Collapsing backpack charges gadgets as you walk
WEARABLE computers are on their way and soon you'll be able to power them yourself. A new type of nano-generator converts movement from walking into electricity to keep your gadgets going.
Wearable generators often use electromagnetic induction, which is efficient but requires bulky, heavy magnets. Smaller, lighter piezoelectric generators use ceramic crystal to convert pressure into voltage, but they are expensive and a lot less efficient.
Now Zhong Lin Wang and colleagues at the Georgia Institute of Technology, Atlanta, have captured the electricity generated from bringing two differently charged surfaces into contact, then separating them. This is called the triboelectric effect, the same process that causes static electricity shocks.