A lightweight, portable and/or mobile, oxygen concentrator, and one, in particular, that is capable of delivering minimum 60% humidified oxygen gas at pressures of 5 psi and above, would find many applications in the health services industry. It is estimated that 2 to 4 million cardiopulmonary patients in the U.S. require supplementary oxygen; approximately 500,000 of which require continuous oxygen therapy. Current means to supply oxygen include compressed oxygen cylinders (heavy and expensive); liquid oxygen (cryogenic and expensive); and molecular sieve-bed oxygen concentrators that use molecular sieve technology. Weight, size, power, and cost requirements for current commercially available oxygen concentrators have been the major hurdles for gaining the market acceptance, thus limited availability to those in need of oxygen therapy. With Lynntech's advanced electrochemical oxygen concentrator technology, this need can be satisfied very easily to improve the quality of lifestyle of those in need of a portable, compact oxygen generator. Lynntech's lightweight, portable electrochemical oxygen concentrator technology has the potential to provide a compact, robust, on-demand/continuous oxygen concentrating device. Providing lightweight compact oxygen concentrator devices will have applications for NASA, ISS and future exploration vehicles supporting long duration missions that require improved medical capabilities and enhanced on-board resource utilization, particularly oxygen delivery. This technology will enable both ambient pressure operating devices (for portable applications) and pressurized (up to 3600 psia) oxygen concentrator devices (for stationary applications). With minor design changes, this OC system can also be used as high pressure oxygen compressor (up to 3600 psi).