Superflexible Wood.

Flexible porous membranes have attracted increasing scientific interest due to their wide applications in flexible electronics, energy storage devices, sensors, and bioscaffolds. Here, inspired by nature, we develop a facile and scalable top-down approach for fabricating a superflexible, biocompatible, biodegradable three-dimensional (3D) porous membrane directly from natural wood (coded as flexible wood membrane) via a one-step chemical treatment. The superflexibility is attributed to both physical and chemical changes of the natural wood, particularly formation of the wavy structure formed by simple delignification induced by partial removal of lignin/hemicellulose. The flexible wood membrane, which inherits its unique 3D porous structure with aligned cellulose nanofibers, biodegradability, and biocompatibility from natural wood, combined with the superflexibility imparted by a simple chemical treatment, holds great potential for a range of applications. As an example, we demonstrate the application of the flexible, breathable wood membrane as a 3D bioscaffold for cell growth.