Paul Weiss explores the ultimate limits of miniaturization, designing, assembling, and operating the world's smallest switches and motors, including developing and applying both the tools to place single molecules and assemblies in controlled chemical environments, adding the chemical dimension to nanolithography and revolutionary new nanoscale analysis tools that enable the measurement of structure, function, and spectra with submolecular resolution. The journal he founded, ACS Nano, has, in only nine years, risen to 18th most cited in all fields. He has been honoured by many organizations, including the American Chemical Society, the American Physics Society and the AAAS. He has contributed to Canada through invited lectures at the University of Alberta and hosting Canadian Fulbright Chairs.