Optofluidics combines and integrates optics and fluidics to produce versatile systems that are achievable only with difficulty through either field alone. With the spatial and temporal control of the microfluids, the optical properties can be varied, providing highly flexible, tunable, and reconfigurable optical systems. Since the emergence of optofluidics, numerous systems with varied configurations have been developed and applied to imaging, light routing, bio-sensors, energy, and other fields. This Special Issue aims to collect high quality research papers, short communications, and...