scholarly journals Models for 31-Mode PVDF Energy Harvester for Wearable Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jingjing Zhao ◽  
Zheng You
Keyword(s):  
Energy Harvester ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Theoretical Models ◽  
Human Motion ◽  
Wearable Electronics ◽  
Portable Power ◽  
Renewable Power ◽  
Piezoelectric Energy ◽  
Better Than

Currently, wearable electronics are increasingly widely used, leading to an increasing need of portable power supply. As a clean and renewable power source, piezoelectric energy harvester can transfer mechanical energy into electric energy directly, and the energy harvester based on polyvinylidene difluoride (PVDF) operating in 31-mode is appropriate to harvest energy from human motion. This paper established a series of theoretical models to predict the performance of 31-mode PVDF energy harvester. Among them, the energy storage one can predict the collected energy accurately during the operation of the harvester. Based on theoretical study and experiments investigation, two approaches to improve the energy harvesting performance have been found. Furthermore, experiment results demonstrate the high accuracies of the models, which are better than 95%.

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 Cellular Polyolefin Composites as Piezoelectric Materials: Properties and Applications

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2698
Author(s):  
Ewa Klimiec ◽  
Halina Kaczmarek ◽  
Bogusław Królikowski ◽  
Grzegorz Kołaszczyński
Keyword(s):  
Integrated Circuits ◽  
Piezoelectric Materials ◽  
Mechanical Energy ◽  
Constant Electric Field ◽  
Electric Energy ◽  
High Sensitivity ◽  
Human Motion ◽  
Piezoelectric Polymers ◽  
High Durability ◽  
Mineral Fillers

Piezoelectric polymers characterized by flexibility are sought for applications in microelectronics, medicine, telecommunications, and everyday devices. The objective of this work was to obtain piezoelectric polymeric composites with a cellular structure and to evaluate their usefulness in practice. Composites based on polyolefins (isotactic-polypropylene and polyethylene) with the addition of aluminosilicate fillers were manufactured by extrusion, and then polarized in a constant electric field at 100 V/µm. The content of mineral fillers up to 10 wt% in the polymer matrix enhances its electric stability and mechanical strength. The value of the piezoelectric coefficient d33 attained ~150 pC/N in the range of lower stresses and ~80 pC/N in the range of higher stresses, i.e., at ~120 kPa. The materials exhibited high durability in time, therefore, they can be used as transducers of mechanical energy of the human motion into electric energy. It was demonstrated that one shoe insert generates an energy of 1.1 mJ after a person walks for 300 s. The miniaturized integrated circuits based on polyolefin composites may be applied for the power supply of portable electronics. Due to their high sensitivity, they can be recommended for measuring the blood pulse.

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.

Topology Optimization Design of Implantable Energy Harvesting Device

2011 ◽  
Vol 55-57 ◽  
pp. 498-503
Author(s):  
Bin Zheng ◽  
Liang Ping Luo
Keyword(s):  
Topology Optimization ◽  
Energy Harvesting ◽  
Optimization Design ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Structure Design ◽  
Mems Devices ◽  
Sensors And Actuators ◽  
Piezoelectric Energy ◽  
Piezoelectric Structure

When designing implantable biomedical MEMS devices, we must provide electric power source with long life and small size to drive the sensors and actuators work. Obviously, traditional battery is not a good choice because of its large size, limited lifetime and finite power storage. Living creatures all have non-electric energy sources, like mechanical energy from heart beat and pulse. Piezoelectric structure can convert mechanical energy to electric energy. In the same design condition, the more electric energy is generated, the better the piezoelectric structure design. This paper discusses the topology optimization method for the most efficient implantable piezoelectric energy harvesting device. Finally, a design example based on the proposed method is given and the result is discussed.

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.

Flexible and multi-directional piezoelectric energy harvester for self-powered human motion sensor

2018 ◽  
Vol 27 (3) ◽  
pp. 035001 ◽  
Author(s):  
Min-Ook Kim ◽  
Soonjae Pyo ◽  
Yongkeun Oh ◽  
Yunsung Kang ◽  
Kyung-Ho Cho ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Human Motion ◽  
Motion Sensor ◽  
Piezoelectric Energy ◽  
Self Powered

Energy Harvesting Characteristics of Conical Shells

2011 ◽  
Author(s):  
H. Li ◽  
S. D. Hu ◽  
H. S. Tzou
Keyword(s):  
Energy Harvesting ◽  
Conical Shell ◽  
Energy Harvester ◽  
Electric Energy ◽  
Electrical Energy ◽  
Open Circuit ◽  
Ambient Vibration ◽  
Circular Membrane ◽  
Shell Surface ◽  
Piezoelectric Energy

Piezoelectric energy harvesting has experienced significant growth over the past few years. Various harvesting structures have been proposed to convert ambient vibration energies to electrical energy. However, these harvester’s base structures are mostly beams and some plates. Shells have great potential to harvest more energy. This study aims to evaluate a piezoelectric coupled conical shell based energy harvester system. Piezoelectric patches are laminated on the conical shell surface to convert vibration energy to electric energy. An open-circuit output voltage of the conical energy harvester is derived based on the thin-shell theory and the Donnel-Mushtari-Valsov theory. The open-circuit voltage and its derived energy consists of four components respectively resulting from the meridional and circular membrane strains, as well as the meridional and circular bending strains. Reducing the surface of the harvester to infinite small gives the spatial energy distribution on the shell surface. Then, the distributed modal energy harvesting characteristics of the proposed PVDF/conical shell harvester are evaluated in case studies. The results show that, for each mode with unit modal amplitude, the distribution depends on the mode shape, harvester location, and geometric parameters. The regions with high strain outputs yield higher modal energies. Accordingly, optimal locations for the PVDF harvester can be defined. Also, when modal amplitudes are specified, the overall energy of the conical shell harvester can be calculated.

Flexible piezoelectric energy harvester with an ultrahigh transduction coefficient by the interconnected skeleton design strategy

Nanoscale ◽  
2020 ◽  
Vol 12 (24) ◽  
pp. 13001-13009
Author(s):  
Yijin Hao ◽  
Yudong Hou ◽  
Jing Fu ◽  
Xiaole Yu ◽  
Xin Gao ◽  
...  
Keyword(s):  
Composite Materials ◽  
Energy Harvester ◽  
Design Strategy ◽  
Piezoelectric Energy ◽  
Better Than

The freeze-casted 2-2 type piezocomposite has an ultrahigh transduction coefficient of 58 213 × 10−15 m2 N−1, which is significantly better than those of previously reported composite materials.

scholarly journals Development and Validation of an Enhanced Coupled-Field Model for PZT Cantilever Bimorph Energy Harvester

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Long Zhang ◽  
Keith A. Williams ◽  
Zhengchao Xie
Keyword(s):  
Energy Harvester ◽  
Field Model ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Open Circuit ◽  
Conservation Of Energy ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Comparison Results ◽  
Coupled Field

The power source with the limited life span has motivated the development of the energy harvesters that can scavenge the ambient environment energy and convert it into the electrical energy. With the coupled field characteristics of structure to electricity, piezoelectric energy harvesters are under consideration as a means of converting the mechanical energy to the electrical energy, with the goal of realizing completely self-powered sensor systems. In this paper, two previous models in the literatures for predicting the open-circuit and close-circuit voltages of a piezoelectric cantilever bimorph (PCB) energy harvester are first described, that is, the mechanical equivalent spring mass-damper model and the electrical equivalent circuit model. Then, the development of an enhanced coupled field model for the PCB energy harvester based on another previous model in the literature using a conservation of energy method is presented. Further, the laboratory experiments are carried out to evaluate the enhanced coupled field model and the other two previous models in the literatures. The comparison results show that the enhanced coupled field model can better predict the open-circuit and close-circuit voltages of the PCB energy harvester with a proof mass bonded at the free end of the structure in order to increase the energy-harvesting level of the system.

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