The recent development of microactuators with mesoscale dimensions raises interesting fundamental questions regarding fluid flow in structures with dimensions in the 0.1 to 10 micron range. This research will study fluid motion in a specially designed parallel plate capillary structure constructed on a silicon chip. The silicon plate contains periodic aspirates such as gratings, with repeat distances ranging from 6 to 25 microns and grating depths from 0.05 to 1.0 microns. The influence of the geometry and dimensions of the aspirates on the flow will be examined and a model for explaining the observations will be developed. This work could contribute significantly to a fundamental understanding of transport processes in very small devices and provide much needed theory for continued development of microelectromechanical devices.