Alignment of Cellulose Nanocrystals by Solvent‐Assisted High‐Speed Electrospinning for Enhanced Piezoelectric Response

ABSTRACT Cellulose nanocrystals (CNCs) are a promising piezoelectric material due to their biodegradability and eco‐friendly characteristics, making them suitable for renewable electronic devices. However, random alignment of the dipoles in CNCs has been an obstacle to realizing their high piezoelectricity. Here, we developed a solvent‐assisted high‐speed electrospinning strategy for the alignment of the CNCs in cellulose acetate (CA) nanofiber matrix. The solvent in the mixed solution prevented molecular bonding between CNCs and CA, which allowed free rotation of the CNCs during high‐speed electrospinning. The large‐scale preferential alignment of the CNCs in the nanofiber significantly enhanced the piezoelectric performance of the composite film. The CNCs‐based nanogenerator exhibited an output voltage of 1.65 V under a repeated 1 N finger tapping. This strategy paved the way for applications of the CNCs in various electronic devices, which could also be extended to other bio‐piezoelectric materials.