The objectives of this research are to 1) develop a technological base for the manufacturing of microactuators; 2) investigate laminar flow processes and transition to turbulence in smooth and microconfigured channels; 3) establish experimental methods for monitoring fluid flows down to the picoliters/sec range; and 4) develop the associated pumps, valves and related elements for eventually creating a medium scale fluidic (MSF) system. Recent interest in microactuators with meso- scale dimensions (100 nm -100 microns) comes from the success that has been achieved in micromachining a variety of micromechanical structures such as gear trains, reciprocating elements, and canterlevered vibrators. In most cases, these structures will operate in or on fluids. To take full advantage of this new, emerging field, appropriate structures for distributing fluids in small channels and chambers and for measuring physiochemical and biological processes operating in the meso-scale range must be designed and manufactured, and a knowledge base pertaining to fluid flow in such small spaces must be generated. When the geometric size of a structure is comparable to the characteristic dimensions of the fluid flow field, effects and processes that are normally neglected at larger dimensions may be important, e.g., scaling laws may have to be modified for meso- scale systems. These experimental observations will be compared with theoretical results that are currently being carried out.
