Dr. Simmons has worked on a wide variety of projects for nearly 30 years ranging from vehicle light-weighting to pressure vessels for hydrogen storage to hydrogen compatibility. His current focuses on investigating the effects of hydrogen interactions with polymers through multiscale modeling and experimental research. Current research has focused on model compounds of EPDM and NBR elastomers and the influence of high-pressure hydrogen gas and temperature on the material and their additives that influence the material's sealing performance. Dr. Simmons was the task lead for the Department of Energy's multi-lab, multi-company Hydrogen Storage Engineering Center of Excellence for hydrogen pressure vessels, containment, and balance of plant components. He led the effort to reduce costs, volume, and mass, and developed a balance of plant library. Through his experience, he gained an appreciation for the limited body of knowledge for hydrogen compatibility in polymers and elastomers at pressure and temperature. Dr. Simmons is currently co-leading for two multinational lab-led hydrogen materials compatibility programs (H-Mat) and evaluating natural gas distribution infrastructure for materials compatibility with blended natural gas and hydrogen (HyBlend) for the Department of Energy. He is a Battelle Distinguished Inventor, has 20 US Patents, multiple Foreign Patents and patents pending, two R&D Magazine R & D 100 Awards, and one Federal Laboratory Consortium Award for technology transfer.