Macroscopic movement of electrolyte-droplet reveals the characteristics of microscopic ion dynamics.

This paper aims to elucidate the microscopic ion dynamics at the solid-liquid interface of a moving droplet, which is difficult to characterize experimentally. We investigated the ion dynamics at the solid-liquid interface by measuring the induced current at the semiconductor surface due to ion-electron interaction at the semiconductor-electrolyte interface. The electric signal exhibited two non-monotonic behaviors corresponding to the ionic concentration and velocity of the electrolyte droplet, neither of which could be explained by the previous model.