This work introduces a piezoelectric-pyroelectric nanogenerator (P-PNG) based on methylammonium lead iodide (CHNHPbI) incorporated electrospun poly(vinylidene fluoride) (PVDF) nanofibers that are able to harvest mechanical and thermal energies. During the application of a periodic compressive contact force at a frequency of 4 Hz, an output voltage of ∼220 mV is generated. The P-PNG has a piezoelectric coefficient () of ∼19.
View Article and Find Full Text PDFMethylammonium lead iodide (CHNHPbI) (MAPI)-embedded β-phase comprising porous poly(vinylidene fluoride) (PVDF) composite (MPC) films turns to an excellent material for energy harvester and photodetector (PD). MAPI enables to nucleate up to ∼91% of electroactive phase in PVDF to make it suitable for piezoelectric-based mechanical energy harvesters (PEHs), sensors, and actuators. The piezoelectric energy generation from PEH made with MPC film has been demonstrated under a simple human finger touch motion.
View Article and Find Full Text PDFFlexible and wearable piezoelectric bio e-skin (PBio-e-skin) based on electrospun poly(l-lactic acid) PLLA nanofiber membrane is demonstrated for non-invasive human physiological signal monitoring and detecting dynamic tactile stimuli. The molecular orientations of the C[double bond, length as m-dash]O dipoles by electrospinning technique result in a longitudinal piezoelectric charge co-efficient (d) value of ∼(3 ± 1) pm V realized by piezoresponse force microscopy, allowing the PBio-e-skin for pressure sensing applications. The robust mechanical strength (Young's modulus ∼50 MPa) of nanofiber membrane ensures PBio-e-skin's superior operational stability over 375 000 cycles.
View Article and Find Full Text PDFA remarkable improvement in the dielectric breakdown strength (Eb) and discharge energy density (U e) of flexible polymer nanocomposites is realized by the incorporation of unmodified smectite montmorillonite (MMT) nanoclay into a poly(vinylidene fluoride) (PVDF) matrix. The resulting PVDF/MMT clay nanocomposite (PCN) films stabilize the γ phase and increase the path tortuosity via strong intercalation of the PVDF matrix into inorganic layered silicates without sacrificing the quality of surface morphology. The PCN films exhibits superior dielectric properties (up to ε r ∼ 28 and tan δ ∼ 0.
View Article and Find Full Text PDFWe demonstrate the requirement of electrical poling can be avoided in flexible piezoelectric nanogenerators (FPNGs) made of low-temperature hydrothermally grown wurtzite zinc sulfide nanorods (ZnS-NRs) blended with polydimethylsiloxane (PDMS). It has been found that conductive fillers, such as polyaniline (PANI) and multiwall carbon nanotubes (MWCNTs), can subsequently improve the overall performance of FPNG. A large electrical throughput (open circuit voltage ∼35 V with power density ∼2.
View Article and Find Full Text PDFBiopolymers are expected to replace synthetic polymers in the quest for cost-effective, environment friendly, and pollution free technology. We report here a study on gelatin films with different concentrations of lithium perchlorate, which may be a candidate for electrolyte material in solid polymer batteries. Morphology studies and impedance spectroscopy both are done on the same set of samples.
View Article and Find Full Text PDFIn a pursuit of electronic level understanding of the antioxidant activity of a series of flavonoids, quantitative structure-activity relationship (QSAR) studies have been carried out using density functional theory (DFT) based quantum chemical descriptors. The best QSAR model have been selected for which the computed square correlation coefficient r(2) = 0.937 and cross-validated squared correlation coefficient q(2) =0.
View Article and Find Full Text PDFA model for diffusion on a cubic lattice with a random distribution of traps is developed. The traps are redistributed at certain time intervals. Such models are useful for describing systems showing dynamic disorder, such as ion-conducting polymers.
View Article and Find Full Text PDFPhys Rev B Condens Matter
August 1996
Phys Rev B Condens Matter
February 1992