220 Progress of Theoretical Physics Supplement No. 161, 2006 Spontaneous Motion of a Droplet Coupled with Chemical Reaction

The spontaneous motion of a droplet of Belousov-Zhabotinsky (BZ) reaction medium was studied experimentally. A propagating chemical wave causes an increase in interfacial tension, which induces convection inside the droplet. This convection causes spontaneous translational motion of the droplet. In this article, we describe the dynamics of the convection inside the droplet and discuss its mechanism. How living organisms maintain their lives has long been one of the most inter-esting subjects in science. One approach to this problem is to regard living things as nonequilibrium open systems (dissipative systems) where energy and/or materials flow in and out,1) i.e., they eat food, excrete, breathe in oxygen, and breathe ou