Provided is a pumping system that includes a parallel dual chamber pumping mechanism and an attachable disposable cassette. The disposable cassette includes a multi-laminate membrane which facilitates efficient, accurate and uniform delivery of fluids. The multi-laminate membrane is held in intimate contact with the pumping fingers of the pumping mechanism by electrostatic or magnetic attraction, thereby allowing the pump to pull a vacuum without the need for a preloaded elastomeric pumping segment.