"Rock Print," a sculptural installation currently on display at the Chicago Architecture Biennial, demonstrates a revolutionary concept: reversible concrete. Created by a team of researchers from MIT and ETH Zurich, the sculpture, made only of string and rocks, was built using 3D printing technology and the phenomenon known as "jamming." Read more at 3DPrint.com: http://3dprint.com/100088/3d-printed-rock-print/