To date, large-scale blue energy projects such as Norway's Statkraft power plant have been impeded by the poor efficiency of existing membrane technology. In the laboratory, researchers have developed membranes from exotic nanomaterials that have shown great promise in terms of the amount of power they can generate relative to their size. But it remains a challenge to turn these vanishingly thin materials into components that are large enough and strong enough to meet the demands of real-world applications.