Damping chitin hydrogels by harnessing insect-cuticle-inspired hierarchical structures

Nature builds complex and well-organized biomaterial structures from limited components that exhibit unparalleled mechanical properties. However, reproducing the mechanical properties of their natural counterparts, such as damping properties of insect cuticles, in a simple and universal biological material still remains a grand challenge. Here, we report a binary-solvent-induced self-assembly (BSISA) strategy to induce the self-assembly of chitin, a major component of insect cuticles, into hierarchically structured chitin hydrogels with a more than 100-fold increase in damping properties. These chitin hydrogels are proven to be well-organized hierarchical structures, similar to that observed in insect cuticles. Besides excellent toughness, fatigue resistance, biodegradability, and processability, these chitin hydrogels also exhibit electrifying damping properties (i.e., damping falling ball and protecting high-speed flying objects) over most synthetic soft materials and commercial engineering materials, making them high-performance alternatives to conventional biological materials used in broad application prospects including medical devices, robotics, soft-armor-like protection alternatives, etc.