Innovative Origami Robot Folds Itself Up & Dissolves Into Nothing

Researchers from MIT demonstrated an untethered miniature origami robot that self-folds, walks, swims, and degrades. From a flat sheet with a magnet on it, this robot folds itself up in seconds, is immediately ready to zip around on land or water driven by magnetic fields. Once done, it is capable of self-dissolving in a tank of acetone. The innovative technology is expected to have myriad applications for use in vivo. 

Never before has a robot has been able to demonstrate a complete life cycle like this, and this major innovation was a big hit at ICRA 2015 in Seattle as seen in these highlights.

“We complete the cycle from birth through life, activity, and the end of life,” first author Shuhei Miyashita says. “The circle is closed.”

Weighing only a third of a gram, the robot can swim, climb an incline, traverse rough terrain, and carry a load twice its weight. Other than the self-folding plastic sheet, the robot’s only component is a permanent magnet affixed to its back. Its motions are controlled by external magnetic fields. See how it works.

The origami robot and the actuation methods. (a) Outlook of the system. (b) The crease pattern. (c) Walking mode by torque-based control. (d) Swimming mode by force-based control.

The unfolded robot, which is made of a magnet and PVC sandwiched between laser-cut structural layers (polystyrene or paper), weighs just 0.31 g and measures 1.7 cm on a side. Once placed on a heating element, the PVC contracts, and where the structural layers have been cut, it creates folds.

“The entire walking motion is embedded into the mechanics of the robot body,” says Cynthia R. Sung, an MIT graduate student in electrical engineering and computer science and one of the robot’s co-developers. “In previous [origami] robots, they had to design electronics and motors to actuate the body itself.”

The robot’s design was motivated by a hypothetical application in which tiny sheets of material would be injected into the human body, navigate to an intervention site, fold themselves up, and, when they had finished their assigned tasks, dissolve. To that end, the researchers built their prototypes from liquid-soluble materials. One prototype robot dissolved almost entirely in acetone (the permanent magnet remained); another had components that were soluble in water.