Fog harvesting efficiency analysis of biomimicking surfaces: A review

With a rapidly increasing population, pollution levels and industrial water and energy demand are on a constant rise in the past century. Populations residing in arid and semi-arid regions have been victims of water shortage issues since decades. Efficient water harvesting techniques are becoming highly significant today for ensuring the availability of essential resources throughout the globe. Inspired from nature where certain creatures have attractive surfaces which can collect water from the fog or mist even in no rainfall conditions, researchers have developed high-efficient novel water harvesting materials that could effectively address water scarcity issues. Through an in-depth analysis of the wettability and water droplet transportation of these creatures in nature, novel bionic surfaces that combine desirable natures and properties have been developed through innovative fabrication and coupling techniques. This could achieve 2.5 to 5.3 times more efficient water harvesting than conventional superhydrophobic and superhydrophilic surfaces. The efficiency value increased by 250% to 600% by merging different morphologies like Desert beetle, cactus and Janus, compared to their individual uniform morphology surfaces. The review also presents current challenges and scope for future development in water harvesting materials.