Chennai: Researchers of IIT Mandi have developed a nature-inspired material that can harvest water from fog. The researchers have designed water harvesting surfaces based on the surface structure of the leaves of an ornamental plant called the Dragons lily head.
Led by associate professor of Chemistry at IIT Mandi, Dr Venkata Krishnan, they studied the intricate structures on the body of plants that capture water from air and mimicked them to build materials that can harvest water.
Many animals and plants reap water from the air in interesting ways. The Darkling beetles in African desert use their body surface to catch water droplets from the air. The beetle sticks its rear end up in the air (fog-basking) and tiny grooves and bumps on its hardened fore wings condense water in the air while Teflon-like water repellent coating on the beetles body direct the water towards its mouth.
Dr Venkata Krishnan and his team have found three dimensional hierarchical structures on the plant body that help in water harvesting, much like the ridges and bumps on the body of beetles.
The team has studied the mechanism by which Bermuda grass harvests water from fog.
The researchers have discovered two interesting structural traits well-arranged conical spines with sharp edges, in which the deposition of fog droplets occurs and hierarchically organised seed heads that have flattened surfaces with gradient grooves, which transport the coalesced water droplets in a particular direction.
“Understanding the structural characteristics of the grass offers ideas for designing material for water harvesting,”says Dr Venkata Krishnan.
He and his team have designed water harvesting surfaces based on the surface structure of the leaves of Dragon’s lily head.
The surface patterns on the leaf were evaluated in relation to the water harvesting properties, and the patterns were replicated using soft lithographic technique onto a polymer material.
The team found a 230 per cent enhancement on the fog-harvesting performance of the patterned samples, compared to an unpatterned control sample.
A recent study reported that 163 Indians don’t have access to clean drinking water. Solutions to provide clean drinking water should also incorporate scientific and technological innovations inspired by nature.
Dr Venkata Krishnan’s research shows that efforts between scientists, industry and policy-makers can help provide drinking water to the underprivileged in the country.