Enhanced magneto-mechano-electric conversion in flexible multiferroic nanocomposites via slender magnetic nanofibers regulated by tailored carbon nanotubes

Flexible multiferroic materials play a key role in self-powered wearable devices and wireless sensing systems, due to their ability for magneto-mechano-electric (MME) coupling response. Here, a flexible multiferroic film with a high MME voltage coefficient modulated by the slender 1-D magnetic nanomaterials is presented. To prepare the 1-D magnetic nanomaterials, carbon nanotube (CNT) is tailored into a slender template to induce the directional arrangement of CoFe2O4 (CFO) nanoparticles. The slender CNT-CFO can yield enhanced MME conversion in poly(vinylidene fluoride-trifluoroethylene)-based nanocomposites due to the synergism of CFO on a 1-D structure and enlarged interface areas between magnetic phase and piezoelectric matrix. Thus, a high MME coupling coefficient of 39.5 mV·cm−1·Oe-1 and mechano-electric output signals of 9.4 V are observed in nanocomposite films when the filler addition is less than 15 wt%. The low ratio of magnetic nanofibers is in favor of realizing the flexibility of polymer-based nanocomposites Moreover, the mechano-electric output signal with ∼ 1.4 times enhancement can be observed when a magnetic field is applied. The work is expected to open up new opportunities for flexible multiferroic nanocomposites in multifunctional devices and self-powered systems.