Researchers at MIT have created a new form of 4D printing which enables them to create objects which have changing surface topographies. They do this by using a multi-material 3D printer and printing objects with various shapes of a harder, stiffer material within a more flexible material. When introduced to pressure the surface of the material changes. Such a process could be used in the manufacturing of camouflage, water repellents, and more. Additional information on this research can be found here: http://3dprint.com/72535/4d-printing-surface/


Below is a GIF simulating how one of these printed objects works: