An interfacial phenomenon has been investigated, which is caused by putting a droplet of surfactant solution at an oil-water interface. When a droplet of camphor solution is put into an oil-water interface, an “explosion phenomenon” occurs, in which the oil phase is broken with a phase transition within a short time, e.g. less than 1 s in a system. The explosion phenomenon is repeated by putting another droplet, due to the sublimation of camphor. By using the explosion phenomenon with camphor solution, an impeller with a diameter of 5 mm shows a rotational motion with a rotational speed of 1 000 rpm, in which a reaction force of a jet by camphor solution is utilized. The direction and magnitude of the force generated by the explosion phenomena is controllable by giving an asymmetry of wetting property to a solid surface of an object, even if the shape of the surface is symmetric. In order to acquire a directional force with the asymmetry of wetting property, the gap between the wetting-controlled solid surface and an oil-water interface must be in a range, e.g. ±0.7 mm for the present experimental system.