  We present two novel models for repulsive Casimir interaction between
positive perturbations. One example relies on non locality of the dielectric
response and one relies on interference between (attractive) modes. Such
examples are impossible to achieve in 1d massless theories, as they are
prohibited by a generalization of the result of Lambrecht, Jaekel and Reynaud
[Phys.Lett. A 225 (1997)] to non local dielectrics and to negative
perturbations
