The transport of microliter-scale droplets on solid surfaces is critical for various applications, including microfl uidics and

microengines. Recently, droplet manipulation strategy using thermocapillary convection has received attention due to its

precise and remote controllability. The mobility of liquid droplets in this method depends on several parameters, such as laser

power and the light absorption coeffi cient. Additionally, surface tension signifi cantly infl uences droplet movement although

its underlying mechanism remains unclear. In this study, we investigate the eff ect of surface tension on droplet movement

via thermocapillary convection. Aqueous dispersions of polypyrrole (PPy) nanoparticles (NPs), which absorb near-infrared

(NIR) light and convert it into heat, are employed as droplets. Upon NIR laser irradiation, the PPy droplets generate localized

heat, resulting in thermocapillary convection. The lubricated surface (LuS) is used as a substrate. Due to the mobile

lubricant layer, droplets are easy to move with low friction. Surface tension is modifi ed by adding a surfactant, and the

droplet movement speed increases with decreasing surface tension. Here, this phenomenon is investigating the parameters

acting to Marangoni force: contact line length and surface tension gradient. We confi rm that the Marangoni force, which

propels the droplet, is induced more eff ectively by low surface tension liquids. This study provides fundamental insights into

droplet behavior governed by wettability diff erences, advancing droplet manipulation techniques for diverse fl uidic systems.