In a surprise development that could have implications for powering electronics, cars and even the military, researchers at MIT have created the world’s first batteries constructed at the nano scale by microscopic viruses.
A much-buzzed-about paper published in the Proceedings of the National Academy of Sciences earlier this month details the team’s success in creating two of the three parts of a working battery—the positively charged anode and the electrolyte. But team leader Angela Belcher told PM Wednesday that the team has been seriously working on cathode technology for the past year, creating several complete prototypes.
“We haven’t published those yet, actually. We’re just getting ready to write them up and send them off,” says Belcher, who won a MacArthur genius grant for her work in 2004 and a Breakthrough Award from PM in 2006. “The cathode material has been a little more difficult, but we have several different candidates, and we have made full, working batteries.”
Instead of physically arranging the component parts, researchers genetically engineer viruses to attract individual molecules of materials they’re interested in, like cobalt oxide, from a solution, autonomously forming wires 17,000 times thinner than a sheet of paper that pack themselves together to form electrodes smaller than a human cell.
“Once you do the genetic engineering with the viruses themselves, you pour in the solution and they grow the right combination of these materials on them,” Belcher says.
The team is working on three main architectures: Filmlike structures—as small as a human cell—could form a clear film to power lab-on-a-chip applications to laminate into smart cards, or even to interface with implanted medical devices. Meshlike architectures—billions of tiny nano-components all interfaced together—might one day replace conventional batteries in larger applications such as laptops and cars. And fiberlike configurations—spun from liquid crystal like a spider’s silk—might one day be woven into textiles, providing a wearable power source for the military. “We definitely don’t have full batteries on those [fiber architectures]. We’ve only worked on single electrodes so far, but the idea is to try to make these fiber batteries that could be integrated into textiles and woven into lots of different shapes,” Belcher says.