Pattern formation in polymer films by non-linear processes

When a droplet of a dilute solution of a polymer is allowed to evaporate on a horizontal substrate, the polymer is deposited on the substrate as a reg ular 2 dimensional pattern of micrometer-sized polymer droplets or lines. I t was found that the mechanism of the pattern formation involves a Benard c onvection in the polymer solution and a regularly spaced fingering instabil ity at the contact line of the solution with the substrate. By using liquid crystalline polymers, a novel hierarchic pattern can be observed.