Roman's research focuses on microscale biophysical processes in the environment, with a special interest in the ocean. His group develops original microfluidic technology and image analysis techniques to understand microbes in the context of their physical (e.g., flow), chemical (e.g., nutrients) and ecological (e.g., other organisms) landscape, by directly observing microbes and making them 'come to life' for the non-microscopist. This novel approach has resulted in a broad range of fundamental new insights on microbial dynamics, particularly motility and chemotaxis.