  We consider a massless scalar field in 1+1 dimensions that satisfies a Robin
boundary condition at a non-relativistic moving boundary. Using the
perturbative approach introduced by Ford and Vilenkin, we compute the total
force on the moving boundary. In contrast to what happens for the Dirichlet and
Neumann boundary conditions, in addition to a dissipative part, the force
acquires also a dispersive one. Further, we also show that with an appropriate
choice for the mechanical frequency of the moving boundary it is possible to
turn off the vacuum dissipation almost completely.
