Are there designs that don't use thermal paste? As I understand it regardless of solution you need paste or live with significantly reduced conductivity. That goes for any system - fan cooled, liquid cooled, passive,...
Graphite thermal pads are available for consumers (e.g: Thermal Grizzly Carbonaut,
IC Diamond Graphite) which offer similar performance (within 5°C) to paste without this issue.
Edit: to answer my own question it looks like Apple uses thermal paste but the cooling in the M2 MacBook Air looks extremely flimsey to the point of being almost non-existent. I doubt it will be affected much at all by this.
You're looking for phase change materials (PCM), which soften at the desired operating temperature. Prevents pumping out because it's still mostly-solid.
>> Are there designs that don't use thermal paste?
Yes. Glue. Paste is for when you might want to one day separate part from heatsink. If you don't care about repairs, it is perfectly reasonable to just glue them together with thermal adhesive.
