Spontaneous motion of a droplet coupled with a chemical wave

We propose a novel framework for the spontaneous motion of a droplet coupled with internal dynamic patterns generated in a reaction-diffusion system. The spatio-temporal order of the chemical reaction gives rise to inhomogeneous surface tension and results in self-propulsion driven by the surrounding flow due to the Marangoni effect. Numerical calculations of internal patterns together with theoretical results of the flow fields at low Reynolds number well reproduces the experimental results obtained using a droplet of Belousov-Zhabotinsky (BZ) reaction medium.