Toshiba Corp. said Thursday it has developed a prototype of the world's smallest direct methanol fuel cell that can power hand-held devices such as digital audio players and wireless headsets for mobile phones.

The fuel cell is 56 mm long and 22 mm wide and weighs 8.5 grams, Toshiba said.

It has a power output of 100 milliwatts and is capable of powering an MP3 music player for 20 hours on a single 2 cc charge of concentrated methanol, Toshiba said.

Toshiba said it plans to commercialize the fuel cell by 2005.