  Understanding and engineering the self-assembly of soft colloidal particles
(microgels) at liquid-liquid interfaces is broadening their use in colloidal
lithography. Here, we present a new route to assemble rectangular lattices of
microgels at near zero surface pressure relying on the balance between
attractive quadrupolar capillary interactions and steric repulsion among the
particles at water/oil interfaces. These self-assembled rectangular lattices
are obtained for a broad range of particles and, after deposition, can be used
as lithography masks to obtain regular arrays of vertically aligned nanowires
via wet and dry etching processes.
