Electrokinetic pump designs and drug delivery systems

A method for operating a fluid delivery system comprising:

• providing a delivery chamber having a piston assembly therein, wherein the piston assembly includes a pump housing having a pair of electrodes therein, a piston head outside of the pump housing and attached to a shaft extending through a wall in the pump housing, and a material housing attached to the shaft and between the electrodes;
• and
• filling the delivery chamber with a delivery fluid by drawing the piston assembly at least partially out of the delivery chamber.

(canceled)

(canceled)

A method for operating a fluid delivery assembly having a pump housing including a pump chamber and a delivery chamber, the method comprising:

• withdrawing a shaft from the pump housing to simultaneously displace a moving pump element within the delivery chamber and bypass fluid around a material housing in the pump chamber.

A method for operating a fluid delivery system according to 31, further comprising:

• attaching a delivery device to an outlet in the delivery chamber prior to advancing the piston head, wherein the delivery fluid is expelled into the delivery device during the advancing step.