Adaptive crystals could form basis for protective material

When stretched in a particular direction, the material becomes thicker in the perpendicular direction instead of getting thinner. Materials with this property are known as auxetic, and the behaviour is a result of the way the internal structure deforms when force is applied on one axis. Typically, the structures have high energy absorption and shatter resistance, making them useful in impact applications such as protective clothing, the soles of running shoes, and packing material.

According to the researchers, this is the first time an auxetic material has been created at the molecular level through design. To do so, they created a sheet-like crystal made of RhuA proteins connected in a regular, repeating tile pattern. Details of the work can be found online in the journal Nature.

“We found a way to create strong, flexible, reversible bonds to connect the protein tiles at their corners,” said research lead Akif Tezcan, a professor of chemistry and biochemistry at UC San Diego.