Flexible and Robust Multilayer Micro-Vibrational Harvesters for High Acceleration Environments (original) (raw)
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Two-dimensional concentrated-stress low-frequency piezoelectric vibration energy harvesters
Vibration-based energy harvesters using piezoelectric materials have long made use of the cantilever beam structure. Surmounting the deficiencies in one-dimensional cantilever-based energy harvesters has been a major focus in the literature. In this work, we demonstrate a strategy of using two-dimensional beam shapes to harvest energy from low frequency excitations. A characteristic Zigzag-shaped beam is created to compare against the two proposed two-dimensional beam shapes, all of which occupy a 25.425.4mm2 area. In addition to maintaining the low-resonance bending frequency, the proposed beam shapes are designed with the goal of realizing a concentrated stress structure, whereby stress in the beam is concentrated in a single area where a piezoelectric layer may be placed, rather than being distributed throughout the beam. It is shown analytically, numerically, and experimentally that one of the proposed harvesters is able to provide significant increase in power production, when the base acceleration is set equal to 0.1 g, with only a minimal change in the resonant frequency compared to the current state-of-the-art Zigzag shape. This is accomplished by eliminating torsional effects, producing a more pure bending motion that is necessary for high electromechanical coupling. In addition, the proposed harvesters have a large effective beam tip whereby large tip mass may be placed while retaining a low-profile, resulting in a low volume harvester and subsequently large power density.
Sensors and Actuators A: Physical, 2019
Highlights A novel MEMS based Si bulk micromachining process has been developed to fabricate P(VDF-TrFE) micro-cantilevers and beams successfully for the first time. Design and simulation of micro-cantilevers and beams were carried out using Comsol Multiphysics. Micro-cantilevers and beams were characterized with Laser Doppler Vibrometer and resonant frequency, voltage and power output have been measured. This novel process has potential for the development of P(VDF-TrFE) micro-cantilevers and beams for low frequency vibration sensor and energy harvester applications.
Design and Testing of a Compact Piezoelectric Energy Harvester
Piezoelectric materials generate electricity when they are subjected to dynamic strain. Much energy harvesting research has been performed with PZT type ceramics based piezoelectric transducers because of their relatively large electrical response to mechanical vibrations. However, notwithstanding their relatively low piezoelectric coefficients, piezoelectric polymers such as poly(vinylidene fluoride) (PVDF) hold promise as energy harvesting materials due to their flexibility and mechanical strength. These properties make them ideal candidates for use in the more diverse applications. To generate significant power, these polymers must be used in the most efficient manner possible in the structures. With these factors in consideration, a novel cantilever system was designed and examined for its performance. The highest power output accomplished was 0.109 W for a particular structure with a broad frequency response operating in the 31 mode.
Japanese Journal of Applied Physics, 2017
We investigated piezoelectric vibration energy harvesters with poly(vinylidene fluoride/trifluoroethylene) films and the improved power generation from using multistacked and stretched ferroelectric films on the cantilevers. The energy harvesters generated electric power with a resonant frequency approximately 25 Hz, which corresponded to the ambient vibration. The power density of four-layered harvesters was estimated to be 2.5 μW/mm 3 , which was quite larger than that of previous harvesters. The output power of stretched-film harvesters was 3.6 times the output obtained from unstretched films. Also, because organic ferroelectric films are flexible, the resonant frequency of each harvester was practically constant even when using the techniques of multistacking and stretching.
A Review of Vibration-Based Piezoelectric Energy Harvesters.
International Journal of Engineering Sciences & Research Technology, 2014
Piezoelectric energy harvesting technology has received a great attention during the last decade to activate low power microelectronic devices. Piezoelectric cantilever beam energy harvesters are commonly used to convert ambient vibration into electrical energy. In this paper we reviewed the work carried out by researchers during the last ten years. The improvements in experimental results obtained in the vibration-based piezoelectric energy harvesters show very good scope for piezoelectric harvesters in the field of power in the near future.
Development of Vibration Piezoelectric Harvesters by the Optimum Design of Cantilever Structures
Nanogenerators [Working Title]
Piezoelectric energy harvesting is a way of converting waste mechanical energy into usable electrical form. The selection of mechanical devices for conversion of mechanical to electrical energy is a significant part of vibration energy harvesting. The articles provide designing and optimization of a cantilever piezoelectric energy harvester. At first, is the selection of best mechanical device for energy harvesting application. A cantilever without proof mass is then analyzed for the selection of substrate, and piezoelectric material also plays a key role in the performance of the device. Aluminum is selected as a substrate, while zinc oxide acts as the piezoelectric layer. Addition of proof mass reduces the resonant frequency of the device to about 51 Hz as compared to 900 Hz for an aluminum cantilever beam. An electromechanical study shows an active conversion of mechanical input energy to electrical output energy. Power frequency response functions of the resultant structure are able to generate 0.47 mW power having 6.8 μA current at 1 g input acceleration.
IJERT-Modelling, Fabrication and Characterization of a Piezoelectric Vibration Energy Harvester
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/modelling-fabrication-and-characterization-of-a-piezoelectric-vibration-energy-harvester https://www.ijert.org/research/modelling-fabrication-and-characterization-of-a-piezoelectric-vibration-energy-harvester-IJERTV3IS10117.pdf In the immediate surroundings of our daily life, we can find a lot of places where the energy in the form of vibration is being wasted. Therefore, we have enormous opportunities to utilize the same. Piezoelectric character of matter enables us to convert this mechanical vibration energy into electrical energy which can be stored and used to power other device, instead of being wasted. This work is done to realize both actuator and sensor in a cantilever beam based on piezoelectricity. The sensor part is called vibration energy harvester. The numerical analyses were performed for the cantilever beam using the commercial package ANSYS and MATLAB. The cantilever beam is realized by taking a plate and fixing its one end between two massive plates. Two PZT patches were glued to the beam on its two faces. Experiments were performed using data acquisition system (DAQ) and LABVIEW software for actuating and sensing the vibration of the cantilever beam.
Development of MEMS-based Piezoelectric Vibration Energy Harvesters
Conference Proceedings of the Society for Experimental Mechanics Series, 2011
In this paper, the development of a first generation MEMS-based piezoelectric energy harvester capable of converting ambient vibrations into storable electrical energy is presented. The energy harvester is designed using a validated analytical electromechanical Lumped Element Model (LEM) that accurately predicts the behavior of a piezoelectric composite structure. The MEMS device is fabricated using standard sol gel PZT and conventional surface and bulk micro processing techniques. It consists of a piezoelectric composite cantilever beam (Si/SiO 2 /Ti/Pt/PZT/Pt/Au) with a proof mass at one end. A prototype device packaged in a 5 mm 2 area produces 0.98 µW rms power into an optimal resistive load when excited with an acceleration of 1 m/s 2 at its resonant frequency of 129 Hz. Although the model predicts the general behavior of the device accurately, knowledge of the overall system damping is critical to accurately predict the power output, and therefore individual dissipation mechanisms in the system must be investigated. This effort lays the foundation for future development of MEMS piezoelectric energy harvester arrays as a potential power solution for self sustaining wireless embedded systems. The electromechanical model further enables intelligent and optimal design of these energy harvesters for specific applications minimizing prototype test runs.
Modelling, Fabrication and Characterization of a Piezoelectric Vibration Energy Harvester
2014
In the immediate surroundings of our daily life, we can find a lot of places where the energy in the form of vibration is being wasted. Therefore, we have enormous opportunities to utilize the same. Piezoelectric character of matter enables us to convert this mechanical vibration energy into electrical energy which can be stored and used to power other device, instead of being wasted. This work is done to realize both actuator and sensor in a cantilever beam based on piezoelectricity. The sensor part is called vibration energy harvester. The numerical analyses were performed for the cantilever beam using the commercial package ANSYS and MATLAB. The cantilever beam is realized by taking a plate and fixing its one end between two massive plates. Two PZT patches were glued to the beam on its two faces. Experiments were performed using data acquisition system (DAQ) and LABVIEW software for actuating and sensing the vibration of the cantilever beam.
A free-standing, thick-film piezoelectric energy harvester
2008
Abstract In this paper, free-standing structures in the form of cantilevers, fabricated by using a combination of conventional thick-film technology and sacrificial layer techniques, is proposed. These structures were designed to operate as energy harvesters at low-levels of ambient vibration and were characterised using a shaker table over a range of frequencies and acceleration levels.