Bio batteries provide food for thought

Biological batteries that mimic the human body's digestion process, converting food sources such as sugar and ethanol into energy, will be available for portable computers within five years, claim US scientists.

Biological batteries that mimic the human body's digestion process, converting food sources such as sugar and ethanol into energy, will be available for portable computers within five years, claim US scientists.

Nathan Lewis, professor of chemistry and chemical engineering at the University of California, who heads research into the technology, said that small ethanol-based fuel cells can be used to trickle power into a battery to prolong its life.

"There is 100 times the power density in a doughnut than in a computer battery," said Lewis, adding that the physical size and weight of the traditional rechargeable battery is the main barrier to making laptops truly portable.

Most commercial efforts to use fuel-cell technology have been directed towards alternative power sources for cars and electricity storage. But Lewis believes that the technology could be adapted.

"[Imagine] getting on a plane and ordering two little bottles of vodka: one for you and one for your computer," he said.