Strain-enhanced stretchable molecular ferroelectric acoustic fibers

Molecular ferroelectrics—hybrid organic-inorganic architectures that exhibit piezoelectric coefficients comparable to classic oxide ceramics while offering rich compositional and structural tunability—have emerged as promising materials for human-interfaced high-frequency acoustic sensing. Nevertheless, the inherent brittleness and relatively high modulus hinder their practical deployment on dynamically deformable interfaces. Here, we report stretchable molecular ferroelectric acoustic fibers fabricated by incorporating molecular ferroelectric trimethylchloromethyl ammonium trichlorocadmium (TMCM-CdCl3) crystals into flexible thermoplastic polyurethane (TPU) via electrospinning. Intermolecular interactions between TMCM-CdCl3 and TPU, along with the interlocked layered architecture between electrodes and fibers, endow the fiber acoustic sensor with high stretchability (tensile strain >100%), high force sensing sensitivity (4.36 V/kPa), and wide-frequency acoustic sensing (30–5000 Hz). Crucially, a strain-induced sensitivity enhancement effect is proposed and verified, where…