Researchers have harnessed popcorn to drive simple robotic actuators. Cornell University engineers Steve Ceron, Kirstin H. Petersen, and colleagues demonstrated mechanical devices that exert force or change shape when their internal kernels pop. From Cornell:
The study is the first to consider powering robots with popcorn, which is inexpensive, readily available, biodegradable and of course, edible. Since kernels can expand rapidly, exerting force and motion when heated, they could potentially power miniature jumping robots. Edible devices could be ingested for medical procedures. The mix of hard, unpopped granules and lighter popped corn could replace fluids in soft robots without the need for air pumps or compressors.
"Pumps and compressors tend to be more expensive, and they add a lot of weight and expense to your robot," said Ceron, the paper's lead author. "With popcorn, in some of the demonstrations that we showed, you just need to apply voltage to get the kernels to pop, so it would take all the bulky and expensive parts out of the robots."
More in their scientific paper and at Smithsonian: "Popcorn-Powered Robots? Get 'Em While They're Hot!"