You can be capable of creating a machine that actually moves for very long periods, even many years, and potentially eternally. The problem isn’t simply the motion itself, it is the fact that you cannot transfer that motion externally into work or energy. An atom, or any matter in this case, are examples of ‘perpetual’ motion in this sense. The trick isn’t to try to demonstrate devices that go on forever in exclusion of an external environment. You would have to show that such movement can create change externally while still not having to lose its own energy.
If you had a top (gyroscope) set spinning in an ideal space with the absence of absolutely everything, it will go on forever. This is already understood. Perhaps the term, “perpetual motion” throws people off because they recognize this but don’t understand why it appears to imply that things can never do this in a closed system. For this, I think it might be better to rename the concept perpetual energy devices. This would clarify better why such devices do not work. We probably only still call them, “perpetual motion” devices due to historical convention. The intent by those who have either sincerely or fraudulently attempted to create such devices were intended to find a means to create a source of perpetual energy, not merely cyclic motion.