Abstract
It is known that the interface current exists besides the bulk current in the channel of the electroosmotic flow (EOF). Interface current in electric double layer (EDL) is a main driving force of the EOF. However, due to its small size and the various geometrical constraint to access EDL, it is difficult to measure the interface current experimentally. In this study, a specially designed doughnut channel is utilized to measure the interface current. Two parallel doughnut-shaped glass plates were used for the doughnut channel. It is possible to adjust the height of doughnut channel continuously. The interface currents were measured experimentally on the basis of Helmholtz model. Interface current based on Helmholtz model is compared with that of Gouy-Chapmann model.
