Micro batteries about half the size of a human cell and built with viruses, may one day become a reality according to MIT researchers who have developed a way to create and install such microbatteries by stamping them onto a variety of surfaces.

From left, MIT professors Yet-Ming Chiang, Angela Belcher and Paula Hammond. The three have authored a paper detailing their virus-based method of creating and installing microbatteries by stamping them onto a variety of surfaces. Photo / Donna Coveney

In the Proceedings of the National Academy of Sciences (PNAS), the team described assembling and testing two of the three key components of a battery, the anode and the electrolyte. 

"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," said the research team, who were MIT professors Paula Hammond, Angela Belcher and Yet-Ming Chiang.

Significantly, the process "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.

The MIT team has created both the anode and the electrolyte, two of the key comments of a battery cell. A technique called soft lithography was used 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. Then viruses were used to form the anode on top the polymer layers on the posts. The virus's genes were altered so it makes protein coats that collect molecules of cobalt oxide to form ultrathin wires, creating the anode.

According to the team: "the resulting electrode arrays exhibit full electrochemical functionality."

The next step will be to create the cathode via the viral assembly technique. "We're also interested in integrating [the batteries] with biological organisms," said Belcher.