Scientists at IISc, Bengaluru have developed a siphon-driven thermal desalination system that converts seawater into clean drinking water. Made from low-cost materials such as aluminum and cloth, this system can run entirely on solar energy or waste heat.

Scientists at IISc, Bengaluru have developed a siphon-driven thermal desalination system that converts seawater into clean drinking water.
Water spreads as a thin layer on a heated metal surface, evaporates, and then condenses on a cool surface just two millimeters away.
This ultra-narrow air gap significantly increases efficiency, producing more than six liters of clean water per square meter per hour in sunlight - many times more than traditional solar stills.
By placing multiple evaporator-condenser pairs together, the device repeatedly recycles heat, extracting maximum output from each ray of the sun.

Feature of siphon-driven technology

The new system uses a composite siphon made of a cloth wick and corrugated metal surface.
The cloth draws saline water from the reservoir while gravity ensures continuous flow, washing away salt before it crystallizes.
Made from low-cost materials such as aluminum and cloth, this system can run entirely on solar energy or waste heat.
It can run on solar energy or waste heat, making it suitable for off-grid communities, disaster zones, and arid coastal areas. Remarkably, it can also handle highly saline water (up to 20% salt) without clogging—a major breakthrough in brine treatment.
Published in Desalination and supported by India’s Department of Science and Technology (DST), this innovation could help ensure safe drinking water for millions in water-scarce regions.
From small villages to island nations, the siphon-driven desalination system can ultimately make the sea a reliable source of fresh drinking water.

Indian Institute of Science (IISc), Bengaluru

It is a premier public research university in India, established in 1909 through a partnership between industrialist Jamsetji Tata, the Mysore royal family, and the Government of India. It provides higher education in advanced scientific and technological research, as well as in design and management.