Simple robots at Cornell University are being powered with a novel substance — one that, when heated, can expand more than 10 times in size, change viscosity by a factor of 10 and forcefully transition from regular to highly irregular granules. The substance is also inexpensive, readily available and biodegradable.
What could this remarkable substance be? Here’s a hint: You probably have some sitting around in your pantry at home.
And here’s the giveaway: The work is described in a paper called “Popcorn-Driven Robotic Actuators,” which examines how inexpensive robotic devices that grip, expand or change rigidity can be powered. With popcorn.
"The goal of our lab is to try to make very minimalistic robots which, when deployed in high numbers, can still accomplish great things," said Kirstin H. Petersen, an assistant professor of electrical and computer engineering who runs Cornell's Collective Embodied Intelligence Lab. "Simple robots are cheap and less prone to failures and wear, so we can have many operating autonomously over a long time. We are always looking for new and innovative ideas that will permit us to have more functionalities for less, and popcorn is one of those."
Indeed. When sufficient voltage is applied, popcorn kernels expand rapidly, exerting force and motion; this could allow bulky and expensive parts common to robotics, such as air pumps and compressors, to be eliminated.
There is a significant limitation, however: Generally speaking, a popcorn-powered mechanism could only be used once. But mechanical engineering doctoral student Steven Ceron notes that popped kernels can dissolve in water, making multiple uses within the realm of possibility.
Petersen’s hope is that the paper, which was presented recently at the IEEE International Conference on Robotics and Automation (ICRA 2018), will inspire researchers to explore the possibilities of other nontraditional materials. "In the end we come up with very simple solutions to fairly complex problems,” she said. “We don't always have to look for high-tech solutions. Sometimes the answer is right in front of us."