CHISMACOMB - Honeycomb Structure Shows Its Strength

A Bristol University-led project has develped CHISMACOMB (CHIral SMArt honeyCOMB) material that can be embedded with sensors and eletromagnetic actuators to provide information about the structural integrity of sandwich structures used in civil, naval, aerospace, construction and electromagnetic shield applications.

The auxetic (amplifying) material uses an optimized chiral cellular core configuration – honeycomb-structured material – that also becomes thicker when stretched. It provides more flexibility without compromising its strength.

The material's unusual behavior can be explained by the scientific principle Negative Poisson's ratio – auxetic material stiffens when stretched in one direction. The auxetic behavior also leads to the material's bowl-shaped curve, which researchers say is useful when manufacturing curved sandwich shells.

Project leader Fabrizio Scarpa, of the aerospace engineering department at Bristol, began coordinating the honeycomb material when it matured in 2005 so it could work outside the lab. The result is a chiral structure that is suitable for manufacturing techniques such as rapid prototyping or possibley injection molding. The challenge for the future development of these structures is how to enhance the shapes of these materials to improve their structural integrity and to be proposed for multifunctional applications with sensing and actuating capabilities.