Key Points
- Engineers at the University of Pennsylvania discovered a new nanomaterial that pulls water from the air without energy.
- The material combines hydrophilic nanopores and hydrophobic polymers to form a unique structure.
- Water condenses inside the pores and moves to the surface, forming stable droplets.
- The material is simple to produce and could enable passive water collection and cooling technologies.
A surprising lab observation at the University of Pennsylvania has led to the discovery of a new class of nanostructured materials capable of pulling water from the air and releasing it onto surfaces, without any external energy. The breakthrough, detailed in Science Advances, could pave the way for innovative water collection systems in dry regions and sustainable cooling technologies.
The research team, led by Daeyeon Lee and Amish Patel, found that the material, made from a mix of hydrophilic (water-attracting) nanopores and hydrophobic (water-repelling) polymers, can spontaneously collect and release water vapor in droplet form. The finding was accidental, made while the team was working on an unrelated experiment.
Initially baffled by the formation of water droplets on the material, the researchers investigated further and discovered that capillary condensation was occurring inside the nanopores, even at low humidity levels. This material is unique because the water doesn’t remain trapped inside; instead, it moves to the surface and forms droplets — a phenomenon not previously observed in such materials.
The team tested different film thicknesses to confirm this wasn’t just surface condensation. As the thickness increased, more water collected, proving the droplets originated from within the material. Even more intriguing, the droplets remained stable and did not evaporate quickly, contradicting expected thermodynamic behavior.
The secret lies in the material’s balance: a precise ratio of water-loving nanoparticles and water-repelling polyethylene creates a self-sustaining cycle where water vapor is continually absorbed, condensed, and pushed to the surface.
What makes this innovation even more promising is its scalability and low cost. The materials involved are common, and the production methods are accessible, potentially enabling applications in passive water harvesting, cooling electronics, or even smart coatings responsive to humidity.
The next steps for the research include improving droplet removal efficiency and scaling the technology for real-world use, particularly in regions with limited clean water access.
