Efficient strain-mediated coupling in flexible magnetoelectric films enabled by CoFe2O4 nanofibers intrinsically anchored to P(VDF-TrFE)

The efficiency of strain-mediated magnetoelectric (ME) coupling is fundamentally governed by the fidelity of stress transfer across the interface between magnetostrictive and piezoelectric phases. In polymer-based nanocomposites, however, mechanical energy is often dissipated due to viscoelastic damping at interfaces, which severely limits the energy transduction efficiency. Herein, we fabricated flexible P(VDF-TrFE)-based ME nanocomposites through an intrinsically anchored strategy to enhance the interfacial stress transfer. By directing the growth of magnetic CoFe 2 O 4 on self-assembled s PPTA/BTAc aromatic backbones, we created intrinsically anchored magnetic nanofibers (IAM NFs) with skeleton-integrated nanostructure. In this geometric-chemical hybrid structure, molecular templates are interwoven with the magnetic phase, providing an aromatic backbone for direct stress conduction and abundant functional groups for molecular-level interlocking with polymer chains. Consequently, the composite achieves highly efficient strain-mediated ME coupling of 42.8 mV·cm −1 ·Oe −1 at an exceptionally low filler content of 1 wt%. By optimizing interfacial efficacy rather than increased filler content, the ME nanocomposite films maintain exceptional lightweight and flexibility, evidenced by breaking elongation of 23.3%. This work provides a strategic pathway for developing high-performance, lightweight, flexible electronics through rational interfacial engineering and morphological control.