The last thread was locked, DEUT is not conductive, which was one of the key elements of this suggestion!
Mercury
When it is heated, it grows like yeast up to a certain point (like , say 5 pixels per degree C or something, I don't know) When is is cooled, it shrinks, up to a certain point (see above, but in reverse)
It is conductive
Why? You ask. Well:
1. Thermometers
2. Things that are hot heat up mercury, it lets an electric charge past, opening an E-wall that releases cold fire until the thing has cooled down enough, then it shuts off as the mercury is too low to let the charge past.
3. I'm sure the community will be able to use it to make more things ;)
Instead of making a whole new element to make a conductive version of DEUT, just use Detector walls to produce spark on contact.
That's the way people usually make their electronics work, and sparking liquids stops them from moving anyway for the brief time they're sparked, which would make sparking mercury a bit weird to stick in a tiny barrel for a thermometer.