Enhancement of energy harvesting performance for a piezoelectric cantilever using a spring mass suspension

A spring-mass suspension is proposed in this paper for enhancing vibration energy harvesting performances of piezoelectric cantilevers. The suspension is inserted between the piezoelectric cantilever and the vibration base. Two key criteria are proposed for designing the present structure towards simultaneous broadband and intensive energy harvesting. On the one hand, the natural frequency of the spring-mass suspension is tuned close to that of the piezoelectric beam. On the other hand, the inertial mass of the suspension is chosen much greater than the cantilever mass. The amplification of the dynamic response over a broader frequency band of the proposed configuration is validated via vibration analyses. A prototype device in accordance with the proposed design is subsequently developed for experimental evaluations. The present structure widens the effective bandwidth from 7.6 Hz to 22.2 Hz, while increasing the maximum harvested power from 0.01436 mW/g to 0.4406 mW/g compared to the conventional cantilevered energy harvester

Modeling and Analysis of Bimorph Piezoelectromagnetic Energy Harvester

Piezoelectric energy harvesting is one of the methods of obtaining energy from environment. It is often a cantilever beam with or without tip mass poled with piezoelectric material. The fixed end of cantilever beam is subjected to either base excitation or translation as occurring from an environmental source such as automobile or vibrating engine. The piezoelectric energy harvester generates maximum energy when it is excited at resonance frequency and the little variation below or above the resonance frequency will drastically reduce the power output. In this line, present work studies a broadband nonlinear piezoelectric energy harvester driven by periodic and random oscillations. The simulated response to the base excitation is illustrated in terms of harvested power. By introducing magnetic force, we can broaden the frequency zone so as to capture more energy even the beam do not vibrate close to source frequency. A magnetic tip is included at the free end of the cantilever beam and is excited by two permanent magnets fixed on either sides laterally. The symmetric bimorph cantilever beam piezoelectric energy harvester with magnetic tip is modeled as Single-degree of freedom lumped parameter system. The time domain history and frequency response diagrams for the cantilever displacement, voltage and power at the constant load resistance gives a stability picture as well as the amount of energy harvested. The effect of various parameters of energy harvester system on induced voltage and output power is studied. The distributed parameter model is formulated by using Euler-Bernoulli beam theory and Galerkin’s approximation technique. The finite element modeling equations are presented with piezoelectric coupling terms. Novelty in the work include; (i) adding a magnetic force in the system to make it as broadband harvester (ii) validation of approximation solutions with spring-mass modeling

Multifrequency piezoelectric energy harvester based on polygon-shaped cantilever array

This paper focuses on numerical and experimental investigations of a novel design piezoelectric energy harvester. Investigated harvester is based on polygon-shaped cantilever array and employs multifrequency operating principle. It consists of eight cantilevers with irregular design of cross-sectional area. Cantilevers are connected to each other by specific angle to form polygon-shaped structure. Moreover, seven seismic masses with additional lever arms are added in order to create additional rotation moment. Numerical investigation showed that piezoelectric polygon-shaped energy harvester has five natural frequencies in the frequency range from 10 Hz to 240 Hz, where the first and the second bending modes of the cantilevers are dominating. Maximum output voltage density and energy density equal to 50.03 mV/mm3 and 604 μJ/mm3, respectively, were obtained during numerical simulation. Prototype of piezoelectric harvester was made and experimental investigation was performed. Experimental measurements of the electrical characteristics showed that maximum output voltage density, energy density, and output power are 37.5 mV/mm3, 815.16 μJ/mm3, and 65.24 μW, respectively

IMPACT-BASED PIEZOELECTRIC ENERGY HARVESTING SYSTEM EXCITED FROM DIESEL ENGINE SUSPENSION

Vibration energy harvesting systems are using real ambient sources of vibration excitation. In our paper, we study the dynamical voltage response of the piezoelectric vibrational energy harvesting system (PVEHs) with a mechanical resonator possessing an amplitude limiter. The PVEHs consist of the cantilever beam with a piezoelectric patch. The proposed system was subjected to the inertial excitation from the engine suspension. Impacts of the beam resonator are useful to increase of system’s frequency transition band. The suitable simulations of the resonator and piezoelectric transducer are performed by using measured signal from the engine suspension. Voltage outputs of linear (without amplitude limiter) and nonlinear harvesters were compared indicating better efficiency of the nonlinear design

Piezoelectric energy harvesting solutions

This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions

Efficient harmonic oscillator chain energy harvester driven by colored noise

We study the performance of an electromechanical harmonic oscillator chain as an energy harvester to extract power from finite-bandwidth ambient random vibrations, which are modelled by colored noise. The proposed device is numerically simulated and its performance assessed by means of the net electrical power generated and its efficiency in converting the external noise-supplied power into electrical power. Our main result is a much enhanced performance, both in the net electrical power delivered and in efficiency, of the harmonic chain with respect to the popular single oscillator resonator. Our numerical findings are explained by means of an analytical approximation, in excellent agreement with numerics

Piezoelectric Energy Harvesting System Via Impact And Vibration – A Review

Recently, the vibrational energy harvesting devices have been studied and developed significantly. Although battery is the main power source for electronic devices, it still has some limitations, particularly its life time. Piezoelectric transducer is one of the devices that can be used for the vibration energy harvesting system. It has higher power density compared to the others. A comprehensive review on piezoelectric energy harvesting system is discussed and presented in this paper. The techniques of the piezoelectric energy harvester such as impact and vibration modes are reviewed. The power generator developed for the impact-based piezoelectric energy harvester is addressed in this paper. It can be concluded that the piezoelectric energy harvesting system can generate output power in the range of 34.6nW to 1.34W