Over dinner, my son (3rd grade) talked about a video they watched at school about a young girl who invented a flashlight that worked by the heat of your hand. I later found the video here: http://www.youtube.com/watch?v=9CCGUMkcbjg. Big congrats to her, way to go!
This led into an excellent conversation about alternative energies sources and the related law of conservation of energy as they got excited about powering a car with the heat of your hands. And no, kids, driving barefoot to add the heat of your feet would unfortunately not add enough energy to the system. But it would be an awesome throwback to the Flintstones! I encouraged the brainstorming for as long as the chips and salsa held out.
Later, at home I pulled out the peltier plate I got for the Frankenstein project (not as sinister as it sounds) and hooked it up to my multimeter. The peltier plate is a component that will convert a heat difference between the two sides into electricity. This is the principle the young lady used to power her flashlight.
|Simple Setup - Multimeter leads clipped to peltier leads|
The kids then took turns putting their hand on the plate and watching the voltage change.
|Ok, so not my kid's hand. Consider this a reenactment.|
A simple learning moment that only required one electrical component and a multimeter.
P.S. Yes the voltage in the picture is negative, flip the plate over or flip the leads if that matters to you.