the present invention relates to polymer - bead composites having a single layer planar , crystalline assembly of encoded beads embedded in a hydrophilic polymeric matrix . the composite may be unattached to a solid support . the encoded beads have different biomolecules attached to their surfaces , and the encoding permits distinguishing beads having different biomolecules attached thereto . the present invention also relates to a systematic process for the creation of functionally organized , spatially patterned assemblies of polymer - microparticle composites , including the ac electric field - mediated assembly of patterned , self - supporting organic films and organic - polymer - microparticle composites of tailored composition and morphology . the present invention also relates to the application of such functional assemblies in materials science and biology . additional areas of application include sensors , catalysts , membranes , and micro - reactors , and miniaturized format for generation of multifunctional thin films .