Engineering highly electroactive nanofibers through high-speed spiral multidirectional drafting electrospinning for sensitive and stable motion monitoring textiles

The development of highly electroactive polymer fiber materials is essential for high-performance smart piezoelectric textiles. However, enhancing the piezoelectric properties of pure polymer fibers via a single force-field drafting process remains challenging. For instance, the reported piezoelectric phase (β-phase) content of poly(vinylidene fluoride) (PVDF) produced through electrostatic drafting remains below 93%. In this study, a high-speed spiral multidirectional drafting electrospinning strategy is proposed, which utilizes composite helical linear drafting during electric field polarization to significantly increase the β-phase content in pure polymer fibers. Using PVDF as an example, a record-high β-phase content of 97.63% has been achieved. The resulting flexible piezoelectric core-spun yarn exhibits a breaking tenacity of 43.02 cN/tex, fulfilling weaving strength requirements and ensuring robust sensor performance. The woven flexible sensor demonstrates a sensitivity of 0.035 V/N, approximately 45% higher than that of comparable fabric sensors reported previously. This enhanced performance makes it highly suitable for monitoring human joint movements and offers a promising solution for posture correction in athletes.