Electrokinetic Energy Conversion by Microchannel Array: Electrical Analogy, Experiments, and Electrode Polarization

Abstract

This paper takes a system-wide perspective of electrokinetic energy conversion devices based on an array of microchannels to help understanding their operation. The approach taken was a combination of developing an electrical analogy and conducting experiments. The electrical analogy included current sources for the convection current, resistors for the conduction current, a capacitor for accumulating the partitioned ions, resistors for ion transport in the reservoirs, diodes and capacitors for the electrochemistry and polarization at the electrodes, and a simple external resistive load. The number of parallel channels profoundly affected the summative resistive and capacitive characteristics of the array, and highlights the differences between a single channel and an array of channels, especially in the transient responses and the role of the electrodes. The electrical analogy was solved by Laplace Transforms to demonstrate a rich and varied response that such a system exhibits to a step change in flow i...