Jayanth S | National Aerospace Laboratories (original) (raw)
Papers by Jayanth S
Piezoelectric polymer-ceramic composites are promising materials for transducer applications. PVD... more Piezoelectric polymer-ceramic composites are promising materials for transducer applications. PVDF-PZT composite films have been developed with different weight fraction and particle size of PZT using a solvent cast method. Films are investigated using X-ray diffraction technique, scanning electron microscopy, Fourier transformed infrared spectroscopy, and differential scanning calorimetry to study crystal structural changes, distribution of particles within the polymer matrix, the influence of these particles at the molecular level, and the changes induced in the melting transition and in the degree of crystallinity of the composites, respectively. The variation in these properties as a function of weight fraction (10–50%) and particle size (1 m and ∼25 m) of PZT has also been investigated. The composite films are tested for their application as acoustic emission (AE) sensor
Proceedings of SPIE, 2010
The β-phase of polyvinylidene fluoride (PVDF) is well known for its piezoelectric properties. PVD... more The β-phase of polyvinylidene fluoride (PVDF) is well known for its piezoelectric properties. PVDF films have been developed using solvent cast method. The films thus produced are in β-phase . The β-phase films are transformed to piezoelectric β-phase , when films are ...
Piezoelectric polymer PVDF poly (vinyledene fluoride) films play an important role in sensor and ... more Piezoelectric polymer PVDF poly (vinyledene fluoride) films play an important role in sensor and actuator applications. PVDF exists in four different phases, β, γ and , out of which β-phase is most suitable for piezoelectric applications. The present work concerns the development of -PVDF films, which are then converted to β-phase by appropriate thermo-mechanical treatment. The films are characterized for structural and surface morphological studies to investigate the presence of β-phase through X-ray diffraction, and scanning electron microscopy. These films are electroded and poled to align the dipoles and acquire piezoelectric properties. Being dielectric material, dielectric properties of PVDF has been studied in detail. As PVDF is flexible, light weight, chemically inert, tough and creep resistant, it has added advantages to put on curved surfaces. In the present study, various parameters of PVDF such as Permittivity, Tan, Capacity (pF), Impedance (Ω), Modulus, Conductivity...
Piezoelectric polymer-ceramic composites are promising materials for transducer applications. PVD... more Piezoelectric polymer-ceramic composites are promising materials for transducer applications. PVDF-PZT composite films have been developed with different weight fraction and particle size of PZT using a solvent cast method. Films are investigated using X-ray diffraction technique, scanning electron microscopy, Fourier transformed infrared spectroscopy, and differential scanning calorimetry to study crystal structural changes, distribution of particles within the polymer matrix, the influence of these particles at the molecular level, and the changes induced in the melting transition and in the degree of crystallinity of the composites, respectively. The variation in these properties as a function of weight fraction (10–50%) and particle size (1 m and ∼25 m) of PZT has also been investigated. The composite films are tested for their application as acoustic emission (AE) sensor
The beta-phase of polyvinylidene fluoride (PVDF) is well known for its piezoelectric properties. ... more The beta-phase of polyvinylidene fluoride (PVDF) is well
known for its piezoelectric properties. PVDF films have
been developed using solvent cast method. The films
thus produced are in alpha-phase. The alpha-phase is transformed to piezoelectric beta-phase when the film is hot stretched with various different stretching factors at
various different temperatures. The films are then characterized in terms of their mechanical properties and
surface morphological changes during the transformation
from alpha- to beta-phases by using X-ray diffraction, differential, scanning calorimeter, Raman spectra, Infrared
spectra, tensile testing, and scanning electron microscopy.
The films showed increased crystallinity with stretching at temperature up to 80C. The optimum conditions to achieve beta-phase have been discussed in detail. The fabricated PVDF sensors have been tested for free vibration and impact on plate structure, and its response is compared with conventional piezoelectric wafer type sensor. The resonant and antiresonant peaks in the frequency response of PVDF sensor match well with that of lead zirconate titanate wafer
sensors. Effective piezoelectric properties and the variations in the frequency response spectra due to free vibration and impact loading conditions are reported.
Piezoelectric polymer-ceramic composites are promising materials for transducer applications. PVD... more Piezoelectric polymer-ceramic composites are promising materials for transducer applications. PVDF-PZT composite films have been developed with different weight fraction and particle size of PZT using a solvent cast method. Films are investigated using X-ray diffraction technique, scanning electron microscopy, Fourier transformed infrared spectroscopy, and differential scanning calorimetry to study crystal structural changes, distribution of particles within the polymer matrix, the influence of these particles at the molecular level, and the changes induced in the melting transition and in the degree of crystallinity of the composites, respectively. The variation in these properties as a function of weight fraction (10–50%) and particle size (1 m and ∼25 m) of PZT has also been investigated. The composite films are tested for their application as acoustic emission (AE) sensor
Proceedings of SPIE, 2010
The β-phase of polyvinylidene fluoride (PVDF) is well known for its piezoelectric properties. PVD... more The β-phase of polyvinylidene fluoride (PVDF) is well known for its piezoelectric properties. PVDF films have been developed using solvent cast method. The films thus produced are in β-phase . The β-phase films are transformed to piezoelectric β-phase , when films are ...
Piezoelectric polymer PVDF poly (vinyledene fluoride) films play an important role in sensor and ... more Piezoelectric polymer PVDF poly (vinyledene fluoride) films play an important role in sensor and actuator applications. PVDF exists in four different phases, β, γ and , out of which β-phase is most suitable for piezoelectric applications. The present work concerns the development of -PVDF films, which are then converted to β-phase by appropriate thermo-mechanical treatment. The films are characterized for structural and surface morphological studies to investigate the presence of β-phase through X-ray diffraction, and scanning electron microscopy. These films are electroded and poled to align the dipoles and acquire piezoelectric properties. Being dielectric material, dielectric properties of PVDF has been studied in detail. As PVDF is flexible, light weight, chemically inert, tough and creep resistant, it has added advantages to put on curved surfaces. In the present study, various parameters of PVDF such as Permittivity, Tan, Capacity (pF), Impedance (Ω), Modulus, Conductivity...
Piezoelectric polymer-ceramic composites are promising materials for transducer applications. PVD... more Piezoelectric polymer-ceramic composites are promising materials for transducer applications. PVDF-PZT composite films have been developed with different weight fraction and particle size of PZT using a solvent cast method. Films are investigated using X-ray diffraction technique, scanning electron microscopy, Fourier transformed infrared spectroscopy, and differential scanning calorimetry to study crystal structural changes, distribution of particles within the polymer matrix, the influence of these particles at the molecular level, and the changes induced in the melting transition and in the degree of crystallinity of the composites, respectively. The variation in these properties as a function of weight fraction (10–50%) and particle size (1 m and ∼25 m) of PZT has also been investigated. The composite films are tested for their application as acoustic emission (AE) sensor
The beta-phase of polyvinylidene fluoride (PVDF) is well known for its piezoelectric properties. ... more The beta-phase of polyvinylidene fluoride (PVDF) is well
known for its piezoelectric properties. PVDF films have
been developed using solvent cast method. The films
thus produced are in alpha-phase. The alpha-phase is transformed to piezoelectric beta-phase when the film is hot stretched with various different stretching factors at
various different temperatures. The films are then characterized in terms of their mechanical properties and
surface morphological changes during the transformation
from alpha- to beta-phases by using X-ray diffraction, differential, scanning calorimeter, Raman spectra, Infrared
spectra, tensile testing, and scanning electron microscopy.
The films showed increased crystallinity with stretching at temperature up to 80C. The optimum conditions to achieve beta-phase have been discussed in detail. The fabricated PVDF sensors have been tested for free vibration and impact on plate structure, and its response is compared with conventional piezoelectric wafer type sensor. The resonant and antiresonant peaks in the frequency response of PVDF sensor match well with that of lead zirconate titanate wafer
sensors. Effective piezoelectric properties and the variations in the frequency response spectra due to free vibration and impact loading conditions are reported.