If you want to build a bipedal robot than can do backflips, you're probably going to need traditional motors and batteries, but that's not where robots begin and end. We've seen dead simple robots powered by mere moisture and by lasers, but now there's an even more novel power source taking shape: .
The concept, spearhead by a team out of Cornell University led by , makes use of popcorn's characteristic ability to turn heat into mechanical force by its signature pop. Researchers found that certain kinds of popcorn kernels can increase to more than 15 times their original volume when popped, which allows them to function reasonably well as a single-use power source for cleverly designed robots. In , the researchers demonstrate three different bots: one that grips a ball when heated by a wire, one that lifts a weight when placed inside a microwave, and one that closes a mechanical claw when exposed to hot air:
Using popcorn for any of these purposes obviously has its downsides, the main one being that popcorn cannot be unpopped. But the upsides include its incredibly low price and its biodegradability, which could come in hand for robot designs that are intended to decompose after use.
Regardless of any immediately practical uses, the engineering behind this delicious new field of robotics is incredibly clever and a terrific step towards the ultimate goal of mechanical engineering: robots you can eat.