Hitachi has unveiled plans for a revolutionary new personal digital assistant (PDA) that uses fuel cell technology.

The firm has produced a prototype PDA that can run off the energy source for around five hours.

The Hitachi PDA uses a direct methanol fuel cell which incorporates a platinum-ruthenium catalyst to convert the methonal fuel into hydrogen and carbon dioxide.

Hitachi says it plans to offer a more compact version of the PDA that can also offer longer usage before it considers it for commercial use.

After revisions to the prototype the firm hopes to launch sample shipments some time in 2005, a Hitachi official said.

The prototype PDA is the latest in a series of fuel cell-based consumer electronics products to be presented by Japanese electronics experts, with the development of an array of commercial applications of the technology seen as crucial in any long-term growth.