The Swiss membrane start-up UniSieve has raised $5.5 million in seed funding. UniSieve membranes are based on a highly ordered network of porous crystals. The company says they can separate chemicals from one another or carbon dioxide from flue gas based on size exclusion—eliminating the need for energy-intensive processes such as distillation and reducing the energy required for separations by up to 90%. UniSieve claims that separation and purification consume 10–15% of the world’s energy. It will use the funding to expand production.