Bi-filler Interacted β-Phase Enhancement in Polyvinylidene Fluoride Composited with Cellulose Nanocrystals and Nickel Ferrite: A Multifunctional Energy Harvester and Sleep Monitoring Sensor
Résumé
This work presents the fabrication of a composite fiber comprising cellulose nanocrystals (CNCs) and magnetic nickel ferrite (NFO) integrated with poly(vinylidene fluoride) (PVDF) for multifunctional energy harvesting (EH) from both mechanical vibrations and stray magnetic fields. The addition of NFO and CNCs enhances the electroactive phase within PVDF, resulting in bi-filler electrostatic interactions between NFO and CNCs. The fabricated EH system is capable of generating a significant magnetoelectric voltage, achieving 20 mV/cm even in the presence of a weak magnetic field of 4 Oe, for both PNFO (PVDF/NFO) and PCNNF (PVDF/CNC/NFO) composites, respectively. PCNNF exhibits superior piezoelectric energy harvesting performance, with a higher peak-to-peak output voltage (Vp-p) of 14.68 V, along with a power density and current density of 49.25 μW/cm3 and 14.71 μA/cm3, respectively, when tested under a load resistance of 6.2 MΩ at a frequency of 5 Hz and an applied force of 8 N. Finally, a sleep monitoring application was demonstrated using the fabricated PENG device potentially applicable in healthcare.