Author: Getz Matthew
Date: October 2008
Most people who regard viruses as nothing more than disease causing pathogens would be surprised to learn of their newfound potential in electronics. A group of engineers at the Massachusetts Institute of Technology (MIT) recently discovered that viruses can help to assemble microbatteries that have the ability to power miniature electronic devices. The group published their work in the Proceedings of the National Academy of Sciences (PNAS) the week of August 18th, 2008.
Like most other batteries, these microbatteries, which are only a few micrometers in diameter, consist of an anode, a cathode, an electrolyte, and a separator. The anode and the cathode form the negative and positive poles of the battery respectively. The electrolyte allows the transfer of charge between the two poles. Finally, the separator keeps the anode and cathode apart.
The MIT group layered two polymers that would serve as the electrolyte and separator onto a 4µm-wide post. The group then encouraged the growth of genetically modified viruses that attract particles of metal on top of the layers. Specifically, the virus was altered to make protein coats that collect molecules of cobalt oxide to form ultrathin wires, which comprise the anode. The anode and electrolyte were then transferred to a platinum structure where, combined with lithium foil, the battery's functionality was tested. "The resulting electrode arrays exhibit full electrochemical functionality," claimed MIT professors Paula T. Hammond, Angela M. Belcher, Yet-Ming Chiang and colleagues in the PNAS paper.
"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 the group regarding its novel implementation of viruses in battery construction. The next step is to modify the viruses in order to produce the cathode and thus a fully functioning battery. According to Belcher, there is also interest "in integrating [the batteries] with biological organisms" in the future.
Written by Matt Getz
Edited by Hoi See Tsao
Published by Hoi See Tsao