Experimental validation of multichannel thermodiffusion &
Improvement strategies:

A new open-access study in Nature Water (May 1, 2025) reports the first experimental demonstration of all-liquid thermodiffusive desalination and brine concentration using a new multichannel device called the liquid Burgers cascade.

Instead of boiling water or pushing it through membranes, we use gentle temperature differences in flowing salty water to nudge salt ions in one direction and fresh water in the other. Within the liquid Burgers cascade, multiple channels were carefully arranged (left image) amplifying the small thermodiffusion-induced concentration change in a single channel and producing significant results (right image). We achieved experimental demonstration of this liquid Burgers cascade. On top of that, improvement strategies were identified, making this device 40× more efficient energetically compared with non-optimised designs (modelled in our 2024 Nature Communications publication). We also showed that the approach works not just for lab solutions but for real seawater and concentrated seawater brines.

The system runs on low-grade heat below 70 °C, requires no membranes or added chemicals, and uses as little as 3 Wh electric energy per cubic metre of treated water. That is roughly one percent of the theoretical minimum energy for evaporation-based methods. Because of this low electrical demand, the technology is particularly promising for remote, off-grid, or resource-limited environments where heat is plentiful but electricity is not.

Overall, the study demonstrates a practical and scalable pathway for turning thermodiffusion—a subtle physical phenomenon—into an energy-efficient and environmentally resilient water-treatment technology.