Smart transparent protein biomaterial with tunable water-responsiveness properties

The preliminary focus of this research is to produce and characterize an active transparent silk material that can autonomously fold from a 2D film to a final 3D geometry while also abiding by biomedical engineering principles. Silk is a natural protein polymer consisting of amino acids that contribute to its higher hierarchical protein structures. The most common of these structures present are amorphous random coils that are more hydrophilic and stacked β-Sheet crystalline regions that are more hydrophobic. The transparent regenerated protein film is a water responsive (WR) material that can expand or contract in response to changes in relative humidity (RH). This was accomplished by tuning silks crystallinity by increasing the solutions degradation period. This research is highly valuable for self-folding materials such as soft robotics for biomedical and optical applications, and also contributes a framework constrained by sustainability and green engineering.