STMicro Develops Fuel Cells For Cellphones, Portable Devices

New Delhi: | Updated: Nov 11 2003, 05:30am hrs
If you keep using up your cellphone batteries all the time, how about recharging the way a reusable cigarette lighter is refilled Chip maker ST Microelectronics claims to have had a technology break-through in developing small size fuel cells that can fit mobile phones, palmtops and even notebook computers.

The fuel cells for handhelds and notebooks could hit the market as early a year from now and costs are expected to be comparable with existing power-supply battery packs.

This would mean that handhelds and portable computing devices will be able to work longer without a recharge and refuelling will be possible through a small organic fuel can. ST Microelectronics is already in touch with the mobile manufacturers and expects to be ready with the first working prototype within the next six months.

An Italy-based research & development (R&D) team which is focussed on developing technologies and applications in areas not related to the core business of ST Microelectronics, has come up with smaller cells using cheaper membrane material to suit the needs of mobile devices and notebook computers.

Size and cost were the two biggest challenges in developing smaller fuel cells. In fuel cells, the physical area should be equal to active area (a surface of membrane used for electrode reactions) to generate current. Considering this, it was practically not possible to pack a fuel cell of the requisite size inside a mobile phone. But we have succeeded in developing a three-dimensional (3D) structure to reduce the cell size, Dr Salvo Coffa, who leads the Corporate Technology R&D team of the company, told eFE in an exclusive interview.

The other big challenge was to develop cheap material for the membrane inside the fuel cells and the research team was able to achieve this, he said.

He added that other smaller problems were related to water management and control of temperature.

The ST research team has also succeeded in fabricating a special nanoporous layer, consisting of a layer of silicon

containing millions of pores, each measuring just a few nanometers in diameter, he added.

We expect to develop the first working prototype within the next six months. We have already had informal discussions with cellphone vendors for commercialisation of this new fuel cell technology, added Mr Coffa.

A fuel cell is a device that generates energy using electrochemical reactions instead of fuel combustion. In recent years, there has been enormous interest in fuel cells because they promise to deliver cheap, clean energy. Although much of the work in the emerging field of fuel cell technology has been aimed at automotive applications, this is the first time a possibility of using tiny fuel cells was worked out to suit the need of small devices.

Using fuel cells instead of batteries would make mobile phones lighter and much more convenient to use as they could be simply topped up with fuel whenever necessary. In addition, there would be significant environmental benefits as the fuel can be derived from sustainable organic sources, while the by-products are mainly water and a much lower level of carbon dioxide than is produced by burning fossil fuels, said Dr Coffa.

The operation of a fuel cell involves the chemical interaction between hydrogen and oxygen to produce water, heat and electrical energy.

Typically, a fuel cell consists of a pair of electrodes (the anode and the cathode) separated by a membrane that allows protons (hydrogen ions) to pass through the membrane but does not allow an electric current to pass.