Flow Energy ◽  
Flexure Mechanism ◽  
Multiple Components ◽  
Compact Design

This paper presents an initial experimental and computational investigation of a flow-induced vibration energy harvester with a compliant flexure mechanism. This energy harvester utilizes the aeroelastic flutter phenomenon to convert the flow energy to vibrational energy which can be converted into useful electrical power using piezoelectric transducers. However, unlike previous flutter-based flow energy harvesters [1] which require assembling multiple components to create the necessary aeroelastic arrangement, the device described here utilizes a monolithic, compact design to achieve the same. In this paper, we propose a flexure design for this device and model it using analytic methods and finite element simulations. A proof of concept energy harvester incorporating this flexure design has been fabricated and experimentally investigated in wind tunnel testing.

scholarly journals A C-Battery Scale Energy Harvester: Part A — System Dynamics

2015 ◽  
Author(s):  
Valeria Nico ◽  
Elisabetta Boco ◽  
Ronan Frizzell ◽  
Jeff Punch
Keyword(s):  
System Dynamics ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Maximum Output Power ◽  
Average Power ◽  
Electrical Energy ◽  
Load Resistance ◽  
Maximum Output ◽  
Resistive Load ◽  
Sinusoidal Excitation

In recent years, the development of small and low power electronics has led to the deployment of Wireless Sensor Networks (WSNs) that are largely used in military and civil applications. Vibrational energy harvesting can be used to power these sensors in order to obviate the costs of battery replacement. Vibrational energy harvesters (VEHs) are devices that convert the kinetic energy present in the ambient into electrical energy using three principal transduction mechanisms: piezoelectric, electromagnetic or electrostatic. The investigation presented in this paper specifically aims to realize a device that converts vibrations from different ambient sources to electrical energy for powering autonomous wireless sensors. A “C-battery” scale (25.5 mm diameter by 57.45 mm long, 29.340 cm3) two Degree-of-Freedom (2-DoF) nonlinear electromagnetic energy harvester, which employs velocity amplification, is presented in this paper. Velocity amplification is achieved through sequential collisions between two free-moving masses, a primary (larger) and a secondary (smaller) mass. The nonlinearities are due to the use of multiple masses and the use of magnetic springs between the primary mass and the housing, and between the primary and secondary masses. Part A of this paper presents a detailed experimental characterization of the system dynamics, while Part B describes the design and verification of the magnet/coil interaction for optimum prototype power output. The harvester is characterized experimentally under sinusoidal excitation for different geometrical configurations and also under the excitation of an air-compressor. The maximum output power generated under sinusoidal excitation of arms = 0.4 g is 1.74 mW across a resistive load of 9975 Ω, while the output rms voltage is 4.2 V. Under the excitation of the compressor, the maximum peak power across a load resistance of 8660 Ω is 1.37 mW, while the average power is 85.5 μW.

scholarly journals Vibration Energy Harvester Based on Torsionally Oscillating Magnet

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1545
Author(s):  
Xinyi Wang ◽  
Jiaxing Li ◽  
Chenyuan Zhou ◽  
Kai Tao ◽  
Dayong Qiao ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Proof Mass ◽  
Vibrational Energy ◽  
Open Circuit ◽  
Vibration Energy ◽  
Peak Voltage ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Cantilever Structure ◽  
Sinusoidal Excitation

Most of the miniaturized electromagnetic vibrational energy harvesters (EVEHs) are based on oscillating proof mass suspended by several springs or a cantilever structure. Such structural feature limits the miniaturization of the device’s footprint. This paper presents an EVEH device based on a torsional vibrating magnet over a stack of flexible planar coils. The torsional movement of the magnet is enabled by microfabricated silicon torsional springs, which effectively reduce the footprint of the device. With a size of 1 cm × 1 cm × 1.08 cm, the proposed EVEH is capable of generating an open-circuit peak-to-peak voltage of 169 mV and a power of 6.9 μW, under a sinusoidal excitation of ±0.5 g (g = 9.8 m/s2) and frequency of 96 Hz. At elevated acceleration levels, the maximum peak-to-peak output voltage is 222 mV under the acceleration of 7 g (±3.5 g).

Modeling of Hybrid Piezoelectrodynamic Generators

2014 ◽  
Vol 1 (3-4) ◽  
Author(s):  
Henrik Zessin ◽  
Loreto Mateu ◽  
Peter Spies
Keyword(s):  
Low Power ◽  
Power Management ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Mechanical Vibrations ◽  
Energy Harvesters ◽  
Piezoelectric Generator ◽  
Electrical Part ◽  
Hybrid Generator ◽  
Phase Relationships

AbstractVibrational energy harvesters are used for collecting electrical power from mechanical vibrations and supplying low power applications. Combining a piezoelectric generator with an electrodynamic generator creates a hybrid piezoelectrodynamic generator. In this paper, a model for this hybrid generator is proposed. The model allows the accurate simulation of the mechanical and electrical part of the generator. It also makes it possible to analyze the waveforms and phase relationships of the two electrical outputs of the hybrid generator and thus simulate power management circuits and their feedback on the generator.

Model Reduction of Piezoelectric Energy Harvesters Subject to Band-Limited, Stochastic Base Excitation

2012 ◽  
Author(s):  
Adam M. Wickenheiser
Keyword(s):  
White Noise ◽  
Design Optimization ◽  
Broadband Noise ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Energy Harvesters ◽  
White Noise Excitation ◽  
Single Degree ◽  
Piezoelectric Energy ◽  
Band Limited

In many scenarios where vibration energy harvesting can be utilized — particularly those involving bio-motions or environmental disturbances — energy sources are broadband and non-stationary. On the other hand, design procedures have been predominantly developed for harmonic or white noise excitation, specifically for single degree of freedom approximations of the transducer. In this paper, a general approach for design optimization of cantilevered, piezoelectric energy harvesters in the presence of band-limited, white-noise excitation is outlined. For this study, human and vehicular motions are considered; these complex waveforms are distilled into a small set of dominant features with regard to their impact on the power output of the device. Criteria based on modal participation factors, including pre-filtering of the disturbance, are used in guiding the reduction of the input and plant degrees of freedom in order to make the design optimization problem tractable. This process determines the error in assuming a low-order model for the transducer in the presence of broadband noise that may excite multiple modes of vibration. Furthermore, this study considers the quantitative impact of charge cancellation in higher modes and the benefits of inserting multiple electrodes along the length. To illustrate these methods, energy harvesters are designed for acceleration data collected from walking and car idling. It is shown that a simple method that is a generalization of naïve approaches that assume harmonic or white noise excitation and a single degree of freedom can determine which simplifications are appropriate and the inaccuracies that can be expected from them.

An analytic study of vibrational energy harvesting using piezoelectric tiles in stairways subjected to human traffic

2018 ◽  
Vol 30 (5) ◽  
pp. 968-985
Author(s):  
CONNOR EDLUND ◽  
SUBRAMANIAN RAMAKRISHNAN
Keyword(s):  
Energy Harvesting ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Random Excitation ◽  
Analytical Models ◽  
Practical Applications ◽  
Type Iii ◽  
Pedestrian Traffic ◽  
Type V ◽  
Vibrational Energy Harvesting

This work investigates analytically, the use of piezoelectric tiles placed on stairways for vibrational energy harvesting – harnessing electrical power from natural vibrational phenomena – from pedestrian footfalls. While energy harvesting from pedestrian traffic along flat pathways has been studied in the linear regime and realised in practical applications, the greater amounts of energy naturally expended in traversing stairways suggest better prospects for harvesting. Considering the characteristics of two types of commercially available piezoelectric tiles – Navy Type III and Navy Type V – analytical models for the coupled electromechanical system are formulated. The harvesting potential of the tiles is then studied under conditions of both deterministic and carefully developed random excitation profiles for three distinct cases: linear, monostable nonlinear and an array of monostable nonlinear tiles on adjacent steps with linear coupling between them. The results indicate enhanced power output when the tiles are: (1) placed on stairways, (2) uncoupled and (3) subjected to excitation profiles with stochastic frequency. In addition, the Navy Type V tiles are seen to outperform the Navy Type III tiles. Finally, the strongly nonlinear regime outperforms the linear one suggesting that the realisation of commercially available piezoelectric tiles with appropriately tailored nonlinear characteristics will likely have a significant impact on energy harvesting from pedestrian traffic.

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