Magnetic, 3D-Printed, Moving Structures

Soft, 3D-printed structures have been created whose movements can be controlled with a wave of a magnet, much like marionettes without the strings. The structures that can be magnetically manipulated include a smooth ring that wrinkles up, a long tube that squeezes shut, a sheet that folds itself, and a spider-like “grabber” that can crawl, roll, jump, and snap together fast enough to catch a passing ball. It can even be directed to wrap itself around a small pill and carry it across a table.