Handedness in shearing auxetics creates rigid and compliant structures

Jeffrey Ian Lipton, Robert MacCurdy, Zachary Manchester, Lillian Chin, Daniel Cellucci, Daniela Rus
2018 Science  
In nature, repeated base units produce handed structures that selectively bond to make rigid or compliant materials. Auxetic tilings are scale-independent frameworks made from repeated unit cells that expand under tension. We discovered how to produce handedness in auxetic unit cells that shear as they expand by changing the symmetries and alignments of auxetic tilings. Using the symmetry and alignment rules that we developed, we made handed shearing auxetics that tile planes, cylinders, and
more » ... eres. By compositing the handed shearing auxetics in a manner inspired by keratin and collagen, we produce both compliant structures that expand while twisting and deployable structures that can rigidly lock. This work opens up new possibilities in designing chemical frameworks, medical devices like stents, robotic systems, and deployable engineering structures.
doi:10.1126/science.aar4586 pmid:29748279 fatcat:wqnhrbtjb5e7tjsb4li54kaxiq