Magnetic 3-D-printed structures crawl, roll, jump, and play catch

Similar to marionettes without the strings, engineers at MIT have developed soft, 3-D-printed structures whose movements can be controlled with a magnet wave.The zoological garden of designs that can be attractively controlled incorporates a smooth ring that kinks up, a long cylinder that crushes shut, a sheet that folds itself, and an insect like “grabber” that can slither, roll, bounce, and snap together quickly enough to get a passing ball.

It can even be instructed to carry a small pill across a table by wrapping itself around it.Each structure was constructed by the researchers using a brand-new kind of 3-D-printable ink that they infused with microscopic magnetic particles.They attached an electromagnet to the nozzle of a 3-D printer, and as the ink passed through the nozzle, the magnetic particles shifted into a single orientation.

The researchers are able to produce structures and devices that can almost instantly shift into intricate formations and even move about as the various sections respond to an external magnetic field by controlling the magnetic orientation of individual sections in the structure.