Translationally invariant colloidal crystal templates

We show that dynamic, feed-back controlled optical traps, whose positions depend on the instantaneous local configuration of particles in a pre-determined way, can stabilise colloidal particles in finite lattices of $any$ given symmetry. Unlike in a static template, the crystal so formed is translationally invariant and retains all possible zero energy modes. We demonstrate this $in-silico$ by stabilising the unstable two-dimensional $square$ lattice in a model soft solid with isotropic interactions.