Lightweight carbon-fiber building blocks used to create strong structures

Science News : Carbon fiber is being used to create parts for bikes, cars, boats, and aircraft because of its strength and light weight. However, when carbon-fiber composites fail, the failure is distributed throughout the entire piece. So when a company approached Kenneth Cheung and Neil Gershenfeld of MIT to create an airplane from a single piece of carbon fiber, they decided to develop a small, repeatable carbon-fiber building block instead. The result is an X-shaped piece of carbon fiber with a hole in the center and loops at the end of each arm. The pieces are hooked together to create pyramidal lattices. When the 2-inch (5.08 cm) pieces were combined to create an 8-inch cube, the structure was able to support 295 kg (650 lbs) before breaking. And when it broke, only a few pieces failed, instead of the complete structure. To control where the points of failure occurred, Cheung and Gershenfeld included pieces that were more flexible in strategic positions in the structure. Their design could be used in any number of applications where weight-to-strength ratios are important.