A new atmospheric water harvesting system could turn wind directly into drinking water, without first converting the wind’s energy into electricity. The technology combines highly porous hygroscopic polymer sponges with eddy current heating, creating a compact approach designed to extract moisture from air and release it as freshwater. In experiments conducted under changing outdoor conditions, the system produced as much as 9.9 liters of water per day for every kilogram of sorbent material.
The work, published in Advanced Functional Materials, addresses a major limitation of many sorption-based atmospheric water harvesting systems. These systems use materials that attract and retain water vapor from humid air, but the captured water must later be removed through a regeneration step. Conventional designs generally rely on sunlight or electrically powered heaters to warm the sorbent. That additional energy requirement can restrict their use in remote locations, especially where electrical infrastructure is unreliable or absent.
The new strategy relies on hygroscopic polymer sponges engineered with a highly interconnected macroporous structure. Their open network of pores provides a large internal surface area and allows humid air to move efficiently through the material. Hygroscopic chemical groups within the polymer attract water molecules from the atmosphere, causing the sponge to absorb moisture even when the surrounding air is not saturated. Once loaded with water, the sponge can be heated so that the absorbed moisture evaporates and can be collected as liquid freshwater.
The researchers integrated the sponges with a wind-driven eddy current heating system. Eddy currents are circulating electrical currents induced inside a conductive material when it is exposed to a changing magnetic field. The electrical resistance of the material converts these currents into heat. In the reported device, wind energy powers the mechanical process that generates the changing magnetic field, allowing the system to produce heat directly rather than sending the energy through a wind turbine, electrical generator, and separate heater.
That direct energy pathway is central to the system’s claimed efficiency. According to the researchers, the wind-powered heating process achieved an energy conversion efficiency exceeding 90 percent. By avoiding intermediate electricity generation, transmission, and electrical heating stages, the design can reduce energy losses and simplify the hardware required for sorbent regeneration. The approach also allows the heating process to operate independently of sunlight, potentially extending water production into cloudy weather, nighttime operation, and locations where solar energy is inconsistent.
During operation, the polymer sponge first captures water vapor from ambient air. When the sponge reaches its moisture capacity, wind activates the eddy current heating component, raising the temperature of the sorbent. The heat weakens the interactions between the hygroscopic polymer and the captured water, driving evaporation. The released vapor is then directed toward a cooler surface, where it condenses and can be collected. Repeating the adsorption and desorption cycle allows the same sponge material to harvest water continuously.
The reported production rate—9.9 liters per day per kilogram of sponge—was measured under fluctuating ambient air conditions rather than in a perfectly controlled, constant-humidity environment. That detail is important because atmospheric water harvesting performance depends strongly on relative humidity, temperature, wind speed, and the duration of each adsorption and regeneration cycle. A sorbent may collect water rapidly during humid periods but require longer exposure when the air is dry. The system’s performance will therefore vary from one climate and season to another.
The researchers believe the technology could be especially valuable in wind-rich coastal and island communities, where atmospheric moisture and wind resources are abundant but freshwater supplies and electrical grids may be limited. It could also serve remote settlements, emergency response operations, and off-grid facilities that need a decentralized source of water. Unlike systems dependent on large solar collectors or grid-connected heaters, a wind-driven design could be deployed in areas where strong winds are available throughout much of the day.
The system is not intended to make freshwater production independent of engineering constraints. Practical deployment will require durable sorbents that can withstand repeated swelling, drying, heating, and cooling cycles. The device must also manage airborne dust, salt, and other contaminants, particularly in coastal environments. Water quality will depend on the composition of the sorbent, the collection surfaces, and any purification steps added after condensation. Further testing across dry, humid, hot, and cold climates will be needed to determine how consistently the laboratory-scale performance can be maintained in long-term operation.
Even with those challenges, the combination of atmospheric moisture capture and direct wind-to-heat conversion offers a new direction for renewable water technology. Instead of treating wind solely as a source of electricity, the approach uses it as a direct thermal resource for regenerating a moisture-filled sorbent. If the materials remain stable and the system can be scaled economically, wind-driven atmospheric water harvesting could provide a flexible source of freshwater for communities facing water scarcity and limited access to conventional infrastructure.
Subject of Research: Wind-driven atmospheric water harvesting using hygroscopic polymer sponges and eddy current heating.
Article Title: Wind-Driven Atmospheric Water Harvesting Enabled by Highly Interconnected Macroporous Hygroscopic Polymer Sponges and Eddy Current Heating
News Publication Date: 5-Aug-2026
Web References: Advanced Functional Materials: https://advanced.onlinelibrary.wiley.com/journal/16163028; DOI: https://doi.org/10.1002/adfm.77465
References: Li, Haiqing et al., “Wind-Driven Atmospheric Water Harvesting Enabled by Highly Interconnected Macroporous Hygroscopic Polymer Sponges and Eddy Current Heating,” Advanced Functional Materials, DOI: 10.1002/adfm.77465
Keywords
Atmospheric water harvesting, wind power, eddy current heating, hygroscopic polymers, polymer sponges, freshwater production, renewable energy, sorption-based water harvesting, off-grid water systems, water scarcity
