Dr. Sullivan has primarily worked with nondetonating reactive materials that produce rapid bursts of heat and gas when ignited. Such materials are of interest as pyrotechnics, or for systems such as airbag inflation or seat-ejection mechanisms. Most of his work has investigated the reaction mechanisms to find ways to extract the energy faster or slower, such that one material can be used for a variety of functions. At LLNL, he has continued this research and added the use of 3D printing to further understand phenomena occurring at the micro- and mesoscales. He has also expanded his efforts to other reactive materials of interest.