Bio-inspired protein creates stretchable 2D layered materials

By on July 26, 2022 0

UNIVERSITY PARK, PA – Nature creates layered materials like bone and mother-of-pearl that become less susceptible to flaws as they grow. Now, researchers have created, using biomimetic proteins modeled on squid ring teeth, 2D layered composite materials that are break-resistant and extremely stretchy.

“Researchers have rarely reported this interface property for bone and mother-of-pearl because it was difficult to measure experimentally,” said Melik Demirel, Lloyd and Dorothy Foehr Huck Professor of Biomimetic Materials and director of the Center for Advanced Fiber Technologies, Penn State.

2D composite materials are made up of atomic layers of a hard material, like graphene or an MXene, usually a transition metal carbide, nitride, or carbonitride, separated by layers of something to bond the layers together. While large chunks of graphene or MXenes have bulk properties, the strength of 2D composites comes from interfacial properties.

“Because we’re using an interface material that we can modify by repeating sequences, we can fine-tune the properties,” Demirel said. “We can make it very flexible and very strong at the same time.”

He noted that materials can also have unique heat conduction regimes or properties, radiating heat in one direction more strongly than 90 degrees. The results of this work have been published in the Proceedings of the National Academy of Sciences.

“This material would be ideal for running shoe insoles,” Demirel said. “It could cool the foot and repeated bending would not break the sole.”

These 2D composites could be used for flexible printed circuits, portable devices and other equipment requiring strength and flexibility.

According to Demirel, the traditional continuum theory does not explain why these materials are both strong and flexible, but the simulations have shown that the interface is important. What apparently happens is that with a higher percentage of material made up of the interface, the interface breaks in places when the material is stressed, but the material as a whole does not break.

“The interface breaks, but the material doesn’t,” Demirel said. “We expected them to become compliant, but all of a sudden it’s not just compliant, but super stretchy.”

Others working on this project in the form of Penn State were Mert Vural, postdoctoral fellow; Tarek Mazeed, postdoctoral fellow; Oguzhan Colak, graduate student; and Reginald F. Hamilton, associate professor of engineering science and mechanics.

Dong Li and Huajian Gao, professor of mechanical and aerospace engineering, both at Nanyang Technological University in Singapore, were also working on this research.

– This press release was originally posted on the Penn State website