sure there maybe other advanced infinite energy engine devices
but for now the only forceeable one would have to indicate the domino effect being its prime blue print for the design
domino effect=a phase that needs only a small amount of energy to begin with that that can return back the energy infinitly fold.
i know many of you are architects and engineers today i will be working and mind masterbating at the thought of such great things. As you can see its certainly acheivable, it makes sense already, the physics are something that could be imagined im certain of