Nuclear batteries get smaller

Nuclear batteries have been safely powering devices such as satellites, Soviet lighthouses and underwater systems for years – but they are evolving to become even more useful. Let’s face it – most of us don’t own satellites or lighthouses.

The batteries already had an extremely long life and high energy density compared to chemical batteries. But they cost a few quid and are very large and heavy.

Now researchers at the University of Missouri are developing a nuclear battery that is lighter, more efficient and smaller – conveniently small. And of course they are capable of powering things for … well, longer than you are going to live.

Don’t get the wrong idea about the “nuclear battery”. It isn’t hazardous. Though it does generate electricity from atomic energy like nuclear reactors, it doesn’t use a chain reaction. It uses emissions from a radioactive isotope to generate electricity. So there’s no risk of the battery in your pace-maker giving you a coronary chernobyl.

How small? It is currently the size and thickness of a single penny, and is intended to power various micro and nanoelectromechanical systems. But the really cool bit it is that the innovation uses a liquid rather than solid semi-conductor.

Radioactive batteries, apart from giving out useful energy, also tend to damage the lattice structure of the solid semiconductor. By using a liquid semiconductor, the team thinks it has minimized the problem.

In the future, these egg-heads hope to increase the battery’s power, shrink its size – even to the width of a human hair – and try various other materials.