Enhanced poling efficiency via a maximized organic-inorganic interfacial effect for water droplet-driven energy harvesting

High‐performance piezoelectric yarns for artificial intelligence‐enabled wearable sensing and classification

“…On the other hand, the underlying mechanism for the enhanced piezoelectric properties of P(VDF‐TrFE) fibers incorporated with BTO nanoparticles can be delineated by electrostatic interactions within the composites. The attraction force between the hydroxyl groups formed on the BTO surfaces and negative fluorine atoms of P(VDF‐TrFE) can stabilize the all‐trans molecular conformation, as illustrated in Figure 1B, thereby facilitating the favorable nucleation of electroactive β‐phases 20–23 . However, excessive addition of BTO can be poisonous as BTO particle aggregates can cause polymer chains to break, which deteriorates the formation of β‐phases 21 .…”

“…The attraction force between the hydroxyl groups formed on the BTO surfaces and negative fluorine atoms of P(VDF-TrFE) can stabilize the all-trans molecular conformation, as illustrated in Figure 1B, thereby facilitating the favorable nucleation of electroactive β-phases. [20][21][22][23] However, excessive addition of BTO can be poisonous as BTO particle aggregates can cause polymer chains to break, which deteriorates the formation of β-phases. 21 Therefore, key to the piezoelectric fiber performance is tailoring the BTO doping level that can optimally maximize the formation of electroactive β-phases responsible for piezoelectricity.…”

“…Several approaches have been proposed to enhance the piezoelectric coefficient. On the one hand, the incorporation of nanofillers, such as silver nanowires, 13 salts, 14,15 ionic liquid surfactants, 16,17 MXenes, 18 and oxides, including zinc oxide (ZnO) 19 and barium titanate (BaTiO 3 , abbreviated as BTO in this study), [20][21][22][23] have been proven to efficiently promote the electroactive β-phase formation in poly(vinylidene fluoride) (PVDF) and its copolymers with tri-fluoroethylene (P(VDF-TrFE)), which are representative piezoelectric polymer materials. On the other hand, electrospinning is one of the technologically important fiber production techniques, which entails in situ mechanical stretching and poling, yielding self-poled electroactive crystalline β-phases in PVDF and P(VDF-TrFE) fibers.…”

High-performance piezoelectric nanogenerators featuring embedded organic nanodroplets for self-powered sensors

“…22 Among these crystalline phases in PVDF, the non-polarized α-phase without electroactive properties is the most stable and common, while the polar β-phase with the aligned polarization direction endows PVDF with the desired piezoelectric properties. 25–27 Accordingly, numerous methods including electric poling, 23,24 mechanical stretching 25,26 and melting crystallization with high pressure or high cooling rate have been proposed to maximize the content of polar β-phase in PVDF. 27–29 However, harsh conditions such as high temperature, high pressure, or high electric field are generally required for the fabrication of PVDF with a high β-phase content, which exhibits severe limitations in large-scale devices and practical applications.…”