Equivalent capacitor of polyvinylidene fluoride sensor and its influence on impact load measurement

Piezoelectric PVDF sensors offer a unique option for the measurement of cavitation aggressiveness represented by the magnitude of impacts due to cavitation bubble collapses near walls. The aggressiveness measurement requires specific sensors shape and area, whereas commercial PVDF sensors are fabricated in limited geometry and size ranges. The photolithography method offers a possibility of production of home-made PVDF sensors of arbitrary shape and size. This paper deals with the calibration of a photolithographically home-made PVDF sensor for the cavitation impact load measurement. The calibration of sensors was carried out by the ball drop method. Sensors of different sizes were fabricated by the photolithography method from multi-purpose both side metallized PVDF sheet. The standard technology used for the fabrication of printed circuit boards was utilized. Commercial PVDF sensors of the same size were calibrated and the calibration results were compared with the home-made sensors. The effect of size and the effect of one added protective layer of Kapton tape on a sensor sensitivity were investigated.

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Design of distributed piezoelectric modal sensor for a rotating beam with elastic boundary restraints

Journal of Vibration and Control ◽

10.1177/1077546320923460 ◽

2020 ◽

Vol 26 (23-24) ◽

pp. 2340-2354

Author(s):

Jingtao Du ◽

Qi Chen

Keyword(s):

Boundary Conditions ◽

Polyvinylidene Fluoride ◽

Sensitivity Coefficient ◽

Sensor Design ◽

Rotating Beam ◽

Unified Framework ◽

Static Structure ◽

Rotating Beams ◽

Elastic Boundary ◽

Fluoride Sensor

As an advanced sensing technique, modal sensors have been attracting a lot of research interest in modal filtering and active control fields. Most of the existing investigations are mainly focused on the static structure. In contrast, there is little effort made for its rotating counterpart, which is frequently encountered in various power machineries. Motivated by such limitation, a unified framework for the distributed piezoelectric modal sensor design of rotating beams with elastic boundary restraints is proposed using polyvinylidene fluoride piezoelectric integral equation and the second-order structural modal functions. A boundary smoothed Fourier series is used to obtain the modal information of rotating beams by solving the differential governing equation and elastic boundary conditions, simultaneously. Modal sensor shape of rotating beams can be determined for any boundary condition by simply setting the elastic restraining coefficients accordingly, instead of reformulating the equation or rewriting the codes like other approach usually does. Numerical examples are presented to demonstrate the correctness and effectiveness of the proposed framework. Modal sensitivity coefficient and charge output frequency response under external excitation are calculated to demonstrate the performance of the designed piezoelectric modal sensors. Influence of rotation speed and boundary restraining stiffness on the modal sensing accuracy of the shaped polyvinylidene fluoride sensor is analyzed and addressed. To our best knowledge, this work represents the first time that an analytical solution for the distributed piezoelectric modal sensor design of a rotating beam with general boundary conditions is derived, which can shed some new lights on further design and implementation of polyvinylidene fluoride modal sensing technique for rotating structures.

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Research on Measurement of Transformer Short-circuit Force Using Piezoelectric Thin Film Polyvinylidene Fluoride Sensor

IEEE Transactions on Applied Superconductivity ◽

10.1109/tasc.2021.3096479 ◽

2021 ◽

pp. 1-1

Author(s):

Yan Li ◽

Tiannan Meng ◽

Bingbing Hou ◽

Xuejuan Zhang ◽

Yongteng Jing

Keyword(s):

Thin Film ◽

Polyvinylidene Fluoride ◽

Short Circuit ◽

Piezoelectric Thin Film ◽

Fluoride Sensor

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Impact Load Measurement by the Short Circuit Brake of the Wind-lens Turbine Blades

The Proceedings of Mechanical Engineering Congress Japan ◽

10.1299/jsmemecj.2016.j0310402 ◽

2016 ◽

Vol 2016 (0) ◽

pp. J0310402

Author(s):

Ryuta TSURUNAGA ◽

Satoru ODAHARA ◽

Wen-Xue WANG ◽

Takashi KARASUDANI

Keyword(s):

Impact Load ◽

Short Circuit ◽

Turbine Blades ◽

Load Measurement

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Force induced piezoelectric effect of polyvinylidene fluoride and polyvinylidene fluoride-co-trifluoroethylene nanofibrous scaffolds

The International Journal of Artificial Organs ◽

10.1177/0391398818785049 ◽

2018 ◽

Vol 41 (11) ◽

pp. 811-822 ◽

Cited By ~ 7

Author(s):

Fedaa Al Halabi ◽

Oleksandr Gryshkov ◽

Antonia I Kuhn ◽

Viktoria M Kapralova ◽

Birgit Glasmacher

Keyword(s):

Differential Scanning Calorimetry ◽

Fourier Transform ◽

Infrared Spectroscopy ◽

Fourier Transform Infrared Spectroscopy ◽

Polyvinylidene Fluoride ◽

Piezoelectric Effect ◽

Impact Load ◽

Piezoelectric Response ◽

Scanning Calorimetry ◽

Impact Forces

Polyvinylidene fluoride and its co-polymer with trifluoroethylene are promising biomaterials for supporting nerve regeneration processes because of their proven biocompatibility and piezoelectric properties that could stimulate cell ingrowth due to electrical activity upon mechanical deformation. This study reports the piezoelectric effect of electrospun polyvinylidene fluoride scaffolds in response to mechanical loading. An impact test machine was used to evaluate the generation of electrical voltage upon application of an impact load. Scaffolds were produced via electrospinning from polyvinylidene fluoride and polyvinylidene fluoride-co-trifluoroethylene with concentrations of 10–20 wt% dissolved in N,N-dimethylformamide (DMF) and acetone (6:4). The structural and thermal properties of scaffolds were analyzed using Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimetry, respectively. The piezoelectric response of the scaffolds was induced using a custom-made manual impact press machine. Impact forces between 0.4 and 14 N were applied. Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimetry results demonstrated the piezoelectric effect of the electrospun polyvinylidene fluoride and polyvinylidene fluoride-co-trifluoroethylene scaffolds. All the scaffolds exhibited a piezoelectric polar beta-phase formation. Their thermal enthalpies were higher than the value of the initial materials and exhibited a better tendency of crystallization. The electrospun scaffolds exhibited piezoelectric responses in form of voltage by applying impact load. Polyvinylidene fluoride-co-trifluoroethylene scaffolds showed higher values in the range of 6–30 V as compared to pure polyvinylidene fluoride. Here, the mechanically induced electrical impulses measured were between 2.5 and 8 V. Increasing the impact forces did not increase the piezoelectric effect. The results demonstrate the possibility of producing electrospun polyvinylidene fluoride and polyvinylidene fluoride-co-trifluoroethylene scaffolds as nerve guidance with piezoelectric response. Further experiments must be carried out to analyze the piezoelectricity at dynamic conditions.

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A damage identification method for a thin plate structure based on PVDF sensors and strain mode

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406219838579 ◽

2019 ◽

Vol 233 (14) ◽

pp. 4881-4895

Author(s):

Hongyu Cui ◽

Weiqiang Peng ◽

Xin Xu ◽

Ming Hong

Keyword(s):

Thin Plate ◽

Structural Damage ◽

Polyvinylidene Fluoride ◽

Damage Identification ◽

Damage Index ◽

Modal Identification ◽

Identification Methods ◽

Plate Structure ◽

Fluoride Sensor ◽

Structural Strain

Damage identification methods for engineering structures based on vibration parameters have the advantages of easy detection and high precision; however, structural strain information is more sensitive to structural damage than displacement information. Traditional resistance strain sensors have low accuracy and poor stability when measuring structural strains. Therefore, this paper uses a highly sensitive polyvinylidene fluoride dynamic strain sensor to identify structural damage in a thin plate. The polyvinylidene fluoride sensor is used to obtain structural strain response information, and structural modal parameters are identified using operational modal identification methods based on the natural excitation technique and the eigensystem realization algorithm. This paper uses a damage index based on mode shape and flexibility. A new damage index based on the LU decomposition of the flexibility matrix is used to identify the damage of the thin plate structure. The effectiveness of the modal identification methods and the new damage index is validated via an elastic thin plate experiment. The results show that the modal identification method and the new damage index proposed in this paper can identify damage in a thin plate structure. Sensor comparison experiments also show that compared with a resistance strain sensor, the polyvinylidene fluoride sensor has higher damage sensitivity, better damage recognition and the ability to recognize farther from the sensor.

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Experimental Study of Sidewall Pressure Induced by Ferroparticles in Fluid under a Pulsating Magnetic Field

Fluids ◽

10.3390/fluids5020098 ◽

2020 ◽

Vol 5 (2) ◽

pp. 98

Author(s):

Or Werner ◽

Asaf Azulay ◽

Boris Mikhailovich ◽

Avi Levy

Keyword(s):

Magnetic Field ◽

Carbonyl Iron ◽

Polyvinylidene Fluoride ◽

Particle Interaction ◽

Cardiac Pacing ◽

Field Exposure ◽

Water Chamber ◽

The Masses ◽

Fluoride Sensor ◽

The Magnetic Field

For several decades, magnetic nano- and microparticles have been used in various applications, as they can be attracted and controlled using external magnetic fields. Recently, carbonyl iron microparticles were used in a feasibility study of a new cardiac pacing application. The particles were inserted into a heart, attracted to its sidewall using a pulsating magnetic field, and applied pulsating pressure on its sidewall. The magnitude of the sidewall pressure is a critical parameter for the success and safety of the application, and it was evaluated analytically using a simplified model. In the present study, the behaviour of carbonyl iron microparticles in a water chamber was studied experimentally. Several masses of these particles were attracted to the sidewall of the chamber using an external pulsating magnetic field; the behaviours of the masses of particles, the particle–particle interaction, and the influence of fluid dynamics on them were examined during different periods of pulses. The sidewall pressure during their attraction was measured using an in-house piezoelectric polyvinylidene fluoride sensor. The relations between the measured sidewall pressure and the mass of the particles, their sizes, and the magnetic field exposure time were investigated. The obtained results suggest an asymptotic sidewall pressure value for the specified magnetic field. The measurements of the sidewall pressure are compared with evaluated results from the analytical model, showing that the model over-predicts the sidewall pressure.

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