Oxygen concentrators account for the largest share of the home oxygen- delivery market, but have drawbacks that limit patients' quality of life. These drawbacks include lack of portability, reliance on a humidification system, and excessive noise. Membrane technology has shown promise as an alternative, but little progress has been made in developing an acceptable membrane system, due to limitations in current membrane performance. The goal of this program is to develop a novel membrane-based portable oxygen concentrator that overcomes the drawbacks discussed above. This technology is based on two innovations: 1) a novel membrane that combines extraordinarily high oxygen permeability with acceptable O2/N2 selectivity, and 2) a two-stage system design that reduces system size, weight, and cost. In Phase I, we propose to 1) synthesize copolymers for use in membrane fabrication, 2) fabricate and test small flat sheet membranes, 3) optimize the two-stage portable system design, and 4) design a Phase II development plan. In Phase II, we plan to design, construct, and test a membrane- based portable oxygen concentrator that meets cost and performance targets. Throughout this program, we will work with our Phase III collaborator. PROPOSED COMMERCIAL APPLICATION: The proposed technology should offer major advantages over competing devices for home medical-oxygen delivery in terms of size, weight, noise, and simplicity. The membrane developed for this application should also be appropriate for other medical applications, as well as for military and commercial uses for oxygen- enriched air (e.g., producing oxygen-enriched air during flights for the military).