The invention provides cryogels whose porosity, pore size, pore connectivity, swelling agent concentration, and/or specific volume undergoes a change from a first value to a second value in response to an electrical stimulus. The cryogels have interconnected macropores which greatly enhance their ability to rapidly undergo volumetric collapse when subjected to moderate electric fields. The cryogels of the invention can be easily integrated into arrays capable of rapid configurational and chromatic optical modulations, and when loaded with drugs, are able to coordinate the delivery profile of multiple drugs. The cryogel can be prepared by polymerizing an aqueous solution of charged monomers and cross-linker monomers at a temperature below the freezing temperature of the solvent.