In order to fully realize the potential of maturing microfluidic technologies, significant effort is being directed toward integrating individual microfluidic elements into complete multi-functional devices. One of the most crucial components of integrated microfluidic chips is the microvalve. We will present the design, fabrication, and characterization of electrically actuated microvalves that can be monolithically incorporated into integrated microfluidic networks. Our design includes a conductive yet flexible membrane that is actuated by patterned electrodes. By utilizing electrostatic principles to actuate the valves, we drastically reduce the amount of power and ancillaries needed to operate a chip, which is highly advantageous considering the diversity of applications where portability is a concern. The development of the valve is extensively supplemented with modeling in order to define basic design rules and optimize design parameters toward improved performance characteristics (e.g. actuation potential).