A Strain Distribution Based Classification of Ortho-Planar Springs: An Outlook to Piezoelectric Applications

Author(s):  
R. B. van Kempen ◽  
J. L. Herder ◽  
N. Tolou

Ortho-planar springs are characterized by their planar shape and the dominant out of plane motion. These springs have benefits for integration in piezoelectric energy harvesting transducers, because of their compactness and monolithic planar manufacturing. The operating behavior in the first low frequency bending mode can be optimized by obtaining an appropriate strain distribution. A holistic design approach is proposed that contains both the focus on strain distribution as on the low frequency dynamic operation challenge. Therefore a classification based on the strain distribution has been made, which is derived from the perspective of loading, clamping and geometry of single flexures of ortho-planar springs. A comparison based on the type of strain (bending/torsion ratio), strain inversion,off-axis stiffness and the natural frequency-normalized area factor (NFNA) has been performed. The double clamped folded configuration shows the most potential for future optimal low frequency transducer designs.

1992 ◽  
Vol 96 (10) ◽  
pp. 7229-7236 ◽  
Author(s):  
Marek Z. Zgierski ◽  
Francesco Zerbetto ◽  
Young‐Dong Shin ◽  
Edward C. Lim

2014 ◽  
Vol 976 ◽  
pp. 159-163 ◽  
Author(s):  
Roberto Ambrosio ◽  
Hector Gonzalez ◽  
Mario Moreno ◽  
Alfonso Torres ◽  
Rafael Martinez ◽  
...  

In this work is presented a study of a piezoelectric energy harvesting device used for low power consumption applications operating at relative low frequency. The structure consists of a cantilever beam made by Lead Zirconate Titanate (PZT) layer with two gold electrodes for electrical contacts. The piezoelectric material was selected taking into account its high coupling coefficients. Different structures were analyzed with variations in its dimensions and shape of the cantilever. The devices were designed to operate at the resonance frequency to get maximum electrical power output. The structures were simulated using finite element (FE) software. The analysis of the harvesting devices was performed in order to investigate the influence of the geometric parameters on the output power and the natural frequency. To validate the simulation results, an experiment with a PZT cantilever with brass substrate was carried out. The experimental data was found to be very close to simulation data. The results indicate that large structures, in the order of millimeters, are the ideal for piezoelectric energy harvesting devices providing a maximum output power in the range of mW


2019 ◽  
Vol 26 (3) ◽  
pp. 981-991
Author(s):  
Xiaobo Rui ◽  
Zhoumo Zeng ◽  
Yu Zhang ◽  
Yibo Li ◽  
Hao Feng ◽  
...  

2019 ◽  
Vol 4 (1) ◽  
pp. 3-39 ◽  
Author(s):  
Shashank Priya ◽  
Hyun-Cheol Song ◽  
Yuan Zhou ◽  
Ronnie Varghese ◽  
Anuj Chopra ◽  
...  

Abstract Piezoelectric microelectromechanical systems (PiezoMEMS) are attractive for developing next generation self-powered microsystems. PiezoMEMS promises to eliminate the costly assembly for microsensors/microsystems and provide various mechanisms for recharging the batteries, thereby, moving us closer towards batteryless wireless sensors systems and networks. In order to achieve practical implementation of this technology, a fully assembled energy harvester on the order of a quarter size dollar coin (diameter=24.26 mm, thickness=1.75 mm) should be able to generate about 100 μW continuous power from low frequency ambient vibrations (below 100 Hz). This paper reviews the state-of-the-art in microscale piezoelectric energy harvesting, summarizing key metrics such as power density and bandwidth of reported structures at low frequency input. This paper also describes the recent advancements in piezoelectric materials and resonator structures. Epitaxial growth and grain texturing of piezoelectric materials is being developed to achieve much higher energy conversion efficiency. For embedded medical systems, lead-free piezoelectric thin films are being developed and MEMS processes for these new classes of materials are being investigated. Non-linear resonating beams for wide bandwidth resonance are also reviewed as they would enable wide bandwidth and low frequency operation of energy harvesters. Particle/granule spray deposition techniques such as aerosol-deposition (AD) and granule spray in vacuum (GSV) are being matured to realize the meso-scale structures in a rapid manner. Another important element of an energy harvester is a power management circuit, which should maximize the net energy harvested. Towards this objective, it is essential for the power management circuit of a small-scale energy harvester to dissipate minimal power, and thus it requires special circuit design techniques and a simple maximum power point tracking scheme. Overall, the progress made by the research and industrial community has brought the energy harvesting technology closer to the practical applications in near future.


2017 ◽  
Vol 29 (6) ◽  
pp. 1206-1215 ◽  
Author(s):  
Donghuan Liu ◽  
Mohammed Al-Haik ◽  
Mohamed Zakaria ◽  
Muhammad R Hajj

Energy harvesting from an L-shaped structure, formed by two beams and corner and end masses, is investigated with the objective of expanding the bandwidth of the frequency range over which energy can be harvested. The structure is excited in a direction that yields the most uniform strain distribution along its main beam. The length of the auxiliary beam is varied to determine its effect on the level and breadth of the frequency range over which energy can be harvested. Results from experiments having different geometries are presented and discussed. It is determined that the frequency range over which energy can be harvested from such structures is much larger than levels harvested when using a cantilever beam. The experiments also show that L-shaped structures harvest more power when the length of the auxiliary beam is increased. On the contrary, the power density of the L-shaped structure is much smaller than that of the cantilever beam. The ability to control the bandwidth of frequency over which energy is harvested through proper adjustment of beam lengths is demonstrated.


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