On the underside of the Red Abalone (Haliotis Rufescens) shell is a remarkable iridescent ceramic that is twice as tough as our high-tech ceramics. Mother-of-pearl, also called nacre, is composed of alternating layers of calcium carbonate (in a special crystal form called aragonite) and Lustrin-A protein. The combination of hard and elastic layers gives nacre remarkable toughness and strength, allowing the material to slide under compressive force. The “bricks” of calcium carbonate are offset, and this brick-wall architecture stops cracks from propagating. Several groups have mimicked nacre’s structure, using materials such as aluminum and titanium alloy to create a metal laminate tough enough for armor. 

Dr. Jeffrey Brinker’s group at Sandia National Laboratories used a self-assembly process to create mineral/polymer layered structures that are optically clear but much tougher than glass. Unlike traditional “heat, beat, and treat” technologies, Brinker’s evaporation-induced, low temperature process allows liquid building blocks to self-assemble and harden into very coatings that can toughen windshields, bodies of solar cars, airplanes or anything that needs to be lightweight but fracture-resistant. The complex nano-laminate structure of these bio-composite materials is characterized and related to their mechanical properties.

Researchers Nicholas Kotov and his colleagues at Oklahoma State University have developed a nanoscale, layered material that comes close to mother-of-pearl's (nacre's) properties such as strength and flexibility. The ability to nanomanufacture artificial nacre may provide lightweight, rigid composites for aircraft parts, artificial bone and other applications. They do this by alternating layers of clay and a type of polymer called a polyelectrolyte.

Product Overview: Lightweight Building Material
Inspired by: Abalone
Lead Researcher: Nicholas Kotov
Lab/University: Oklahoma State University
Availability: Under Development

Photograph courtesy of Alan Seaver