Researchers at Cornell University have taken engineering inspired by nature to a whole new level.
In a newly published study in the Nature Journal, the researchers detail how they engineered a silicone fish-like robot with a circulation system powered by a liquid battery — or as they like to call it, ‘blood’. Their study’s name is: ‘Electrolytic vascular systems for energy-dense robots’.
Designing robots in this fashion helps engineers learn how soft, flexible robots perform in different environments. Robert Shepherd, an associate professor at Cornell’s Sibley School of Mechanical and Aerospace Engineering speaking to Popular Mechanics said, “I thought of this robot when I was at a workshop about avian-inspired aircraft.
“Some of the examples from biology included the Bar-tailed Godwit, which can fly for a week or more at a time without stopping.
“The blood in our bodies also performs multiple functions — delivering energy and removing waste, and it is simultaneously pumped by our heart and powers our hearts. The completion of this story arc was matching the blood concept with the mechanics of the hydraulically powered soft robots my lab makes.”
The engineers are experimenting with Redox Flow battery technology. These batteries are a type of electrochemical cell where energy is provided by two chemical components contained within the system that are dissolved in liquids and separated by a membrane. The engineers hope the robot can inspire other applications for soft-robots powered by the flow batteries.
The engineers managed to hydraulically pump the chemicals throughout the robot, maintaining its shape, but helping it move as well. The robot can run for 36 hours before needing to recharge, in part thanks to the battery fluid that not only acts as a hydraulic fluid but also energizes a pump that moves the fins, allowing the fish to ‘swim’.
The authors of the study are hoping that their findings in this fishy experiment eventually lead to reforms in modern robots and their energy storage systems. They write, “Modern robots lack the multifunctional interconnected systems found in living organisms and are consequently unable to reproduce their efficiency and autonomy.
“Energy-storage systems are among the most crucial limitations to robot autonomy, but their size, weight, material and design constraints can be re-examined in the context of multifunctional, bio-inspired applications.”
And so, the engineers worked to pack as much as they could into the thin 40-centimetre soft casing. The team has successfully cut down on the weight that other batteries would have added to their fish robot. They note in their journal that there are still some kinks to work out. However, if they can encourage the powering of robots in more flexible and lightweight sources, their contribution will be invaluable.
Hernandez, Daisy. “This Robotic Fish Is Powered by a 'Blood' Battery.” Popular Mechanics, Popular Mechanics, 21 June 2019, www.popularmechanics.com/science/a28120444/robotic-fish-blood-battery/.
Lu, Donna. “Robotic Fish Powered by Electronic Blood Can Swim for 36 Hours.” New Scientist, www.newscientist.com/article/2207175-robotic-fish-powered-by-electronic-blood-can-swim-for-36-hours/.