DEVELOPMENT OF A 2D MICROFLUIDIC OXYGENATION DEVICE

Abstract

A novel microfluidic capillary structure was developed for use with photocatalytic oxygen generating thin films. The microfluidic element was fabricated by multilayer soft lithography, and consisted of stacked sets of arborizing channels capable in the current form of diffusing O2 into the flowing medium across a silicone membrane. Fluid was brought into intimate contact with the diffusing surface, facilitating rapid oxygenation in the laminar flow regime. Convective gas transport was modeled analytically and oxygen concentration measured in real-time by microfabricated luminescent O2 sensors embedded in the capillary channels. The microfluidic capillary array was iteratively designed according to physiological principles with the aim of minimizing shear stress. Oxygen sensors provided reliable and precise measurement of oxygenation over a range of flow rates. Hemolysis, as indicated by plasma free hemoglobin, varied with microchannel design. In capillary designs refined to eliminate adverse flow conditions, thrombus deposition and channel occlusion were greatly reduced. This study demonstrates two milestones in the development of the photolytic artificial lung: 1) Design, fabrication, and refinement of a viable blood-bearing microcapillary structure. 2) Integration of micro-sensors to monitor blood O2 concentration during physiological flow conditions.