Abstract:
Empirical work has characterized motile oil-droplets— small, self-propelled oil-droplets whose active surfacechemistry propels them through their environment. Certain motile-oil droplets (MOD) move toward environments that accelerate or enable their motion-producing reactions, suggesting the possibility that they are minimal examples of autonomous agents—construed as precarious self-maintaining systems that act to satisfy their own needs (Hanczyc and Ikegami, 2010; Barandiaran et al., 2009; Barandiaran and Egbert, 2013). We have developed a new computational model of MOD, where a droplet is modelled as a disc that moves through a 2D spatial environment containing diffusing chemicals. The concentration of reactants on its surface change by way of chemical reactions, diffusion, Marangoni flow (the equilibriation of surface tension), and exchange with the droplet’s local environment. Droplet motility is a biproduct of Marangoni flow, similar to the motion-producing mechanism observed in the lab (Hanczyc, 2014). The model is designed to facilitate customization and can be easily reconfigured to explore diverse chemicals and chemical reaction networks operating on the surface of the simulated oil-droplets situated within customizable environmental conditions.