Designing dielectric nanocomposite films with excellent dielectric properties is of strategic importance for a variety of applications requiring pressure sensing, energy harvesting and storing, and biomedical technology. Hence, the present investigation aims at studying the dielectric properties of lead lanthanum zirconate titanate (PLZT)/poly(vinylidene fluoride) (PVDF) nanocomposite based membranes fabricated using traditional electrospinning techniques. The composites were investigated for structural and electrical conductivity properties at varying temperatures. While the Scanning Electron microscope revealed beaded and unannealed micro/nanofibers, the observations of temperaturedependent electrical conductivity imply that the charge carrier transport phenomena involve more than one conduction mechanism. This is an interesting observation and can be explained in terms of the contents and porosity of the composites. As compared to PVDF, PLZT/PVDF nanocomposite films have somewhat better conductivity. The space charge limited current (SCLC) was the dominant mechanism at high voltages, while the Schottky-Richardson conduction mechanism was dominating at high temperature, according to observed J-V characteristics. The DC activation energy was found to be different, as expected, due to the dynamically heterogeneous nature of PLZT aggregates within the polymer matrix; however, the films exhibit the well-known Arrhenius relationship. This indicates that the dominant conduction mechanism is observed to be electronic and thermally activated.

Polyvinylidene fluoride (PVDF) is employed in a wide range of devices based on its excellent mechanical, optical, high thermal, piezoelectric, pyroelectric, and ferroelectric characteristics. In the current investigation, the pristine and neodymium oxide (Nd 2 O 3 ) nanoparticles embedded polyvinylidene fluoride (PVDF) thick films were prepared via solution casting method. The Nd 2 O 3 nanoparticles were synthesized via hydrothermal technique. The functional groups were identified in the nanocomposite films via infrared vibrational spectroscopy. It revealed the presence of ferroelectric β-phase in the annealed nanocomposite films. All-important optical constants have been determined for the first time via UV-VIS transmission spectroscopy for the nanocomposite films in the ferroelectric phase.

Piezoelectric energy conversion has received considerable attention for vibration-to-electric energy conversion over the past decade. A typical piezoelectric energy harvester is a unimorph or a bimorph cantilever located on a vibrating host structure. This paper presents a comparison between unimorph and bimorph cantilever beam having a number of segmented PMN-PT piezo-elements on the input and output power. The numerical simulation was carried out by applying the finite element analysis (FEA) using COMSOL multi-physics software in order to predict output voltage and power over a frequency range of 60–200 Hz for the first resonant frequencies. The simulation results show maximum output voltage and power harvested of 7.38 V and 135.73 μW, respectively, by the unimorph piezoelectric energy harvester at resonant frequency value of 84 Hz with electromechanical coupling factor (ke) of 77.29%. These results highlight that the highest value of the output electrical power can be obtained when the piezoelectric element is attached on the top of a clamped end of a cantilever piezoelectric beam. Moreover, in an unimorph or bimorph cantilever beam system, increasing the number of piezoelectric elements results in a higher resonant frequency shift and significantly decreasing in the harvested power.

No abstract