The Massachusetts Institute of Technology develops a collection of objects that can accurately be described as magnetic shape-shifters. The entities are digitally produced and they range from a ring that changes its texture to a self-folding sheet. Perhaps the most impresive of the bunch is a spider-like creature that can "crawl, roll, jump and snap together quick enough to catch a passing ball."
In the development of these fun and innovative magnetic shape-shifters, the MIT engineers made use of specially developed 3D-printable ink that includes tiny magnetic particles. This is done by placing "an electromagnet around the nozzle of a 3D printer." As a result, when a magnet is waved in the vicinity, the objects respond adequately and "almost instantaneously."