  The concept of fluctuation-induced effective interactions is extended to
systems driven out of equilibrium. We compute the forces experienced by
macroscopic objects immersed in a soft material driven by external shaking
sources. We show that, in contrast with equilibrium Casimir forces induced by
thermal fluctuations, their sign, range and amplitude depends on specifics of
the shaking and can thus be tuned. We also comment upon the dispersion of these
shaking-induced forces, and discuss their potential application to phase
ordering in soft-materials.
