Investigation of MEMS Piezoelectric Transformer with PVDF Thin Layer

2016 ◽  
Vol 856 ◽  
pp. 356-361
Author(s):  
Yordanka Dilyanova Vucheva ◽  
Georgi Dobrev Kolev ◽  
Mariya Petrova Aleksandrova ◽  
Krassimir Hristov Denishev
Keyword(s):  
Transfer Function ◽  
Polyvinylidene Fluoride ◽  
Spray Deposition ◽  
Low Frequency ◽  
Pvdf Film ◽  
Stable Operation ◽  
Dielectric Losses ◽  
Piezoelectric Transformer ◽  
Boundary Frequency ◽  
High Dielectric

This paper presents the results of experimental work on thin piezoelectric polyvinylidene fluoride (PVDF) film, used as active layer in piezoelectric transformer. PVDF film was deposited by spray deposition technique on flexible polyethylene terephthalate (PET) substrate and its thickness was measured to be 2 μm. Aluminum (Al) bottom and top contacts were deposited by vacuum thermal evaporation. The transfer function of the transformer was measured at different frequencies in the range 50 Hz – 4 MHz. It was observed that at input frequency of 1 MHz, the transfer function started to decrease, which supposed low-frequency AC/AC transformer. Dielectric losses, which characterize piezoelectric devices’ quality, were less that 0.09 in the whole frequency range. This is proof for the efficient energy conversion and stable operation of the microstructure. The work shows that the PVDF transformer performance is comparable to the existing piezoceramic based transformers, which however suffer of high dielectric losses, signal distortions and relatively low boundary frequency.

Dielectric and Energy Storage Properties of Polyvinylidene Fluoride/Barium Titanate Nanocomposites

2013 ◽  
Vol 833 ◽  
pp. 365-369 ◽  
Author(s):  
Yan Xia Li ◽  
Jin Long Xie ◽  
Zhen Ming Chu ◽  
Xu Sheng Wang ◽  
Xi Yao
Keyword(s):  
Energy Storage ◽  
Barium Titanate ◽  
Polyvinylidene Fluoride ◽  
Breakdown Strength ◽  
Pvdf Film ◽  
Dielectric Performance ◽  
Energy Storage Properties ◽  
High Dielectric ◽  
Pure Pvdf ◽  
Storage Properties

The combination of nanoparticles with high relative permittivity and polymers with high dielectric strength offers a potential to obtain processable nanocomposites with high dielectric performance. In this work, polyvinylidene fluoride (PVDF)-barium titanate (BT) nanocomposites were prepared by spin-coating technique. The surface of BT nanoparticles was treated by titanate coupling agent NDZ101. The dielectric and energy storage properties of the system were studied as a function of BT content. The experimental results showed that the dielectric constant of the nanocomposites increased with the increase of BT content. Although pure PVDF material has the strongest dielectric breakdown strength, the discharged energy storage density Ue of the nanocomposites was greatly improved from 2.8 J/cm3 in pure PVDF film to 6.2 J/cm3 in PVDF/20 wt% BT film; due to larger polarization of the nanocomposite.

scholarly journals Dielectric and Structural Properties of Poly(vinylidene fluoride) (PVDF) and Poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) Filled with Magnesium Oxide Nanofillers

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
A. N. Arshad ◽  
M. H. M. Wahid ◽  
M. Rusop ◽  
W. H. A. Majid ◽  
R. H. Y. Subban ◽  
...  
Keyword(s):  
Magnesium Oxide ◽  
Vinylidene Fluoride ◽  
Low Frequency ◽  
Film Surface ◽  
Weight Percent ◽  
Pvdf Film ◽  
Low Dielectric ◽  
Metal Insulator Metal ◽  
Poly Vinylidene Fluoride ◽  
High Dielectric

This study examines the dielectric properties of filled PVDF film and filled PVDF-TrFE film incorporated with 1, 3, 5, and 7 weight percentages of magnesium oxide (MgO) nanofillers. The metal-insulator-metal (MIM) configuration demonstrates PVDF/MgO with 7 weight percent of MgO which produced high dielectric constant (1 kHz) with low dielectric loss. The ATR-FTIR spectra of PVDF/MgO (7%) indicate wide bonding peaks at 840 cm-1 and 880 cm-1, assigned to -CH2 and -CF2 groups, respectively. This implies the presence of high content of β-crystals in the PVDF/MgO (7%) film. A shift in the peak was observed in the same film, from 1170 cm-1 to 1180 cm-1 suggesting possible transformation from γ-crystals to β-crystals. This film showed no apparent defect on its film surface. Thus, it established that PVDF incorporated with 7% MgO can be used to produce nanocomposite thin film for low-frequency electronic devices.

scholarly journals Generating Electricity from Natural Evaporation Using PVDF Thin Films Incorporating Nanocomposite Materials

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 585
Author(s):  
Ariel Ma ◽  
Jian Yu ◽  
William Uspal
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Polyvinylidene Fluoride ◽  
Capillary Flow ◽  
Short Circuit ◽  
Current Source ◽  
Nanocomposite Materials ◽  
The Other ◽  
Pvdf Film ◽  
Ambient Conditions

Natural evaporation has recently come under consideration as a viable source of renewable energy. Demonstrations of the validity of the concept have been reported for devices incorporating carbon-based nanocomposite materials. In this study, we investigated the possibility of using polymer thin films to generate electricity from natural evaporation. We considered a polymeric system based on polyvinylidene fluoride (PVDF). Porous PVDF films were created by incorporating a variety of nanocomposite materials into the polymer structure through a simple mixing procedure. Three nanocomposite materials were considered: carbon nanotubes, graphene oxide, and silica. The evaporation-induced electricity generation was confirmed experimentally under various ambient conditions. Among the nanocomposite materials considered, mesoporous silica (SBA-15) was found to outperform the other two materials in terms of open-circuit voltage, and graphene oxide generated the highest short-circuit current. It was found that the nanocomposite material content in the PVDF film plays an important role: on the one hand, if particles are too few in number, the number of channels will be insufficient to support a strong capillary flow; on the other hand, an excessive number of particles will suppress the flow due to excessive water absorption underneath the surface. We show that the device can be modeled as a simple circuit powered by a current source with excellent agreement between the theoretical predictions and experimental data.

Dynamic Stability of a Water Brake Dynamometer

1998 ◽  
Vol 120 (1) ◽  
pp. 89-96 ◽  
Author(s):  
R. A. Van den Braembussche ◽  
H. Malys
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Lumped Parameter Model ◽  
Stable Operation ◽  
Pressure Oscillations ◽  
Lumped Parameter ◽  
Flow Oscillations ◽  
Brake Dynamometer ◽  
Low Torque ◽  
Frequency Variations

A lumped parameter model to predict the high frequency pressure oscillations observed in a water brake dynamometer is presented. It explains how the measured low frequency variations of the torque are a consequence of the variation in amplitude of the high frequency flow oscillations. Based on this model, geometrical modifications were defined, aiming to suppress the oscillations while maintaining mechanical integrity of the device. An experimental verification demonstrated the validity of the model and showed a very stable operation of the modified dynamometer even at very low torque.

Liquid encapsulated electrostatic energy harvester for low-frequency vibrations

2012 ◽  
Vol 24 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Ling Bu ◽  
Xiaoming Wu ◽  
Xiaohong Wang ◽  
Litian Liu
Keyword(s):  
Polyvinylidene Fluoride ◽  
Output Voltage ◽  
Energy Harvester ◽  
Low Frequency ◽  
Electrostatic Energy ◽  
Maximum Output ◽  
Flowing Liquid ◽  
Horizontal Vibration ◽  
Low Viscosity ◽  
High Relative Permittivity

This article presents the modeling, fabrication, and testing of liquid encapsulated energy harvester using polyvinylidene fluoride electrets. Unlike harvesters reported in previous literature, this liquid encapsulated energy harvester uses flowing liquid rather than conventional resonating structures to induce variable capacitance and is more suitable for low-frequency applications. Prototypes injected with three types of liquid ( N-methyl-2-pyrrolidone, N, N-dimethylformamide, and glycerin) are tested in horizontal vibration and rotary motion mode, respectively. The results show that N, N-dimethylformamide–injected prototypes display the most desirable performance in horizontal vibration testing at 1–10 Hz due to high relative permittivity and low viscosity, with maximum output voltage of 2.32 V and power of 0.18 µW at 10 Hz. Glycerin-injected prototypes perform best at 0.1–1 Hz rotation due to effective movement and highest permittivity, with maximum output voltage of 11.46 V and power of 2.19 µW at 1 Hz.

Prediction of Surge Motion Response of Floating Structure Using Kalman Smoother Adaptive Filters Based Time-Domain Volterra Model

2014 ◽  
Vol 660 ◽  
pp. 799-803
Author(s):  
Edwar Yazid ◽  
M.S. Liew ◽  
Setyamartana Parman ◽  
V.J. Kurian ◽  
C.Y. Ng
Keyword(s):  
Time Series ◽  
Transfer Function ◽  
Time Domain ◽  
Adaptive Filters ◽  
Low Frequency ◽  
Volterra Model ◽  
Floating Structure ◽  
Frequency Responses ◽  
Kalman Smoother ◽  
System Output

This work presents an approachto predict the low frequency and wave frequency responses (LFR and WFR) of afloating structure using Kalman smoother adaptive filters based time domain Volterramodel. This method utilized time series of a measured wave height as systeminput and surge motion as system output and used to generate the linear andnonlinear transfer function (TFs). Based on those TFs, predictions of surgemotion in terms of LFR and WFR were carried out in certain frequency ranges ofwave heights. The applicability of the proposed method is then applied in ascaled 1:100 model of a semisubmersible prototype.

Research on PVDF Micro-Force Sensor

2014 ◽  
Vol 599-601 ◽  
pp. 1135-1138
Author(s):  
Chao Zhe Ma ◽  
Jin Song Du ◽  
Yi Yang Liu
Keyword(s):  
Power Dissipation ◽  
Polyvinylidene Fluoride ◽  
High Sensitivity ◽  
Force Sensor ◽  
Calibration Method ◽  
Pvdf Film ◽  
Force Sensors ◽  
Low Power Dissipation ◽  
Micro Force Sensor ◽  
Processing Circuit

At present, sub-micro-Newton (sub-μN) micro-force in micro-assembly and micro-manipulation is not able to be measured reliably. The piezoelectric micro-force sensors offer a lot of advantages for MEMS applications such as low power dissipation, high sensitivity, and easily integrated with piezoelectric micro-actuators. In spite of many advantages above, the research efforts are relatively limited compared to piezoresistive micro-force sensors. In this paper, Sensitive component is polyvinylidene fluoride (PVDF) and the research object is micro-force sensor based on PVDF film. Moreover, the model of micro-force and sensor’s output voltage is built up, signal processing circuit is designed, and a novel calibration method of micro-force sensor is designed to reliably measure force in the range of sub-μN. The experimental results show the PVDF sensor is designed in this paper with sub-μN resolution.

ELECTROMECHANICAL CHARACTERISTICS OF POLYVINYLIDENE FLUORIDE FOR FLEXIBLE ELECTRONICS

2013 ◽  
Vol 37 (3) ◽  
pp. 325-333 ◽  
Author(s):  
Wen-Yang Chang ◽  
Cheng-Hung Hsu
Keyword(s):  
Flexible Electronics ◽  
Polyvinylidene Fluoride ◽  
Input Voltage ◽  
Pvdf Film ◽  
Resistive Load ◽  
X Ray Diffraction ◽  
Leakage Currents ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Stress Cycles

The electromechanical characteristics of PVDF are investigated, including the crystallization, frequency responses, hysteresis, leakage currents, current-voltage characteristics, and fatigue characteristics using X-ray diffraction and an electrometer. Results show that the frequency band of PVDF increases with increasing resistive load and capacitance. The hysteresis area of ΔH slightly increases with increasing input voltage. The magnitude of the current values increases with decreasing delay time at a given drive voltage. PVDF film induced larger degradation when the number of stress cycles was increased to about 105 cumulative cycles.

A Dynamic Calibration Test on PVDF Film Pressure Sensor with Dropping Hammer Method

2014 ◽  
Vol 933 ◽  
pp. 548-553 ◽  
Author(s):  
Yong Qiang Wang ◽  
Ying Lin Xiao
Keyword(s):  
Polyvinylidene Fluoride ◽  
Piezoelectric Materials ◽  
Dynamic Pressure ◽  
High Sensitivity ◽  
Pvdf Film ◽  
Piezoelectric Film ◽  
High Mechanical Strength ◽  
Response Range ◽  
New Type ◽  
Shock Wave Pressure

Polyvinylidene Fluoride (referred to as PVDF) piezoelectric film is a new type of polymer piezoelectric materials. Because of its light weight, thin thickness, high sensitivity, high mechanical strength, wide frequency response range and other advantages, it has the application prospect in the explosion field. In this article, film sensors were made based on the PVDF piezoelectric film, and its role in the sensors is the sensitive element. The result of the low dynamic pressure calibration tests showed that it has a very high linear degree and good reproducibility, so that it can be used for low-pressure section of the shock wave pressure measurement.

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