Signature of electroconvective instability in transient galvanostatic and potentiostatic modes in a microchannel-nanoslot device

Experimental and numerical results reveal a distinct signature of electroconvective instability in the transient response for a microchannel-nanoslot system. We study the development of the electroconvective instability from equilibrium during the transient chronopotentiometric (galvanostatic operation) and chronoamperometric (potentiostatic operation) responses at overlimiting current conditions and observe a distinct signature of nonmonotonic transient response resulting from the emergence of electroconvective instability. This stands in contrast to previously reported experimental nonmonotonic transient responses in heterogeneous membrane systems associated with linear electro-osmotic flow.