Toshiba has announced that its fuel cell has been officially certified by the Guinness World Records as the smallest of its kind.

The direct methanol fuel cell measures just 2.2cm by 5.6cm and is 0.45cm thick.

However the fuel cell is remarkably potent, boasting a power output of 100 milliwatts.

The company says it is capable of operating an MP3 portable digital music player for a maximum of 20 hours with a single 2cc charge of highly concentrated methanol.

"We are really honoured and delighted that an organization as respected as Guinness World Records has certified our fuel cell as the world's smallest direct methanol fuel cell," said Kazunori Fukuma, managing director of Toshiba's display devices and components control centre.

"This is a welcome recognition of our efforts to stay a step ahead of our competitors in fuel cell miniaturization and operating efficiency."

The compact DMFC was developed in June 2004. It builds on existing DMFC technology, which powers larger-scale devices such as laptops.

Sample shipments of the fuel cell later this year for use in small handheld electronic devices are currently being planned.

In addition the company has promised continued development of its fuel cells, with the aim of making them even smaller and more compact.