BBC Focus Magazine

[Shadowwolf]

Researchers have discovered yet another way to harvest small amounts of electricity from motion in the world around us -- this time by capturing the electrical charge produced when two different kinds of plastic materials rub against one another. Based on flexible polymer materials, this "triboelectric" generator could provide alternating current (AC) from activities such as walking.

The triboelectric generator could supplement power produced by nanogenerators that use the piezoelectric effect to create current from the flexing of zinc oxide nanowires. And because these triboelectric generators can be made nearly transparent, they could offer a new way to produce active sensors that might replace technology now used for touch-sensitive device displays.

http://www.sciencedaily.com/releases/2012/07/120709150612.htm

[Jamie]

I seem to remember a similar idea using paving slabs to generate electric when people walk over them.

[M Paul Lloyd]

I don't know why they don't just fit them with folding hand cranks, its a bit retro.... possibly even Steam Punk in concept but at least it would provide a modicum of physical exercise.

[Jamie]

Worked for wind up radios. Perhaps a wind up charger for multiple devices would be a better idea?

[M Paul Lloyd]

They do make those, indeed I have one, but I reckon it could be handier if it were actually bigger and better made so that you didn't have to wind the handle like a demented ferret on speed for half an hour to provide a decent charge. .

[Willxx]

I seem to remember a similar idea using paving slabs to generate electric when people walk over them.

company called Pavegen -
http://youtu.be/EjYMa46_k70

saw them at a exhibition couple of years ago. It looks to be a perfectly practical system for high traffic areas, even if it only contributes a little to the overall demand for power surely this is better than not bothering at all?

[M Paul Lloyd]

It does rather depend on the unit costs per paving slab Willxx, plus the environmental impact the production and installation of same would have over its useful working life, and once you add all of that together it often wipes out any benefits completley.

A bit like wind farms, that seem like such a good idea on paper but which struggle to cover their own production carbon footprint even when the right sort of wind does blow.