Smaller power sources on the horizon

The pace at which scientists are developing new energy sources for portable electronics is dramatically speeding up as the industry races to make smaller devices with longer-lasting batteries.

Canadian government researchers at the Alberta Research Council (ARC) announced this week that they have built a working prototype of a fuel cell that uses hydrogen gas as a fuel but can be adapted to run on a variety of sources such as natural gas, butane or propane.

Meanwhile, a team from Cornell University last month unveiled a device that converts the energy stored in radioactive material directly into mechanical motion, which in turn moves the parts of a miniscule machine to generate electricity. This type of battery could supply power for decades, said Amit Lal, a professor at Cornell's electrical and computer engineering department and the lead researcher.

Lal said that medical device makers and cell phone makers have shown interest in commercial applications of the atomic battery, adding that consumers may see the new batteries in cell phones in about three to four years.

"If the size of the battery is an issue, then this component will consume negligible real estate," Lal said.

Such developments are part of a growing body of research coming out of university and corporate labs. The consumer electronics industry is focused on finding a way to replace the nickel cadmium batteries, which today power most portable electronic devices. Some researchers are also working on more efficient solar cells and methane-powered fuel cells.

With fuel cells and improved batteries becoming reality, the industry is likely to dramatically alter notebooks and cell phones, making them smaller but more powerful. New power technologies could extend the life of laptops two to three times longer than with current batteries.

Research scientists in ARC's advanced materials business unit have constructed a working demonstration unit able to power a small electric fan. The fuel cell consists of a small, hollow ceramic tube that is two millimeters in diameter and two centimeters in length.

"We're still in the early stages of research and development, but our focus is on developing an energy source that is easy to start up and will provide a high degree of power in a relatively small space, such as a cell phone, laptop or PDA," says Partho Sarkar, a senior research scientist at ARC.

Safety concerns, however, may stunt the acceptance of new fuel cells and batteries. The Cornell team will have to convince the industry that its batteries won't pose a radiation threat since they are powered by decaying isotopes. An isotope is an element with the same atomic number but different numbers of neutrons.

Lal said that he chose only isotopes that emit beta particles because their energy is small enough not to penetrate skin. Radioactive material can emit beta particles, alpha particles or gamma rays--the last two of which are carry enough energy to be hazardous, said Lal.

"We are focusing our attention to very small sources," said Lal. "The amount of radioactivity is so miniscule that you don?t have to worry about it as much."

The Department of Transportation last month removed one hurdle to the commercial acceptance of fuel cells powered by methanol by ruling that they could be taken on airplanes. The issue was that these fuel cells contain methanol, which is a flammable liquid.