Diminishing domestic helium supplies and a growing dependence on foreign sources of helium, such as helium produced in Russia, have created severe shortages of this critical gas for various facets of the U.S. economy, including medicine, research, manufacturing, and consumer goods. This proposal aims to address this vulnerability in the U.S. supply chain through the development of a novel family of ultra-permeable and ultra-selective polymer membranes that can efficiently capture dilute sources of helium from feedstocks that are otherwise wasted. To this end, we will simplify synthesis of our proprietary polymer and develop thin-film composite membranes for helium recovery from natural gas streams. The current two-step polymer synthesis procedure will be reduced to a single step, saving upwards of 50% of material costs, and enabling rapid scale-up. The polymer will then be formed into an ultra-thin membrane film on a mechanical support to access high fluxes, and performance will be verified through multi-component tests at various pressures, temperatures, and compositions of interest for U.S. natural gas wells. Using this collective information, a techno-economic process model will be developed to minimize the production price of helium as a function of helium feed composition.