Light-induced microdroplet suspension and directional self-driving.

In this Letter, we show stable suspension and directional manipulation of microdroplets on a liquid surface employing simple-mode fiber with a Gaussian beam at 1480-nm wavelength using the photothermal effect. The intensity of the light field generated by the single-mode fiber is used to generate droplets of different numbers and sizes. In addition, the effect of the heat generated at different heights from the liquid surface is discussed through numerical simulation. In this work, the optical fiber is not only free to move at any angle, solving the difficulty that a certain working distance is needed to generate microdroplets on free space, it can also allow the continuous generation and directional manipulation of multiple microdroplets, which is of tremendous scientific relevance and application value in promoting the development and cross-fertilization of life sciences and other interdisciplinary fields.