  The notion of nanomachines has recently emerged to engage and use collective
action of ensembles of nanoscale components or systems. Here we present a
heat-gradient driven nanomachine concept which through appropriate coupling
between quantum nanosystems is capable of realising and maintaining an
inversion. Based on a Lindblad form of the Quantum Master Equation with a
semiclassical coupling to the lattice displacement phonon field we show that
this positive inversion can be harnessed to generate coherent optomechanical
oscillations and phonon lasing.
