A gel assembly comprising a polymeric gel layer between metal layers. A gel assembly process comprising providing a colloidal polymer in solution, drying the solution to form a polymeric gel layer and forming metal layers on either side of the polymeric gel layer. A method of drug delivery comprising loading a polymeric gel layer with drug, forming metal layers on either side of the polymeric gel layer, wherein the polymeric gel layer comprises a material that is sensitive to a stimulus, and subjecting the polymeric gel layer to the stimulus to release the drug from between or through the metal layers.