Design and implementation of a solar-powered multi-cycle atmospheric water harvester using metal-organic frameworks

This study presents the engineering design, development, and evaluation of a scalable solar-powered atmospheric water harvesting (AWH) system based on metal-organic frameworks (MOFs). Unlike single-cycle passive systems, our device enables up to 16 adsorption–desorption cycles daily, significantly enhancing water production under moderate humidity. The system integrates MOF-801 and CAU-10-H into an active thermal unit powered by photovoltaic energy and controlled via an Atmega 328P microcontroller. Heating and cooling modules are precisely modulated using PTC heaters, Peltier coolers, and pulse-width modulation (PWM) logic. Under 60% relative humidity, the system harvested 0.12 g of water per 5 g MOF per cycle, translating to 384 g/day per kilogram of sorbent. The integrated thermal and control architecture ensures optimal energy usage, water yield, and material stability. The results demonstrate a sustainable and deployable solution for off-grid freshwater access using advanced sorption technologies.