Patterning of layer-by-layer assembled organic-inorganic hybrid films: imprinting versus lift-off

Layer-by-layer (LbL) assembled organic-inorganic poly(acrylic acid) (PAA)/poly(allylamine hydrochloride) (PAH)/ Au nanoparticle hybrid films are patterned by using Norland Optical Adhesive 63 (NOA 63) polymer molds. Depending on the rigidity of the hybrid films, their patterning can be realized by a room-temperature imprinting or lift-off process. For [(PAA/PAH)1-(Au nanoparticle/PAH)3]*10 and [(PAA/PAH)3-(Au nanoparticle/PAH)3]*5 films which have a low content of Au nanoparticles, the films can be imprinted at room temperature to form patterned films with large areas because of the compressibility and fluidity of the films under high pressure. The Au nanoparticle/PAH films, which have an extremely high content of Au nanoparticles and are fragile, can be patterned by a lift-off process during which the film contacted with the NOA 63 mold was peeled off because of the strong adhesion between the film and the mold and the fragility of the film. The complementary room-temperature imprinting and lift-off methods with polymer NOA 63 molds provide facile and general ways to pattern LbL assembled organic-inorganic films with various film compositions.