"As electronic devices are made ever smaller, there is increasing demand for similarly minuscule power sources. Now MIT researchers have reported an important advance toward building such microscopic batteries. They used a virus to assemble anodes on top of electrolyte layers--two of the three main components of a working battery.
[Prof. Angela Belcher] adds that the cobalt oxide anode has a much higher charge storage capacity than the carbon-based electrodes typically used in lithium-ion batteries, and that it's stable throughout charging and discharging. It also has a higher density of active material than do conventional batteries.
Other advantages of virus assembly include functioning at room temperature and precise control over the size and spacing of nanomaterials, leading to uniform and easily reproducible devices."
The process involves etching micrometer-wide columns into silicon, laying down alternating layers of two polymers, then using the virus M13 to lay down "structured arrays of cobalt oxide nanowires" (previous described in Virus-Built Electronics) . The next step is to self-assemble cathodes, the remaining element of the battery.
The batteries could be used in "labs on a chip" or miniature medical devices.