  Our previous article [Phys. Rev. Lett. 104, 060401 (2010)] predicted that
Casimir forces induced by the material-dispersion properties of certain
dielectrics can give rise to stable configurations of objects. This phenomenon
was illustrated via a dicluster configuration of non-touching objects
consisting of two spheres immersed in a fluid and suspended against gravity
above a plate. Here, we examine these predictions from the perspective of a
practical experiment and consider the influence of non-additive, three-body,
and nonzero-temperature effects on the stability of the two spheres. We
conclude that the presence of Brownian motion reduces the set of experimentally
realizable silicon/teflon spherical diclusters to those consisting of layered
micro-spheres, such as the hollow- core (spherical shells) considered here.
