There's a new tank called the Altus that is using a different type of heating element that supposedly never has to be changed (they call it an "advanced solid state heater"). You only have to rewick the cotton every so often, but the "coil" lasts indefinitely. A user on reddit is speculating what the heating element is. I will quote him:
I'm almost 100% positive that the "CVU" is just a
silicon nitrate heater with tungsten (or some alloy of it) as the resisting heating element. I can understand why they don't want you to dry burn it, it would cause an expansion of the metal which would cause the inner layer of the CVU to turn into liquid-y phase silicon nitride (still a solid, but it expands under high heat) which would then COULD cause the solid-b phase outside to crack under expansive force. Dont worry about dropping it and breaking the CVU though, Silicon Nitride has a Density of 3.2 kg/m3 , nearly the same as diamond.
Sounds interesting and I am anxious for reviews and a thorough breakdown of the "CVU."
In any case, the inventor has made a video showing how to wick it.