Robots and batteries: Don't you think one has already surpassed the other? Aside from the arising ethical dilemmas, there are some reasons why we are not experiencing a world that looks like a Terminator movie. And one reason for that is the fact that we can't power robots efficiently.
Batteries are decent sources of energy; however, the issue with them is that they are heavy and offer a limited supply. These obstacles form a solid obstacle to the development of robots in real-world environments.
At this point in history, we've reached the energy density limit that cannot be surpassed, which means that our batteries can't get any smaller than they already are without sacrificing much-needed energy.
One solution to overcome these obstacles is to harvest energy from the object's environment. Thanks to a group of brilliant researchers from the University of Pennsylvania's School of Engineering and Applied Science, a new technology could give robots the ability to generate energy by "eating" metal and "breathing" oxygen.
Are you getting the feel of robot cannibalism over there? We do, too. Interestingly, it paints a future where robots act more like biological beings.
10 times more power density than the best energy harvester
The team of researchers developed a metal-air scavenger (MAS) that works like a battery, by providing power through the breaking and forming a series of chemical bonds. However, it's also akin to a harvester since it supplies power through the energy in its surroundings, more specifically, through the chemical bonds in metal and air.
With this method, the power source has 10 times more power density than the best energy harvester and 13 times more energy density than lithium-ion batteries, researchers report.
How does it work?
The researchers developed a prototype of their metal harvester, and it rather looks like a thin film of Jello that you place onto a metal surface to extract energy from that metal. It's called a hydrogel, and it stores salty water in this particular case.
The hydrogel is also connected to a piece of carbon cloth that has tiny beads of platinum on it, the catalyst for the reduction of oxygen in the air. The ions pass in between these layers, thus resulting in electrons moving because they can't go through the electrolyte.
These move and go through, thereby powering the external device, in this case, a little robotic toy vehicle that is attached to the hydrogel film.
Demonstration of the self-powered toy car
The researchers demonstrated the technology by setting the same setup where the robotic car dragged the hydrogel along an aluminum surface. The self-powered toy car can be seen driving around in circles while carrying a small amount of water to regularly re-wet the hydrogel.
In this video, the researchers explain their project in-depth and clarity.
Metal as a biological concept: Food
James Pikul, assistant professor in the Department of Mechanical Engineering and Applied Mechanics, says. "As we get robots that are more intelligent and more capable, we no longer have to restrict ourselves to plug them into a wall. They can now find energy sources for themselves, just like humans do."
"One day, a robot that needs to recharge its batteries will just need to find some aluminum to 'eat' with a MAS, which would give it enough power to for it work until its next meal."
Thanks to this emerging technology, a robot might be able to recharge by consuming part of a metal surface whenever near one. According to the researchers, a small robot would need only the top of 100 micrometers of a metal object while a larger robot would presumably a bit more.
This is such a relief since dining out with robot friends would be rather awkward when you think about it. Staring while someone is rather rude after all, and now, at least, they can munch on "metal" and refuel with us out and about.
The research was published in the journal ACS Energy Letters.