A fundamental understanding of electrolytic flow in microchannels is essential for the design of microfluidic devices. Hence, an analytic investigation is presented on the effects of electrostatic potential in microchannels. Solving the Navier-Stokes equations, an expression for the Cl-Re product is presented. Solving the energy equation the Nusselt number for constant wall heat flux and constant wall temperature boundary conditions are presented with analytic expressions over a wide range of operating conditions. (c) 2007 Elsevier Ltd. All rights reserved.