As teensy nanotech devices get even tinier, the question of how to supply them with power becomes more pressing. Zhong Lin Wang, a nano-engineer at the Georgia Institute of Technology in Atlanta, is committed to finding the answer. As he described in a January Scientific American article, these devices (measured in nanometers, or billionths of a meter) could rely on nanoscale power plants, which would harvest waste energy from the ambient atmosphere or even from the human body.

Editor's Note: This story, originally printed in the July 2007 issue of Scientific American, is being posted in light of two new studies showing that angiogenesis inhibitors, discussed in this article, may actually make tumors bigger, not smaller.

Editor's Note: This story, originally printed in the January 2008 issue of Scientific American, is being posted due to a new study by the author, Zhong Lin Wang, on flexible nanowire energy generators.The watchmaker in the 1920s who de-vised the self-winding wristwatch was on to a great idea: mechanically harvesting energy from the wearer’s moving arm and putting it to work rewinding the watch spring.

Editor's Note: This story, originally printed in the September 1999 issue of Scientific American, is being posted due to a new study showing that nerve cells can be regenerated by knocking out genes that typically inhibit their growth.