Enhanced strain gradient in structural wood for high flexoelectricity

), comparable to dielectric ceramics, and several times greater than semiconductors and polymers. The observed high flexoelectricity arises from the molecular-level charge asymmetry in cellulose's monoclinic crystalline structure, amplified by the anisotropic and hierarchical architecture of wood. Furthermore, we illustrate the practical potential by developing a flexible wood-based sensor capable of detecting subtle changes in human motion. This work provides a route to exploiting flexible wood for electromechanical applications.