Researchers at Carnegie Mellon University have developed a 3D printing process that creates flat plastic items that fold into predetermined shapes when heated.
Known as Thermorph, the method relies on a natural phenomenon called ‘warpage’ that sometimes occurs when printing thermoplastic. Generally a nuisance, the Carnegie team has adopted warpage to its advantage. It used software algorithms developed in-house to precisely control an off-the-shelf FDM (fused deposition modelling) printer, combining the plastic with rubber-like materials and depositing them in such a way as to encourage warpage.
The objects emerge from the 3D printer as flat, hard plastic. When the plastic is placed in water hot enough to turn it soft— but not hot enough to melt it — the folding process is triggered.