He has played a leadership role in the National Nanotechnology Initiative, nanoscale science and engineering research and education, particulate and multiphase systems, and in developing perspectives on the societal implications of nanotechnology. He pioneered convergence science, identifying basic theories, principles and methods for convergence, and applied it to various platforms such as convergence of nanotechnology with bio-, cognition-, digital-, AI and other fields for various goals, in what is sometimes called converging and emerging technologies. Convergence research for universal processes in nature and society has become an international endeavor since 2001. He is credited with thirteen patents and has contributed over two hundred articles and twenty books on mass transfer, rotating machinery, multiphase systems, computer simulations, nanoparticles and nanosystems, intelligent cognitive assistants, trends in emerging technologies, knowledge convergence and societal implications. He is a co-founder and past Chair of the AIChE Particle Technology Forum.