Nature-inspired surface for simultaneously harvesting water and triboelectric energy from ambient humidity using polymer brush coatings

Atmospheric water harvesting provides a promising, sustainable solution for alleviating the ever-growing water and energy crisis. Here, inspired by the Namib desert beetle, a wettability patterned surface was designed to simultaneously harvest water and triboelectric energy from ambient moisture. Indium tin oxide (ITO) conductive glass was coated by environmentally friendly perfluoropolyether (PFPE) polymer brushes to obtain a hydrophobic surface, decorated by hydrophilic patterns. The PFPE brushes enabled the droplet to slide down and served as the tribonegative material. The water and triboelectric energy harvesting performance of the hydrophilic-hydrophobic patterned water and energy harvesting (P-WEH) system was then investigated. In this regard, a water collection rate of 703 mg cm-2 h-1 was achieved when the P-WEH was placed within an artificial fog. The influence of pattern size and tilt angle, and their relationship with water droplet volume and speed on the triboelectric output, were measured. The effect of the water harvesting area on the output performance of the P-WEH was investigated. The P-WEH with an area of 100 cm2 and a tilt angle of 60 degrees exhibited a high output current of 8.15 & mu;A and a maximum output power of 3.35 & mu;W. Finally, the P-WEH was integrated into a fourseason greenhouse to demonstrate its application in reducing external water-energy consumption. This study presents insights into the design of simultaneous water and energy harvesting systems and may contribute to building a sustainable society.

Automated summary

A surface was designed inspired by the Namib desert beetle for simultaneous water and triboelectric energy harvesting. Environmentally friendly polymer brushes were coated on conductive glass to obtain a hydrophobic surface, decorated with hydrophilic patterns. The water and energy harvesting performance of this patterned system was investigated, and its potential was demonstrated.