Core77.com’s “Greener Gadgets Competition” shows up a system invented by Alexander Parker, that could power your laptop, cellphone, or other device that has buttons as an input, to an extent that could replace your battery (for example, if you write a lot, you could write more).
Assume that if for each character in a text message a button is pressed once, each text message uses the entire allotted 160 characters, everybody in the US owns at least one cell phone, and each American person texts, on average, 1.4375 texts per day. This would mean that 229.99 buttons are pressed, in texting alone, per day, on a cell phone.
The principle uses the piezoelectric effect to create a small amount of energy (0.5W). It works like the cigarette lighter in your pocket. The piezoelectric effect is based on the properties of some materials (like quartz crystals) to generate electrical energy when they are applied mechanical energy. Now, I don’t know if this wouldn’t make your key touches more stiff, and your fingers more strong in time, but it’s sure nicer than spinning a wheel to rotate an dynamo, isn’t it?
Parker estimates that by eliminating wall outlets for charging he cellphone, a single person a can save nearly 0.144kW a day, or 52.560kW a year.
Below there are two more pictures of this great invention. Click on them to enlarge. Someone should try doing this for real!