scholarly journals Multiresonant Frequency Piezoelectric Energy Harvesters Integrated with High Sensitivity Piezoelectric Accelerometer for Bridge Health Monitoring Applications

2017 ◽  
Vol 2017 ◽  
pp. 1-23 ◽  
Author(s):  
Prathish Raaja Bhaskaran ◽  
Joseph Daniel Rathnam ◽  
Sumangala Koilmani ◽  
Kavitha Subramanian

Wireless Structural Health Monitoring (WSHM) is a less expensive but efficient mode of health monitoring. However, it needs frequent change of batteries since remote WSHM consumes large power. The best scientific solution to this problem is to employ energy harvesters integrated along with the vibration sensors in the same substrate so that the battery is recharged by the energy harvested during vibrations caused by the passing vehicles in bridges. In this work, an attempt has been made to design an energy harvester and a micro accelerometer integrated chip. Civil structures have low natural frequencies and therefore low bandwidth design is adopted to maximize the harvested energy and accelerometer sensitivity. The other special feature of the proposed design is its ability to provide further increase in energy harvesting by the parallel operation of an array of energy harvesters with closely spaced natural frequencies. The studies show that the natural frequencies of the harvesters should be less than that of the structure in healthy condition. Simulation studies conducted on these devices show that it is possible to harvest a maximum power of 2.283 mW/g. The integrated micro accelerometer is also capable of giving a sensitivity of 27.67 V/g with appreciable improvement in other performance indices.

Author(s):  
Alper Erturk ◽  
Daniel J. Inman

Harvesting of vibration energy has been investigated by numerous researchers over the last decade. The research motivation in this field is due to the reduced power requirement of small electronic components such as wireless sensor networks used in monitoring applications. The ultimate goal is to power such devices by using the waste vibration energy available in their environment so that the maintenance requirement for battery replacement is minimized. Among the basic transduction mechanisms that can be used for vibration-to-electricity conversion, piezoelectric transduction has received the most attention due to the large power densities and ease of application of piezoelectric materials. Typically, a piezoelectric energy harvester is a cantilevered beam with one or two piezoceramic layers and the source of excitation is the base motion in the transverse direction. This paper presents general formulations for electromechanical modeling of base-excited piezoelectric energy harvesters with symmetric and asymmetric laminates. The electromechanical derivations are given using the assumed-modes method under the Euler-Bernoulli, Rayleigh and Timoshenko beam assumptions in three sections. The formulations account for an independent axial displacement variable in all cases. Comparisons are provided against the analytical solution given by the authors for symmetric laminates and convergence of the assumed-modes solution to the analytical solution with the increasing number of modes is shown. Experimental validations are also presented by comparing the electromechanical frequency response functions derived here against the experimentally obtained ones. The electromechanical assumed-modes formulations given here can be used for modeling of piezoelectric energy harvesters with asymmetric laminates as well as those with moderate thickness and varying geometry in the axial direction.


2019 ◽  
Vol 30 (18-19) ◽  
pp. 2894-2907
Author(s):  
Scott Townsend ◽  
Stephen Grigg ◽  
Renato Picelli ◽  
Carol Featherston ◽  
Hyunsun Alicia Kim

Aircraft structures exhibit localized vibrations over a wide range of frequencies. Such vibrations can be used to power sensors which then monitor the health of the structure. Conventional vibrational piezoelectric harvesting involves optimizing the harvester for one distinct frequency. The aim of this work is to design a wireless vibrational piezoelectric system capable of energy harvesting in the range of 100–500 Hz by tailoring the resonant behavior of cantilever structures. We herein employ a model capable of predicting the performance of a piezoelectric cantilever retrofit on a structural health monitoring sensor and then formulate a design optimization problem and solve with the level set topology optimization method. The designs are verified through fabrication of experimental prototypes.


2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Anup Pydah ◽  
R. C. Batra

We present a novel beam-based vibration energy harvester, and use a structural tailoring concept to tune its natural frequencies. Using a solution of the Euler–Bernoulli beam theory equations, verified with finite element (FE) solutions of shell theory equations, we show that introducing folds or creases along the span of a slender beam, varying the fold angle at a crease, and changing the crease location helps tune the beam natural frequencies to match an external excitation frequency and maximize the energy harvested. For a beam clamped at both ends, the first frequency can be increased by 175% with a single fold. With two folds, selective frequencies can be tuned, leaving others unchanged. The number of folds, their locations, and the fold angles act as tuning parameters that provide high sensitivity and controllability of the frequency response of the harvester. The analytical model can be used to quickly optimize designs with multiple folds for anticipated external frequencies.


2021 ◽  
Vol 13 (5) ◽  
pp. 2865 ◽  
Author(s):  
Sungryong Bae ◽  
Pilkee Kim

In this study, optimization of the external load resistance of a piezoelectric bistable energy harvester was performed for primary harmonic (period-1T) and subharmonic (period-3T) interwell motions. The analytical expression of the optimal load resistance was derived, based on the spectral analyses of the interwell motions, and evaluated. The analytical results are in excellent agreement with the numerical ones. A parametric study shows that the optimal load resistance depended on the forcing frequency, but not the intensity of the ambient vibration. Additionally, it was found that the optimal resistance for the period-3T interwell motion tended to be approximately three times larger than that for the period-1T interwell motion, which means that the optimal resistance was directly affected by the oscillation frequency (or oscillation period) of the motion rather than the forcing frequency. For broadband energy harvesting applications, the subharmonic interwell motion is also useful, in addition to the primary harmonic interwell motion. In designing such piezoelectric bistable energy harvesters, the frequency dependency of the optimal load resistance should be considered properly depending on ambient vibrations.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 803
Author(s):  
Zhongjie Li ◽  
Chuanfu Xin ◽  
Yan Peng ◽  
Min Wang ◽  
Jun Luo ◽  
...  

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.


Author(s):  
Virgilio J Caetano ◽  
Marcelo A Savi

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.


Author(s):  
Guangya Ding ◽  
Hongjun Luo ◽  
Jun Wang ◽  
Guohui Yuan

A novel lever piezoelectric energy harvester (LPEH) was designed for installation in an actual roadway for energy harvesting. The model incorporates a lever module that amplifies the applied traffic load and transmits it to the piezoelectric ceramic. To observe the piezoelectric growth benefits of the optimized LPEH structure, the output characteristics and durability of two energy harvesters, the LPEH and a piezoelectric energy harvester (PEH) without a lever, were measured and compared by carrying out piezoelectric performance tests and traffic model experiments. Under the same loading condition, the open circuit voltages of the LPEH and PEH were 20.6 and 11.7 V, respectively, which represents a 76% voltage increase for the LPEH compared to the PEH. The output power of the LPEH was 21.51 mW at the optimal load, which was three times higher than that of the PEH (7.45 mW). The output power was linearly dependent on frequency and load, implying the potential application of the module as a self-powered speed sensor. When tested during 300,000 loading cycles, the LPEH still exhibited stable structural performance and durability.


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