NOVELTY - A two-dimensional or three-dimensional inorganic structure is formed in situ within a microgel encapsulation.    USE - As a two-dimensional or three-dimensional inorganic structure encapsulated in microgel useful as two-dimensional and three-dimensional array in a fixed bed reactor for the production of hydrogen gas (claimed); useful for a variety of applications including batteries, supercapacitors, fuel cells, solar cells, photo-oxidation reactors, display devices, electronic devices, biotechnological devices, optical devices and biosensors.    ADVANTAGE - The co-encapsulation of photoactive and catalyzing materials within microgel provides long-term stability to the composite. The composite microgels can be disposed in ordered structures which can improve device efficiency, e.g. a reactor tube comprising an ordered array of microgels. The composition is a protective polymer network encapsulating the inorganic structures and act as a protective layer for the inorganic material when used in a battery. Metal oxide microgels accumulate lithium ions through intercalation. The mobility of the nanoparticles within the microgels and mobility of the microgels themselves allow the microgels to accumulate and discharge lithium ions without cracking. The lithium ions are accumulated by the microgel composition via deposition of lithium oxide on the surfaces of the micro- or nanoparticles or nanotubes through standard electrochemical mechanisms, e.g. through the oxidation of lithium and the reduction of cobalt or other oxidized metals in the microgels. The high surface area of the virus-based nanotubes within the microgel provides additional reaction sites for lithium ions as they intercalate through and between the nanotubes, thus potentially increasing the capacity of an electrode comprising the microgel compositions. The compositions including a cross-linked ion-conducting polymer can provide a chemically robust barrier to prevent the electrode material from being exposed to the organic solvent directly.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) method of forming microgel, involving either loading viruses, peptides, or biomineralizing molecules into a polymer network during the formation of pre-microgel droplets and solidifying the droplets into microgels by exposure to radiation; or loading microstructures or nanostructures into a polymer network during the formation of microgels and solidifying the microgels by exposure to optical radiation; and    (2) a microfiuidic apparatus comprising a supply capillary; a collector capillary disposed within the supply capillary, and having a tapered end with a small orifice which receives at least two fluids from within the supply capillary; and a source of radiation illuminating a region of the inner capillary; where an inner fluid is hydrodynamically focused into the collector capillary and breaks into droplets within the inner capillary, and the droplets move downstream and pass through the region illuminated by the source of radiation.