Since cosmic rays are an enemy of electronic equipment, I wonder how well would a fluidics [1] system work, and where are the limits of miniaturization.
I'm not sure what fluid you'd be able to use on Venus' surface considering it's well over 400°C. Even mercury boils at 357°C.
Maybe use a gas?
The CO2 on the Venusian surface is a supercritical fluid. Not sure if that's any help - it's still compressible and so still acts like a gas more than a liquid.
Is that boiling point at 1 atmosphere?
Molten salts
Molten lead, maybe? It doesn't need to be a liquid on Earth.