Viruses Can be Used as Battery

Professors Yet-Ming Chiang, Angela Belcher and Paula Hammond from MIT proudly stand with a battery-building virus they have engineered. The virus is on a glass slide held by Belcher, center.

Donna Coveney, MIT

 In Cambridge, Massachusetts, scientists have discovered that some viruses can be helpful in an unusual way. They are putting viruses to work, teaching them to build some of the world’s smallest rechargeable batteries.

Viruses and batteries may seem like an unusual pair, but they’re not so strange for engineer Angela Belcher, who first came up with the idea. At the Massachusetts Institute of Technology (MIT) in Cambridge, she and her collaborators bring together different areas of science in new ways. In the case of the virus-built batteries, the scientists combine what they know about biology (the study of living things), technology and production techniques.

Many batteries are already pretty small. You can hold A, C and D batteries in your hand and the coin-like batteries that power watches are often smaller than a penny. However, every year, new electronic devices like personal music players or cell phones get smaller than the year before. As these devices shrink, ordinary batteries won’t be small enough to fit inside.

The ideal battery will store a lot of energy in a small package. Right now, Belcher’s model battery, a metallic disk completely built by viruses, looks like a regular watch battery. But inside, its components are very small—so tiny you can only see them with a powerful microscope.

How small are these battery parts? To get some idea of the size, pluck one hair from your head (unless that seems too painful). Place your hair on a piece of white paper and try to see how wide your hair is—pretty thin, right? Although the width of each person’s hair is a bit different, you could probably fit about 10 of these virus-built battery parts, side to side, across one hair. These microbatteries (“micro” means very small) may change the way we look at viruses.

The battery — the silver-colored disk on the right side of the device — is being used to power an LED.