NASA is looking to biological techniques that are millions of years old to help it develop new materials and technologies for the 21st century. Sponsored by NASA, Jeffrey Brinker of the University of New Mexico is studying how multiple elements can assemble themselves into a composite material that is clear, tough, and impermeable. His research is based on the model of how an abalone builds the nacre, also called mother-of-pearl, inside its shell. The mollusk layers bricks of calcium carbonate (the main ingredient in classroom chalk) and mortar of biopolymer to form a new material (top and bottom left) that is twice as hard and 1,000 times as tough as either of the original building materials.