scholarly journals Energy Localization through Locally Resonant Materials

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3016 ◽  
Author(s):  
Marco Moscatelli ◽  
Claudia Comi ◽  
Jean-Jacques Marigo
Keyword(s):  
Energy Harvester ◽  
Mechanical Energy ◽  
Plane Waves ◽  
Characteristic Dimension ◽  
Analytic Description ◽  
Internal Cavity ◽  
Energy Localization ◽  
Fabry Perot ◽  
Unit Cells ◽  
Separation Of Scales

Among the attractive properties of metamaterials, the capability of focusing and localizing waves has recently attracted research interest to establish novel energy harvester configurations. In the same frame, in this work, we develop and optimize a system for concentrating mechanical energy carried by elastic anti-plane waves. The system, resembling a Fabry-Pérot interferometer, has two barriers composed of Locally Resonant Materials (LRMs) and separated by a homogeneous internal cavity. The attenuation properties of the LRMs allow for the localization of waves propagating at particular frequencies. With proper assumptions on the specific ternary LRMs, the separation of scales (between the considered wave lengths and the characteristic dimension of the employed unit cells) enables the use of a two-scale asymptotic technique for computing the effective behavior of the employed LRMs. This leads to a complete analytic description of the motion of the system. Here we report the results achieved by optimizing the geometry of the system for obtaining a maximum focusing of the incoming mechanical energy. The analytic results are then validated through numerical simulations.

Optimization of spiral-shaped piezoelectric energy harvester using Taguchi method

2017 ◽  
Vol 24 (19) ◽  
pp. 4484-4491 ◽  
Author(s):  
R Tikani ◽  
L Torfenezhad ◽  
M Mousavi ◽  
S Ziaei-Rad
Keyword(s):  
Taguchi Method ◽  
Energy Harvester ◽  
Piezoelectric Materials ◽  
Mechanical Energy ◽  
Experimental Investigations ◽  
Optimum Level ◽  
Low Frequencies ◽  
Piezoelectric Energy ◽  
Resonance Frequencies ◽  
Design Values

Nowadays, environmental energy resources, especially mechanical vibrations, have attracted the attention of researchers to provide energy for low-power electronic circuits. A common method for environmental mechanical energy harvesting involves using piezoelectric materials. In this study, a spiral multimode piezoelectric energy harvester was designed and fabricated. To achieve wide bandwidth in low frequencies (below 15 Hz), the first three resonance frequencies of the beam were designed to be close to each other. To do this, the five lengths of the substrate layer were optimized by the Taguchi method, using an L27 orthogonal array. Each experiment of the Taguchi method was then simulated in ANSYS software. Next, the optimum level of each design variable was obtained. A test rig was then constructed based on the optimum design values and some experimental investigations were conducted. A good correlation was observed between measured and the finite element results.

scholarly journals Non-reciprocal robotic metamaterials

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Martin Brandenbourger ◽  
Xander Locsin ◽  
Edan Lerner ◽  
Corentin Coulais
Keyword(s):  
Skin Effect ◽  
Mechanical Energy ◽  
Standing Waves ◽  
Control Loops ◽  
Active Metamaterials ◽  
Mechanical Metamaterials ◽  
Wide Range ◽  
Propagating Waves ◽  
Mechanical Analogue ◽  
Unit Cells

Abstract Non-reciprocal transmission of motion is potentially highly beneficial to a wide range of applications, ranging from wave guiding to shock and vibration damping and energy harvesting. To date, large levels of non-reciprocity have been realized using broken spatial or temporal symmetries, yet mostly in the vicinity of resonances, bandgaps or using nonlinearities, thereby non-reciprocal transmission remains limited to narrow ranges of frequencies or input magnitudes and sensitive to attenuation. Here, we create a robotic mechanical metamaterials wherein we use local control loops to break reciprocity at the level of the interactions between the unit cells. We show theoretically and experimentally that first-of-their-kind spatially asymmetric standing waves at all frequencies and unidirectionally amplified propagating waves emerge. These findings realize the mechanical analogue of the non-Hermitian skin effect. They significantly advance the field of active metamaterials for non hermitian physics and open avenues to channel mechanical energy in unprecedented ways.

scholarly journals Splitting of neutral mechanical plane of conformal, multilayer piezoelectric mechanical energy harvester

2015 ◽  
Vol 107 (4) ◽  
pp. 041905 ◽  
Author(s):  
Yewang Su ◽  
Shuang Li ◽  
Rui Li ◽  
Canan Dagdeviren
Keyword(s):  
Energy Harvester ◽  
Mechanical Energy

A Flexible Composite Mechanical Energy Harvester from a Ferroelectric Organoamino Phosphonium Salt

2018 ◽  
Vol 130 (29) ◽  
pp. 9192-9196 ◽  
Author(s):  
Thangavel Vijayakanth ◽  
Anant Kumar Srivastava ◽  
Farsa Ram ◽  
Priyangi Kulkarni ◽  
Kadhiravan Shanmuganathan ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Phosphonium Salt ◽  
Mechanical Energy

Modeling and optimization of a wide-band piezoelectric energy harvester for smart building structures

2020 ◽  
Vol 11 (02) ◽  
pp. 2050009
Author(s):  
Prateek Asthana ◽  
Gargi Khanna
Keyword(s):  
Resonant Frequency ◽  
Energy Harvester ◽  
Proof Mass ◽  
Mechanical Energy ◽  
Wide Band ◽  
Electrical Energy ◽  
Sensor Nodes ◽  
Ambient Vibrations ◽  
Band Energy ◽  
Piezoelectric Energy

Piezoelectric energy harvesting refers to conversion of mechanical energy into usable electrical energy. In the modern connected world, wireless sensor nodes are scattered around the environment. These nodes are powered by batteries. Batteries require regular replacement, hence energy harvesters providing continuous autonomous power are used to power these sensor nodes. This work provides two different fixation modes for the resonant frequency for the two modes. Variation in geometric parameter and their effect on resonant frequency and output power have been analyzed. These harvesters capture a wide-band of ambient vibrations and convert them into usable electrical energy. To capture random ambient vibrations, the harvester used is a wide-band energy harvester based on conventional seesaw mechanism. The proposed structure operates on first two resonant frequencies in comparison to the conventional cantilever system working on first resonant frequency. Resonance frequency, as well as response to a varying input vibration frequency, is carried out, showing better performance of seesaw cantilever design. In this work, modeling of wide-band energy harvester with proof mass is being performed. Position of proof mass plays a key role in determining the resonant frequency of the harvester. Placing the proof mass near or away from fixed end results in increase and decrease in stress on the piezoelectric layer. Hence, to avoid the breaking of cantilever, the position of proof mass has been analyzed.

scholarly journals Modified Luneburg Lens Based on Metamaterials

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Haibing Chen ◽  
Qiang Cheng ◽  
Aihua Huang ◽  
Junyan Dai ◽  
Huiying Lu ◽  
...  
Keyword(s):  
Plane Waves ◽  
Microwave Frequency ◽  
Refractive Index Profile ◽  
Experimental Characterization ◽  
Index Profile ◽  
Cylindrical Waves ◽  
Unit Cells ◽  
Luneburg Lens ◽  
Luneberg Lens

We present the design, fabrication, and experimental characterization of a modified two-dimensional Luneburg lens based on bulk metamaterials. The lens is composed by a number of concentric layers. By varying the geometric dimensions of unit cells in each layer, the gradient refractive index profile required for the modified Luneburg lens can be achieved. The cylindrical waves generated from a point source at the focus point of the lens could be transformed into plane waves as desired in the microwave frequency. The proposed modified Luneburg lens can realize wide-angle beam scanning when the source moves along the circumferential direction inside the lens. Numerical and experimental results validate the performance of the modified Luneberg lens.

Mechanical Energy Harvester With Ultralow Threshold Rectification Based on SSHI Nonlinear Technique

2009 ◽  
Vol 56 (4) ◽  
pp. 1048-1056 ◽  
Author(s):  
L. Garbuio ◽  
M. Lallart ◽  
D. Guyomar ◽  
C. Richard ◽  
D. Audigier
Keyword(s):  
Energy Harvester ◽  
Mechanical Energy ◽  
Nonlinear Technique

Multiple Resonances Piezoelectric Energy Harvesting Generator

2009 ◽  
Author(s):  
Shaofan Qi ◽  
Roger Shuttleworth ◽  
S. Olutunde Oyadiji
Keyword(s):  
Energy Harvesting ◽  
Energy Harvester ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Limited Bandwidth ◽  
Piezo Element ◽  
Piezoelectric Energy ◽  
Wide Range ◽  
Environmental Vibration ◽  
Design And Testing

Energy harvesting is the process of converting low level ambient energy into usable electrical energy, so that remote electronic instruments can be powered without the need for batteries or other supplies. Piezoelectric material has the ability to convert mechanical energy into electrical energy, and cantilever type harvesters using this material are being intensely investigated. The typical single cantilever energy harvester design has a limited bandwidth, and is restricted in ability for converting environmental vibration occurring over a wide range of frequencies. A multiple cantilever piezoelectric generator that works over a range of frequencies, yet has only one Piezo element, is being investigated. The design and testing of this novel harvester is described.

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