Popcorn-Driven Robotic Actuators was the title of a paper presented at the IEEE International Conference on Robotics and Automation in May of this year, IEEE Spectrum reports. The contents of the paper, written by a team from Cornell University, details how popcorn might be used to power robotic actuators in certain circumstances.
Since popcorn cannot be un-popped, an actuator powered by this technology would have to be disposed of after a single use. Thankfully, popcorn is biodegradable and cheap, so this could prove to be a viable option. The researchers envision popcorn-powered actuators being used for cheap and/or biodegradable robots performing a task in which they might need to deploy something, like a grabbing mechanism, only once.
You can see some of their test actuators in action in the video below and check out the full paper here.