Thermal response of Bessel beam-heated microdroplets carrying nanoparticles for deposition

Abstract

Laser-microdroplet interactions influence the quality of nanoparticle deposition on a substrate. When a microdroplet and its impinging spot are heated, the microdroplet can evaporate gently, boil immediately after impingement, or bounces back inhibiting the deposition process. The interaction between a laser and droplets carrying semiconductor and metal nanoparticles is studied for different laser powers. The results indicate that the laser is refocused by the droplets, and deposition of nanoparticles and formation of nanofeatures are achieved under certain conditions. On the other hand, when the laser power exceeds a critical value, heating up the substrate at a specific temperature, microdroplets bounce back from the substrate, except for the cases of liquids with low reflectance coefficient and high absorption coefficient, where a new laser-spraying regime is observed.