Popcorn-Powered Robots

Cornell University researchers have discovered how to power simple robots with popcorn – a novel substance that, when heated, can expand more than 10 times in size, change its viscosity by a factor of 10, and transition from regular to highly irregular granules with surprising force. After studying popcorn’s properties using different types of heating, the researchers constructed three simple robotic actuators. For a jamming actuator, 36 kernels of popcorn heated with nichrome wire were used to stiffen a flexible silicone beam. For an elastomer actuator, they constructed a three-fingered soft gripper, whose silicone fingers were stuffed with popcorn heated by nichrome wire. When the kernels popped, the expansion exerted pressure against the outer walls of the fingers, causing them to curl. For an origami actuator, they folded popcorn bags into origami folds, filled them with kernels, and microwaved them. The expansion of the kernels was strong enough to support a nine-pound kettlebell.