The fluorescent poly(1,3,4-oxadiazole)s (POD) and polypyrene (PPy) were examined for electro-optic device. The fluorescence switching device prepared using poly(1,3,4-oxadiazole)s showed molecular structure-dependent switching properties depending on the para- or meta-linkage. Thin films of POD and PPy were prepared by solution process to give highly fluorescent film, of which emission intensity was switched on and off upon application of step potentials. Using a photochemical reaction, the thin films of POD and PPy were directly patterned to give a fluorescent pattern. An all solid state device containing the patterned films of POD and PPy was prepared using a solid polymer electrolyte layer. The device showed reversible fluorescence switching in response to external voltage applications. Patterning of the switching device in different dimension and scale will be demonstrated.