Friday, September 15, 2006

Bacteria-Powered Batteries


Print this pageAdd to favorites

Posted by George Elvin on September 15, 2006 - 8:00am.

The computer you're reading this on may be about to explode. That was the gist of the message I received from my university's security department the other day. It seems the lithium ion batteries that power some computers have been spontaneously bursting into flames. That got me looking into alternative batteries in a hurry, and it didn't take long to figure out that most batteries are bad news for the environment.

The lithium ion batteries that power today's computers, PDAs, and cellphones use flammable solvents. And while the federal government deems them non-hazardous waste safe for disposal in landfills, the acid batteries found in cars can leach cadmium and other heavy metals into the soil.

Fortunately, a new breed of batteries currently under development in nanotechnology and biotechnology labs may offer a safer, more environmentally sound alternative. Nano titanate batteries will power electric cars, and nanogenerators will draw power from body movement and even bloodflow to charge implants and medical devices.

But perhaps the most intriguing alternative of all is the bacteria-powered battery now in development at several labs. A team of researchers at the Department of Energy's Pacific Northwest National Laboratory, for instance, has created "bio-batteries" by causing tiny microbes to sprout electrically conductive nanowires. The wires, about a millionth of a meter thick, "will literally reach out and connect cells from one to another to form an electrically integrated community," said Yuri Gorby, staff scientist at the lab.

"The effect is suggestive of a highly organized form of energy distribution among members of the oldest and most sustainable life forms on the planet. Earth appears to be hard-wired," concluded Gorby.

Not to be outdone, researchers at MIT have created genetically engineered viruses to act as scaffolding for ultra-thin, transparent electrodes capable of storing nearly three times as much energy as today's lithium ion batteries.

"If you can make batteries that truly are effective this way, it's just mind-boggling what the applications could be," University of Texas at Austin professor of organic chemistry and biochemistry Brent Iverson said of the MIT feat.

Mind-boggling applications are exactly what the MIT folks have in mind. "Most of it was done through genetic manipulation," said Angela Belcher of the MIT team in an interview with Technology Review, "giving an organism that wouldn't normally make battery electrodes the information to make a battery electrode, and to assemble it into a device. My dream is to have a DNA sequence that codes for the synthesis of materials, and then out of a beaker to pull out a device. And I think this is a big step along that path."

And while the day when we can encode DNA to grow devices in beakers may be a way off, there are enough devices in development today using bacteria-powered batteries and bio-batteries to make that famous pink bunny green with envy.

The new National Center for Design of Biomimetic Nanoconductors is already at work designing bio-batteries for a wide range of implantable devices, starting with an artificial retina.

Other applications could include high-energy batteries laminated invisibly to flat screens in cell phones and laptops or conformed to fit hearing aids. The same assembly technique could also lead to more effective catalysts and solar panels.

Today's batteries are some of the worst environmental offenders. Bacteria-powered and bio-batteries may offer a safer, more sustainable alternative. And while the bioengineered devices and implants they will power raise legitimate ethical concerns, they may also bring major advances in health, safety and sustainability. At the very least, they'll be an improvement over exploding laptops.

Info on recycling standard batteries here.

Photo courtesy of the National Center for Design of Biomimetic Nanoconductors



Post a Comment

<< Home