The uses of piezoelectric disks

[ninja.lion]

can small piezoelectric disks 3.7x3.7 cm inside a tube with a buzzer at the other end be able to power an LED

 

[jedishrfu]

Here's some discussion on piezo-electricty that discusses usages:

http://en.wikipedia.org/wiki/Piezoelectricity

One such usage was to harvest the electricity of walking with special military boots to get back 1 to 2 watts of electricity but the boots were too uncomfortable to wear.