scholarly journals PVDF-TrFE Electroactive Polymer Mechanical-to-Electrical Energy Harvesting Experimental Bimorph Structure

MRS Advances ◽  
2017 ◽  
Vol 2 (56) ◽  
pp. 3441-3446 ◽  
Author(s):  
William G. Kaval ◽  
Robert A. Lake ◽  
Ronald A. Coutu

ABSTRACTResearch of electrostrictive polymers has generated new opportunities for harvesting energy from the surrounding environment and converting it into usable electrical energy. Electroactive polymer (EAP) research is one of the new opportunities for harvesting energy from the natural environment and converting it into usable electrical energy. Piezoelectric ceramic based energy harvesting devices tend to be unsuitable for low-frequency mechanical excitations such as human movement. Organic polymers are typically softer and more flexible therefore translated electrical energy output is considerably higher under the same mechanical force. In addition, cantilever geometry is one of the most used structures in piezoelectric energy harvesters, especially for mechanical energy harvesting from vibrations. In order to further lower the resonance frequency of the cantilever microstructure, a proof mass can be attached to the free end of the cantilever. Mechanical analysis of an experimental bimorph structure was provided and led to key design rules for post-processing steps to control the performance of the energy harvester. In this work, methods of materials processing and the mechanical to electrical conversion of vibrational energy into usable energy were investigated. Materials such as polyvinyledenedifluoridetetra-fluoroethylene P(VDF-TrFE) copolymer films (1um thick or less) were evaluated and presented a large relative permittivity and greater piezoelectric β-phase without stretching. Further investigations will be used to identify suitable micro-electromechanical systems (MEMs) structures given specific types of low-frequency mechanical excitations (10-100Hz).

2018 ◽  
Vol 29 (18) ◽  
pp. 3572-3581
Author(s):  
Suihan Liu ◽  
Ali Imani Azad ◽  
Rigoberto Burgueño

Piezoelectric energy harvesting from ambient vibrations is well studied, but harvesting from quasi-static responses is not yet fully explored. The lack of attention is because quasi-static actions are much slower than the resonance frequency of piezoelectric oscillators to achieve optimal outputs; however, they can be a common mechanical energy resource: from large civil structure deformations to biomechanical motions. The recent advances in bio-micro-electro-mechanical systems and wireless sensor technologies are motivating the study of piezoelectric energy harvesting from quasi-static conditions for low-power budget devices. This article presents a new approach of using quasi-static deformations to generate electrical power through an axially compressed bilaterally constrained strip with an attached piezoelectric layer. A theoretical model was developed to predict the strain distribution of the strip’s buckled configuration for calculating the electrical energy generation. Results from an experimental investigation and finite element simulations are in good agreement with the theoretical study. Test results from a prototyped device showed that a peak output power of 1.33 μW/cm2 was generated, which can adequately provide power supply for low-power budget devices. And a parametric study was also conducted to provide design guidance on selecting the dimensions of a device based on the external embedding structure.


Author(s):  
Shaofan Qi ◽  
Roger Shuttleworth ◽  
S. Olutunde Oyadiji

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.


Author(s):  
A. A. Mohamad Yusoff ◽  
K. A. Ahmad ◽  
S. N. Sulaiman ◽  
Z. Hussain ◽  
N. Abdullah

Introduction. Known vibrational energy harvesting methods use a source of vibration to harvest electric energy. Piezoelectric material works as a sensing element converted mechanical energy (vibration) to electrical energy (electric field). The existing piezoelectric energy harvesting (PEHs) devices have low sensitivity, low energy conversion, and low bandwidth. The novelty of the proposed work consists of the design of PEH’s structure. Air cavity was implemented in the design where it is located under the sensing membrane to improve sensitivity. Another novelty is also consisting in the design structure where the flexural membrane was located at the top of electrodes. The third novelty is a new design structure of printed circuit board (PCB). The purpose of improvised design is to increase the stress in between the edges of PEH and increase energy conversion. With the new structure of PCB, it will work as a substrate that absorbs surrounding vibration energy and transfers it to sensing element. Methods. Three techniques were successfully designed in PEH and fabricated namely PEH A, PEH B, and PEH C were characterized by two experiments: load and vibration. The load experiment measured load pressure towards the PEH, whereas the vibration experiment measured stress towards the PEH. Results. PEH C has the highest induced voltage for a weight of 5.2 kg at the frequency of 50 Hz and the highest stored voltage for a period of 4 min. The three techniques applied in PEHs were showed improvement in transducer sensitivity and energy conversion. Practical value. A piezoelectric acoustic generator was used in the experiment to compare the performance of the designed PEH with available piezoelectric transducers in the market. The new flexible membrane worked as a sensing element was worked as a cantilever beam. PVDF was used as a sensing element due to the flexibility of the polymer material, which is expected to improve sensitivity and operating bandwidth.


Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6759
Author(s):  
Ernesto A. Elvira-Hernández ◽  
Jorge Romero-García ◽  
Antonio Ledezma-Pérez ◽  
Agustín L. Herrera-May ◽  
Ernesto Hernández-Hernández ◽  
...  

Industry 4.0 and the Internet of Things have significantly increased the use of sensors and electronic products based on flexible substrates, which require electrical energy for their performance. This electrical energy can be supplied by piezoelectric vibrational energy harvesting (pVEH) devices. These devices can convert energy from ambient mechanical excitations into electrical energy. In order to develop, these devices require piezoelectric films fabricated with a simple and low-cost process. In this work, we synthesize ZnO nanorod film by a solvothermal method and deposit by spraying on ITO (indium-tin-oxide)/PET (polyethylene terephthalate) flexible substrate for a pVEH microdevice. The results of the characterization of the ZnO nanorod film using X-ray diffraction (XRD) confirm the typical reflections for this type of nanomaterial (JCPDS 36-145). Based on transmission electron microscopy (TEM) images, the size of the nanorod film is close to 1380 nm, and the average diameter is 221 ± 67 nm. In addition, the morphological characteristics of the ZnO nanorod film are obtained using atomic force microscopy (AFM) tapping images. The pVEH microdevice has a resonant frequency of 37 Hz, a generated voltage and electrical power of 9.12 V and 6.67 μW, respectively, considering a load resistance of 107.7 kΩ and acceleration of 1.5 g. The ZnO nanorod film may be applied to pVEH microdevices with flexible substrates using a low-cost and easy fabrication process.


2011 ◽  
Vol 22 (18) ◽  
pp. 2215-2228 ◽  
Author(s):  
Jayant Sirohi ◽  
Rohan Mahadik

There has been increasing interest in wireless sensor networks for a variety of outdoor applications including structural health monitoring and environmental monitoring. Replacement of batteries that power the nodes in these networks is maintenance intensive. A wind energy–harvesting device is proposed as an alternate power source for these wireless sensor nodes. The device is based on the galloping of a bar with triangular cross section attached to a cantilever beam. Piezoelectric sheets bonded to the beam convert the mechanical energy into electrical energy. A prototype device of size approximately 160 × 250 mm was fabricated and tested over a range of operating conditions in a wind tunnel, and the power dissipated across a load resistance was measured. A maximum power output of 53 mW was measured at a wind velocity of 11.6 mph. An analytical model incorporating the coupled electromechanical behavior of the piezoelectric sheets and quasi-steady aerodynamics was developed. The model showed good correlation with measurements, and it was concluded that a refined aerodynamic model may need to include apparent mass effects for more accurate predictions. The galloping piezoelectric energy-harvesting device has been shown to be a viable option for powering wireless sensor nodes in outdoor applications.


Aerospace ◽  
2006 ◽  
Author(s):  
R. M. Tieck ◽  
G. P. Carman ◽  
D. G. Enoch Lee

This paper presents a new approach using frequency rectification to harvest electrical energy from mechanical energy using piezoelectric devices. The rectification approach utilizes a linearly traveling Rectifier to impart vibrational motion to a cantilever piezoelectric bimorph. A conventional cantilever-type energy harvester is tested aside the rectified beam. The Standard beam generated 0.11 W of power, a power density of 15.63 kW/m3, and an energy density of 130.7 J/m3. The Rectified beam generated 580 mW of power, a power density of 871.92 kW/m3, and an energy density of 313.15 J/m3, a factor 2.4 greater than conventional energy harvesting methods. These results confirm the original thesis that a mechanically rectified piezoelectric Energy Harvester would generate larger Energy and Power Densities as well as Specific Powers, compared to conventional technologies.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2876
Author(s):  
Hailu Yang ◽  
Ya Wei ◽  
Weidong Zhang ◽  
Yibo Ai ◽  
Zhoujing Ye ◽  
...  

Road power generation technology is of significance for constructing smart roads. With a high electromechanical conversion rate and high bearing capacity, the stack piezoelectric transducer is one of the most used structures in road energy harvesting to convert mechanical energy into electrical energy. To further improve the energy generation efficiency of this type of piezoelectric energy harvester (PEH), this study theoretically and experimentally investigated the influences of connection mode, number of stack layers, ratio of height to cross-sectional area and number of units on the power generation performance. Two types of PEHs were designed and verified using a laboratory accelerated pavement testing system. The findings of this study can guide the structural optimization of PEHs to meet different purposes of sensing or energy harvesting.


2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Funda Demir ◽  
Mustafa Anutgan

The electrical energy production capability of bimorph (PbxX1-x)(ZryTizY1-y-z) fiber composite piezoelectric transducer has been investigated for energy harvesting applications. The material has been analyzed under different frequencies, bending amounts, and temperatures. The operating conditions for maximum electrical energy outcome have been determined. The natural frequencies of oscillations in the macro dimensions have been found to be inversely proportional to the length of the material. On the other hand, the voltage output with respect to the oscillation frequency exhibits an interesting behavior such that the characteristic curve shifts to higher frequencies as the bending radius is decreased. This behavior has been interpreted as a result of possible overtone transitions of the oscillations to a stiffer mode. The increasing temperature has been observed to have a negative effect on the piezoelectric energy harvesting property. When the determined optimum conditions were utilized, the amount of electrical energy stored in 6300 s by an energy harvester circuitry has been found to be 0.8 J.


2019 ◽  
Vol 11 (1) ◽  
pp. 168781401882014
Author(s):  
YiHe Zhang ◽  
Chul-Hee Lee

Energy generation technologies that use piezoelectric materials as uninterrupted power supplies are one of the most practical solutions of low-power wireless sensor network. The piezoelectric generator collects mechanical energy from the environment and transforms it into electricity to supply to microelectronic devices. Thus, these alternative energy sources can reduce the consumption of batteries, thereby reducing environmental pollution. Piezoelectric materials can work in the bending, compression, and shear modes, which are named as d31, d33, and d15 modes, respectively. In this study, a piezo stack which worked in d31 mode has been designed and integrated into an energy harvesting pedal. A novel compliant amplifying mechanism has to be designed to amplify the input load so that the high-stiffness piezoelectric stack can achieve a large energy output at a lower input force. This compliant mechanism has been designed by the pseudo-rigid-body and topology optimization methods. The amplification ratios of different sized flexible amplification mechanisms are calculated through the finite element analysis and validated by experiments. Finally, a pedal generator has been made and the test results show that the collected electricity can effectively drive a low-power microcontroller, sensor, and other devices of these kinds.


Piezoelectric elements are commonly installed in shoe sole to make use of the piezoelectric effect due to the vibration generated by the human motion. Piezoelectric shoe is a great device that can be used to harvest energy and can be improved by adding more piezoelectric elements and providing storage to store the harvested energy. However, not many researchers focus on the analyzation of piezoelectric elements’ shape that may affect the efficiency of energy harvesting. In this paper, piezoelectric energy harvesting shoes are designed with piezoelectric elements installed inside the soles of the shoes, thereby gaining mechanical energy from user while walking and running. The mechanical energy was applied to the piezoelectric elements and converted into electrical energy. Bridge rectifier was used to convert the AC voltage output into DC voltage. The project focused on analyzation of the efficiency between round and square shaped piezoelectric elements. Different shape of the piezoelectric element produced different amount of output voltage. Square shaped piezoelectric tended to produce lesser output voltage than the round piezoelectric element. A round piezoelectric with diameter of 4.5cm produced mean output voltage up to 11.56V and square piezoelectric with size of 4.5cm x 4.5cm produced 6.12V. However, this all depended on how much pressure that was applied onto the piezoelectric elements.


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