Just as a machine won't run without a source of power, a device built at the nano-scale is of little use if it doesn't have the energy to work as a sensor or drug delivery particle.  Since there isn't a battery in existence yet that's small enough to couple with a nanodevice, researchers have sought to power such microscopic creations with energy drawn from their surroundings. This energy so far has come primarily from chemical reactions (such as the oxidation of hydrogen peroxide), but that may change. A new study published today in Science describes the creation of a nanogenerator that transforms kinetic energy into a continuous flow of direct-current (DC) electrical energy.

Zhong Lin Wang, director of the Center for Nanostructure Characterization at the Georgia Institute of Technology, says the kinetic energy can come from a variety of sources, including ultrasonic waves, mechanical vibration or blood flowing through the body. (Wang wrote about self-powered nanotech machines for the January 2008 issue of Scientific American.)

The world needs a "revolution" in science and technology to solve global warming, says Energy Secretary Steven Chu.

Chu, a Nobel Prize-winning physicist, made the remarks in today's New York Times. The article was short on specifics, but Chu, former director of Lawrence Berkeley National Laboratory, said Nobel-level breakthroughs were needed in electric batteries, solar power and crops that could be turned into fuel. "Science and technology can generate much better choices,” Chu, a long-time proponent of alternative energy development, told the newspaper. “It has, consistently, over hundreds and hundreds of years.”

The company that killed the electric car is ready to resuscitate it. General Motors (GM) this week laid out plans at the Washington (D.C.) Auto Show to prepare communities for the 2011 debut of its Chevy Volt and plug-in electric vehicles that other automakers are set to start building next year. So where are they likely to show up first? Washington, D.C., and San Francisco, GM says, noting that those cities not only have ready-made markets for its lithium ion battery-powered Volt  but, also, have a history of welcoming new kinds of cars (like the Volt's predecessor, the EV-1).

See a Scientific American.com slide show featuring the Volt

As devices shrink to microscopic proportions they need similarly-sized batteries to make them run. Although no such batteries exist today, a team of Massachusetts Institute of Technology (MIT) researchers this week reported in the Proceedings of the National Academy of Sciences (PNAS) a breakthrough in their work to create a microbattery that's small enough (yet powerful enough) to run a range of miniature devices, including labs-on-a-chip and implantable medical sensors.

(From left, professors Yet-Ming Chiang, Angela Belcher and Paula Hammond display a virus-loaded film that can serve as the anode of a battery in 2006. Photo courtesy of Donna Coveney, MIT)

The researchers, who include MIT professors Angela Belcher, Paula Hammond and Yet-Ming Chiang, made and positioned the mini-electrodes required to make such a small battery with help from the M13 virus, which is 6.5 nanometers in diameter and 880 nanometers in length. Belcher was Scientific American's 2006 Research Leader of the Year, and is well-known for her work engineering the M13 to latch onto and coat itself with tiny specks of semiconductor material (such as gold and cobalt dioxide), yielding metal nanowires that could be assembled into high energy-density electrodes.

The world’s major auto companies have yet to bring an electric vehicle (EV) to market and keep it there for long. Some drivers, however, taunted by stratospheric gasoline prices, have taken matters into their own hands.

They are retrofitting their gas-guzzlers into their own DIY EVs.

A company catering to these gas-averse early adopters is Electric Vehicles of America, a New Hampshire-based company that sells you the parts in a kit and gives instructions to convert a fuel-dependent vehicle—from a pick-up truck to a boat—into an EV.

Unfortunately, the electric-conversion enthusiasts are banging up against the same technological ceiling that the big boys have yet to shatter: limited range. One vehicle mentioned in a recent CNN report, a 1995 Chevy S-10 pickup, runs on 20 six-volt, lead-acid batteries and got only 40 miles between charges. Bob Batson, the founder of Electric Vehicles of America, notes, however, that the average driver only logs 20 miles per day, so such an EV could work for some people.