Microactuator driven by a new type of capillary force

We present a new kind of capillary force on a couple of immiscible liquid; Fluorinert and silicone oil. Fluorinert is a type of fluorine compound produced by 3 M. When a drop of silicone oil was poured on a Fluorinert layer, spontaneous convection was observed. Driving force of this flow is considered to be the distribution of surface tension. Thermo-capillary convection or solute-capillary convection was noted, however this new type of convection is considered depending on evaporation. As well known, for micro-scale phenomena, wetting and surface tension are dominant. These two forces are also dominant under microgravity conditions, and thus when we carry out microgravity experiments we are aware of their presence. This new capillary convection was discovered during the preparation of microgravity experiments. The driving force point seemed to be at the liquid-liquid-gas triple meeting point. The fact that this driving force does not need any mechanical system leads to the possibility to build very small actuators. Promising application area of this method is not only the development of micro-actuators but also the handling of fluids in space.