Professor Clark's research is in the field of biochemical engineering, with particular emphasis on enzyme technology, biomaterials, and bioenergy. Current projects include structure-function relationships and biosynthetic applications of artificial metalloenzymes (with John Hartwig), mechanistic studies of adaptation to harsh environments by extremophilic microorganisms, protein design and assembly for the development of advanced biomaterials, and metabolic and bioreaction engineering for conversion of CO2 to fuels and chemicals.