duracell power strips

[Immi666]

how do those battery power strips work? all i know is that u put ur fingers on the little dots.

[Catso]

I speculate...

Your fingers complete a circuit, which puts the battery's power through a conductive strip, which heats up (slightly) as a result. There's temperature sensitive liquid crystal above the strip, and this changes colour as it is heated up.

The shape of the heating bit changes along its length, so at one end it is harder to heat up than the other.

You could just look for it on wikipedia.