Temperature and Humidity Dependence of Marangoni Convection and Its Effect on the Self-propulsion of an Oil Droplet

This paper reports the temperature and relative humidity dependence of self-propelled oil droplets. Self-propelled oil droplets locomote by internal Marangoni convection, which is caused by gradients in the interfacial tension due to surfactant and temperature gradients at the oil/water interface. We discover the external environment dependence of the self-propulsion of a droplet and discuss the mechanism of the property. Our study will serve as an innovative foundation for practical research, such as drug delivery systems.