MIT Team Use Viruses to Build Nex-Gen Batteries

If you think AAAs batteries are small, then consider this: Next-generation batteries may be half the size of a human cell and built with viruses. Now that’s small. MIT says this is the way of the future when it comes to powering tomorrow’s miniature electronic devices.

MIT engineers have developed a way to at once create and install such microbatteries. The team used a genetically modified (GM) virus to build a tiny microbattery that can power miniature electronic devices. The GM virus is called M13. The virus was designed to have negatively charged amino acids at its surface and an affinity with cobalt, a favored material for batteries. The research results have been described in the Proceedings of the National Academy of Sciences (PNAS).

“To our knowledge, this is the first instance in which microcontact printing has been used to fabricate and position microbattery electrodes and the first use of virus-based assembly in such a process,” wrote MIT professors Paula T. Hammond, Angela M. Belcher, Yet-Ming Chiang and colleagues.

Further, the technique itself “does not involve any expensive equipment, and is done at room temperature,” said Belcher, the Germeshausen Professor of Materials Science and Engineering and Biological Engineering.

Batteries consist of two opposite electrodes — an anode and cathode — separated by an electrolyte. In the current work, the MIT team created both the anode and the electrolyte.

So just how does a short-lived virus form an anode? Belcher explains that the viruses are just the “scaffolding”. Once they get the materials in place, they’re no longer needed.

“The virus just act as a matrix or scaffold to catalyze, grow and arrange materials, the virus are not active as a biological material,” Belcher explained to The Daily Galaxy. “The inorganic material is on top of the virus and has been shown be stable for over a year.”

First, on a clear, rubbery material the team used a common technique called soft lithography to create a pattern of tiny posts either four or eight millionths of a meter in diameter. On top of these posts, they then deposited several layers of two polymers that together act as the solid electrolyte and battery separator.

Next came viruses that preferentially self-assemble atop the polymer layers on the posts, ultimately forming the anode. Specifically, they altered the virus’s genes so it makes protein coats that collect molecules of cobalt oxide to form ultrathin wires.

The team concludes in their PNAS paper: “the resulting electrode arrays exhibit full electrochemical functionality.”

Belcher mentions, "We're also interested in integrating [the batteries] with biological organisms."

Bio-battery technology could open up a whole new field of science with exotic new applications. The study was partly funded by the Army Research Office Institute of Collaborative Biotechnologies, and the Army Research Office Institute of Soldier Nanotechnologies, which suggests that the Army has some interest in this type of research. One can only imagine the strange and/or nefarious possibilities of fusing batteries into living organisms. However, Belcher diffuses any excitement over possible cyborg applications.

“The Army is interested in small, safe light weight batteries,” Belcher explained to The Daily Galaxy.

As for Belcher and her colleagues, “We are thinking about integrating into medical devices that require power that would be biocompatible batteries.”

They still have to show that a microbattery can be successfully integrated with cells, but the current research looks promising. If you can successfully insert batteries into living cells, the list of future possibilities gets quite a bit longer and considerably more interesting.

Posted by Rebecca Sato

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*Portions of this post were adapted from an MIT news release