Bioinspired stretchable molecular composites of 2D-layered materials and tandem repeat proteins
Abstract
Protein based composites, such as nacre and bone, show astounding evolutionary capabilities, including tunable physical properties. Inspired by natural composites, we studied assembly of atomistically thin inorganic sheets with genetically engineered polymeric proteins to achieve mechanically compliant and ultra-tough materials. Although bare inorganic nanosheets are brittle, we designed flexible composites with proteins, which are insensitive to flaws due to critical structural length scale (∼2 nm). These proteins, inspired by squid ring teeth, adhere to inorganic sheets via secondary structures (i.e., β-sheets and α-helices), which is essential for producing high stretchability (59 ± 1% fracture strain) and toughness (54.8 ± 2 MJ/m 3 ). We find that the mechanical properties can be optimized by adjusting the protein molecular weight and tandem repetition. These exceptional mechanical responses greatly exceed the current state-of-the-art stretchability for layered composites by over a factor of three, demonstrating the promise of engineering materials with reconfigurable physical properties.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 26, 2022
- Source ID
- 10.1073/pnas.2120021119
Entities
People
- Dong Li
- Huajian Gao
- Melik Demirel
- Mert Vural
- Oğuzhan Çolak
- Reginald F. Hamilton
- Tarek E Mazeed
Organizations
- Air Force Office of Scientific Research
- Army Research Office
- Brown University
- Nanyang Technological University
- Pennsylvania State University