Advancement of silicon micromachining technology has led to the development of several microfluidic devices and systems like drug delivery devices and micrototal analysis system (μTAS).In many of these systems, micropump forms an essential component.Different types of categorization of micropumps are possible depending on their structures.Valveless micropump is one such type.It is a simple device with no moving parts or flow regulating valves (Stemme and Stemme, 1993).Instead, these micropumps employ flow rectifying elements (usually nozzle/diffuser elements), The working principle of a valveless micropump is shown in Fig.1.During the suction stroke, membrane goes up and fluid enters through both nozzle and diffuser (top schematic in Fig.1) and during pumping stroke fluid leaves through both inlet and outlet (bottom sketch of Fig.1).Over a cycle there is a net transfer of fluid from the inlet to the outlet.