Method for synthesizing a specific, surface-bound polymer uniformly over an element of a molecular array

A method for specifically and uniformly synthesizing desired polymers within molecular array elements. Droplets containing a reactive monomer are successively applied to the elements of a molecular array in order to synthesize a substrate-bound polymer. Application of an initial droplet, having a first volume, defines the position and size of a molecular array element. Subsequent droplets are applied, to add successive reactive monomers to growing nascent polymers within the molecular array element, with covering volumes so that, even when application of the subsequent droplets is misregistered, the entire surfaces of the elements of the molecular array are exposed to the subsequently applied droplets. Following application of initial droplets, the surface of the molecular array is exposed to a solution containing a very efficient capping agent in order to chemically cap any unreacted nascent growing polymers and any unreacted substrate molecules.