Control of liquid flow using light (Invited Paper)

Nanometer-scale liquid droplets are of considerable interest across a wide range of interdisciplinary fields, including materials science, pharmaceutical processing, and nano-medical technologies, due to their potential applications in these areas. The conventional methods for generating and transporting these minuscule droplets have predominantly relied on mechanical pressurization and electric field-assisted techniques. However, these methods, while effective, often face limitations in terms of precision and control at the nanoscale. In response to these challenges, this invited paper introduces an innovative approach to liquid manipulation that utilizes the precise control capabilities of light momentum and energy. This method represents a significant departure from traditional techniques, offering a novel paradigm for the manipulation of liquid at the nanometer scale. The focus of this presentation will be on the recent experimental work conducted in the speaker's laboratory, which has successfully demonstrated the formation and ejection of liquid droplets from a specialized hollow optical fiber using continuous wave (CW) light at milliwatt (mW) power levels.