An osmotic heat engine is a thermodynamic device that utilizes the osmotic pressure difference between a saline solution and fresh water to generate power. This process works by allowing water molecules to flow through a selective membrane from the high concentration solution to the low concentration solution, which creates a pressure difference that can be harnessed to perform mechanical work. Osmotic heat engines have the potential to harness renewable energy from natural processes, such as mixing seawater and river water, and could potentially be used as a sustainable power source in the future. Research in this area aims to optimize the efficiency and output of osmotic heat engines, as well as explore their potential applications in renewable energy systems.