There are many different types of capacitors, most of which don’t contain any liquid at all (including the most common type - ceramic capacitors).
But in general, you would use specially rated components and materials if you need them to last decades - not the cheapest most basic parts you can find.
Other types of implanted devices have dealt with the same things decades ago.
I don’t know what components exist on the neuralink boards, but i do know that capacitors are pretty common and tend to leak after a couple decades…
There are many different types of capacitors, most of which don’t contain any liquid at all (including the most common type - ceramic capacitors).
But in general, you would use specially rated components and materials if you need them to last decades - not the cheapest most basic parts you can find.
Other types of implanted devices have dealt with the same things decades ago.
Yes, capacitors have a lifetime which decreases if they experience heat.