Has nanotechnology had any success in mechanically separating "cold" atoms from "hot" ones, an application first dreamt up by Maxwell in the late 1800s?
I think a while back, they had machines to try to this. IIRC, they succeeded in doing it but in doing so, the machine created entropy which still satisfies the 2nd law of thermodynamics. So, it is still impossible to violate the 2nd law.