(15d) Self-Assembled Tri-Peptides As Water-Responsive Materials

Water-responsive (WR) materials that respond to relative humidity alternations by changing their shapes are receiving growing interest due to their potential applications, including the development of evaporation energy harvesting technique and WR artificial muscles. Materials with WR properties are widely observed in natural systems, such as pine cones, spider silk, and wheat awns. While WR mechanisms of these natural materials are still poorly understood, they share many common features, including hierarchical order, nanoscale pores, and ordered/disordered domains in their structures that are often composed of peptides and glycans. Inspired by nature, we crystalize short peptides into high performance WR materials. We demonstrate that these self-assembled short peptide crystals exhibit high WR strain (>25%), structural stability, mechanical stiffness (>2GPa), and high WR energy density (> 80kJ/m³).