After a Fulbright Fellowship at the MPI fuer Stroemungsforschung in Goettingen, Germany (1989) and postdoctoral work at the IBM T. J. Watson Research Center (1990–91), Ruoff became a staff scientist in the Molecular Physics Laboratory at SRI International (1991–1996).

[52] His predictions with A. L. Ruoff about the mechanical response of fullerite under high pressure,[1] and his work with colleagues on the unique solvation phenomena of C60 in various solvent systems,[15][16] and of synthesis and structural characterization of supergiant fullerenes containing single crystal metal ‘encapsulates’,[21] have demonstrated to the scientific community the novel properties of closed-shell carbon structures.

He also co-developed a new in-situ mechanical testing device for measuring the tensile response of bundles of SWCNTs and individual MWCNTs inside of a scanning electron microscope.

[4][5][6][12] This work has yielded important insights into the mechanics and tribology of these systems, and suggested the possibility of very low friction linear bearings.

[23][24] From 2009, Ruoff and collaborators have demonstrated synthesis of large area monolayer graphene on copper foil by chemical vapor deposition,[25][27][28][29] for which relatively high carrier mobilities have been obtained, and subsequently have used isotopic labeling and micro-Raman mapping to map grains and grain boundaries in such atom thick layers and to elucidate growth mechanisms,[30] and studied their performance as transparent conductive electrodes.

[26] Ruoff and his collaborators have also made a series of advances in novel composite systems comprising chemically modified graphene platelets.