Fractal-Inspired Multifrequency Structures for Piezoelectric Harvesting of Ambient Kinetic Energy

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
D. Castagnetti

Energy harvesting devices capable of converting freely-available ambient energy into electrical energy have received significant attention recently. Ambient kinetic energy is particularly attractive for conversion since it is almost ubiquitous and easily accessible. Piezoelectric energy harvesting devices are promising due to their simple configuration and high conversion efficiency. This paper studies multifrequency structures for piezoelectric energy harvesting of ambient kinetic energy, inspired by fractal geometry. Identifying such structures that are simple and efficient is challenging. We propose four fractal-inspired structures and we examine them at both micro and macroscales. We calculate their frequency response up to 100 Hz with computational modeling, and we also examine the effect of the fractal geometry iteration level. We use a cantilever plate example as a reference to validate computational results against analytical ones. A quantitative criterion to assess the harvesting efficiency of the proposed structures is introduced using the bending strain associated with each mode shape. Results show that a large number of eigenfrequencies is obtained, evenly distributed below 100 Hz, particularly in the macroscale. In addition, the iteration level of the fractal geometry affects the number and distribution of eigenfrequencies in the range of interest. Comparison with a conventional batch of cantilevers of the same size as the proposed structures shows noticeable improvement in electric charge generation.

Author(s):  
D. Castagnetti

The investigation of energy harvesting devices, able to convert freely-available ambient energy into electrical energy, has significantly improved. To this aim, the most suitable form of ambient energy is the kinetic one, being almost ubiquitous and easily accessible. Among the available conversion technologies, piezoelectric energy harvesting devices are one of the most promising, due to their simple configuration and high conversion efficiency. The most demanding task is to identify simple and efficient multi-frequency structures in the ambient vibration range. To this aim, this work proposes four fractal-inspired structures for piezoelectric energy harvesting. Through computational analysis, their frequency response is calculated up to 100Hz. The structures are examined both in the micro and macro scale and the effect of the iteration level of the fractal geometry is also assessed. By considering the bending strain associated to each mode shape, a quantitative criterion to assess the harvesting efficiency of the proposed structures is introduced.


Author(s):  
Zheqi Lin ◽  
Hae Chang Gea ◽  
Shutian Liu

Converting ambient vibration energy into electrical energy using piezoelectric energy harvester has attracted much interest in the past decades. In this paper, topology optimization is applied to design the optimal layout of the piezoelectric energy harvesting devices. The objective function is defined as to maximize the energy harvesting performance over a range of ambient vibration frequencies. Pseudo excitation method (PEM) is applied to analyze structural stationary random responses. Sensitivity analysis is derived by the adjoint method. Numerical examples are presented to demonstrate the validity of the proposed approach.


2018 ◽  
Vol 29 (18) ◽  
pp. 3572-3581
Author(s):  
Suihan Liu ◽  
Ali Imani Azad ◽  
Rigoberto Burgueño

Piezoelectric energy harvesting from ambient vibrations is well studied, but harvesting from quasi-static responses is not yet fully explored. The lack of attention is because quasi-static actions are much slower than the resonance frequency of piezoelectric oscillators to achieve optimal outputs; however, they can be a common mechanical energy resource: from large civil structure deformations to biomechanical motions. The recent advances in bio-micro-electro-mechanical systems and wireless sensor technologies are motivating the study of piezoelectric energy harvesting from quasi-static conditions for low-power budget devices. This article presents a new approach of using quasi-static deformations to generate electrical power through an axially compressed bilaterally constrained strip with an attached piezoelectric layer. A theoretical model was developed to predict the strain distribution of the strip’s buckled configuration for calculating the electrical energy generation. Results from an experimental investigation and finite element simulations are in good agreement with the theoretical study. Test results from a prototyped device showed that a peak output power of 1.33 μW/cm2 was generated, which can adequately provide power supply for low-power budget devices. And a parametric study was also conducted to provide design guidance on selecting the dimensions of a device based on the external embedding structure.


Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20527-20533 ◽  
Author(s):  
Sanggon Kim ◽  
Gerardo Ico ◽  
Yaocai Bai ◽  
Steve Yang ◽  
Jung-Ho Lee ◽  
...  

Magneto–mechano–electrical energy conversion in poly(vinylidenefluoride-trifluoroethylene) piezoelectric nanofibers integrated with magnetic nanoparticles in a particle-shape dependent manner.


Author(s):  
A. Majeed

Recent advancements in wireless technology and low power electronics such as micro electrome-chanical systems (MEMS), have created a surge of technical innovations in the eld of energy har-vesting. Piezoelectric materials, which operate on vibrations surrounding the system have becomehighly useful in terms of energy harvesting. Piezoelectricity is the ability to transform mechanicalstrain energy, mostly vibrations, to electrical energy, which can be used to power devices. This paperwill focus on energy harvesting by piezoelectricity and how it can be incorporated into various lowpower devices and explain the ability of piezoelectric materials to function as self-charging devicesthat can continuously supply power to a device and will not require any battery for future processes.


2008 ◽  
Vol 20 (5) ◽  
pp. 495-504 ◽  
Author(s):  
Jeffrey L. Kauffman ◽  
George A. Lesieutre

Piezoelectric energy harvesting devices are an attractive approach to providing remote wireless power sources. They operate by converting available vibration energy and storing it as electrical energy. Currently, most devices rely on mechanical excitation near their resonance frequency, so a low-order model which computes a few indicators of device performance is a critical design tool. Such a model, based on the assumed modes method, develops equations of motion to provide rapid computations of key device parameters, such as the natural frequencies, mode shapes, and electro-mechanical coupling coefficients. The model is validated with a comparison of its predictions and experimental data.


Author(s):  
Wander G. R. Vieira ◽  
Fred Nitzsche ◽  
Carlos De Marqui

Converting aeroelastic vibrations into electricity for low-power generation has received growing attention over the past few years. Helicopter blades with embedded piezoelectric elements can provide electrical energy to power small electronic components. In this paper, the non-linear modeling and analysis of an electromechanically coupled cantilevered helicopter blade is presented for piezoelectric energy harvesting. A resistive load is considered in the electrical domain of the problem in order to quantify the electrical power output. The non-linear electromechanical model is derived based on the Variational-Asymptotic Method (VAM). The coupled non-linear rotary system is solved in the time-domain. A generalized-α integration method is used to guarantee numerical stability, adding numerical damping at high frequencies. The electromechanical behavior of the coupled rotating blade is investigated for increasing rotating speeds (stiffening effect).


Sign in / Sign up

Export Citation Format

Share Document