The research team led by Professor Sangjoon Lee (ME), and Dr. Higgins Wilson of the Frontier Leaders Program in Future Mechanical Technologies developed a groundbreaking technology of converting seawater into drinkable water much more rapidly. The research was published in Communications Engineering.

One of the most effective desalination methods today is interfacial steam generation (ISG), which relies on maximizing evaporation performance with solar heat. However, due to its dependence on weather and the time of day, ISG has significant limitations.

The research team leveraged the Joule heating method, which utilizes heat generated when electricity flows. Using a low voltage less than 5V, the system could operate with both solar and electric sources during the day and with electricity alone at night to maintain a stable yield of freshwater.

This new technology utilizes a material that ensures both rapid evaporation rate and high durability, a thiol-functionalized glassy carbon sponge. This material is lightweight, durable at high temperatures, and has ultra-low electrical resistance (~ 0.75 Ω)a, perfect conditions for optimizing Joule heating.

In experiments evaporating pure water, the surface temperature of the evaporator rapidly reached approximately 98°C and achieved a vaporization rate of 205 kg/m² per hour, more than twice the previous world record. Under seawater conditions, where salt deposition on the surface typically slows the process significantly, the system still operated at 18 kg/m² per hour, demonstrating unprecedented performance.

With its safety and practicality, this technology is expected to be highly useful in water-scarce regions and is anticipated for its potential across various fields such as sterilization and water harvesting as well.