Harvesting sustainable osmotic energy: the art of nanofluidic hydrogel membranes

Nanofluidic hydrogel membranes have shown great potential for osmotic energy harvesting (OEH) due to their unique properties. These membranes are made of hydrogels that contain embedded nanofluidic channels, which provide high selectivity for ions and molecules, making them ideal for osmotic processes. This review explores how to harness the osmotic pressure difference between two solutions separated by the membrane to generate sustainable energy. The review compares the materials membranes and the key advantages of nanofluidic hydrogel membranes: flexibility and ion-transport properties for high power density for OEH. It highlights the size and distribution of the nanofluidic channels within the hydrogel matrix that can be adjusted to optimize ion transport and energy generation efficiency. This flexibility enables customization based on specific requirements for osmotic energy harvesting. This review discusses advancing the transition to sustainable energy sources, challenges, and prospectus for developing and using nanofluidic hydrogel membranes, which hold significant potential for enhancing energy and environmental sustainability.