For those late night coffee binges where it is crucial that you are aware of the location and existence of hot coffee, a coffee cup that merely changes color won't cut it.

Instead, this cup has a thermoelectric generator embedded in in which generates power from the heat gradient. This voltage is used to drive LEDs embedded in the glaze (diswasher safe, of course) which spell the word "HOT" or other (perhaps animated) promotional messages.

I'm thinking a couple OLED pixels might draw little enough power for this to work -- otherwise, we may have to charge a capacitor for the occasional scintillation.,..

A related (and perhaps more power efficient) cousin of this cup provides electronically driven patterns via e-ink or LCD underneath the glaze (displaying the temperature might be neat).
-- cowtamer, Feb 26 2010

Thermoelectric lamp http://www.instruct...thermoelectric-lamp
[cowtamer, Feb 26 2010]

Joule Thief LED Driver http://hackaday.com...e-thief-led-driver/
Drive LEDs from low voltages [cowtamer, Feb 26 2010]

Heat Recycling Coffee Mug Heat_20Recycling_20Coffee_20Mug
[phoenix, Feb 26 2010]

I'm sure we've done something like this before, but I'll be damned if I can find it.
-- phoenix, Feb 26 2010



random, halfbakery