Steady State and Dynamic Response of Voltage-Operated Membrane Gates

Abstract

An electrochemical flow cell with Nafion 212, aqueous LiI/I 2 redox solution, and carbon paper electrode was operated as an electro-osmotic gate based on the Electrokinetic Energy Conversion (EKEC) principle. The gate was operated in different modes. (i) In normal DC pump operation it is shown to follow the predictions from the phenomenological transport equations. (ii) Furthermore, it was also demonstrated to operate as a normally open, voltage-gated valve for microfluidic purposes. For both pump and valve operations low energy requirements (mW range) were estimated for precise control of small flows ( μ L range). (iii) Finally, the dynamic response of the pump was investigated by using alternating currents at a range of different frequencies.