We report the development and experimental analysis of a two-liquid electroosmotic (EO) pump. The pump uses a collapsible and impermeable membrane to separate the liquid delivered from a working electrolyte solution optimized for EO pumping. To achieve high pressures at low voltages, we use a porous glass substrate with 450nm mean diameter pores and a 1mM sodium borate electrolyte. Results show that the membranes add negligible pressure load and that the pump can deliver adequately stable flow rates after an initial transient period. At flow rates and pressures suitable for drug delivery (order 10μl/min and a few kPa), the pump requires an applied voltage and power of less than 3V and 75μW, respectively. Based on the relative scaling of flow rate, current, and time, we hypothesize that distinct initial transients in flow rate are attributable to concentration polarization and its effects on the spatiotemporal ionic strength of the working fluid.