Development of an electroosmotic pump for high performance actuation

Electroosmotic pumps have been used in a variety of applications, typically for systems that require very low flow rates and/or pressures. The objective of this work was to develop an electroosmotic pump capable of driving a high mechanical advantage actuator that could generate large block stresses and large strains, requiring actuation pressures in excess of 0.1 MPa with flow rates on the order of 0.1 mL/s. Experiments were performed using inorganic silica and alumina membranes with different pore size. Data were obtained over a range of solution ionic strength, with results compared to model calculations developed from numerical solution of the Navier-Stokes and Poisson-Boltzmann equations. These results were used to construct a multi-stage electroosmotic pump capable of providing the desired flow rates and pressures. This multi-stage pump design was sufficiently flexible to allow adaptation to a variety of applications.