Magnetic Nanorods Induced Construction of Multiresponsive Anisotropic Nanocellulose Films for Enhanced TENG Output

Inspired by the extraordinary functionality of biological systems that assemble anisotropic nanostructures, there is growing interest in designing multiscale ordered materials to modulate bio-based micro- and nanoscale assemblies for high performance and exceptional functionality. Current strategies for magnetic field-induced alignment of cellulose nanofibers face limitations, often relying on ultra-high magnetic fields or yielding poor orientation with microspherical magnetic particles. This study proposes an ordered assembly of cellulose nanofibers decorated with magnetic nanorods, induced under low magnetic fields. The resulting cellulose films exhibit an orientation parameter greater than 0.8. It demonstrates that the mechanism behind the magnetic field-induced alignment of magnetic nanorods with cellulose nanofibers results from a combination of magnetic torque-induced alignment of the rods and shear orientation driven by radial flow. This highly aligned, magnetically flexible, multiresponsive film achieves a dielectric constant elevated from 8.67 to 15.21. Simply by regulating the cellulose structure, the TENG output performance is improved to 971%. Compared with other complex modified cellulose film methods, the output performance is only enhanced to 760%. This method provides new insights into anisotropic assembly, with potential applications in flexible electronics and self-powered sensors.