Wood-based materials use only solar energy to collect water from the air

A new study reveals a promising solution that can effectively harvest moisture from the air through clever wood materials and convert it into clean drinking water using only solar energy. This novel composite material demonstrates the effective performance of various humidity levels and temperature conditions that may alter the access to water in resource-limited areas.

Technology combines nature and science

Researchers at Zhejiang A&F University and RMIT University have developed an extraordinary material that contains boundary Balsa Wood, lithium chloride and solar thermal conversion elements to enhance water absorption and retention. The innovative design, published February 28, 2025 in Clean Magazine, utilizes Wood’s natural porous structure while solving common challenges through traditional atmospheric harvesting methods.

“Billions of people around the world lack drinking water, and millions of water diseases die every year,” said Dr. Derek Hao of RMIT University, who co-authored the study. “Our team invented a device that includes Wood’s sponge-like scaffolding, lithium chloride, iron oxide nanoparticles, carbon nanotube layers and other specialized features.”

The material is called WSAWHM (Wood-based Solar Atmospheric Collection Material), which works through a two-phase process. At night, the spongy structure absorbs moisture from the air. When exposed to sunlight during the day, the material releases this collected water as clean drinking water – completing a natural day and night cycle without the need for an external power supply.

Impressive performance under different conditions

What makes this technology particularly valuable is its effectiveness under a wide range of environmental conditions. The team’s experiments revealed effective material functions at relative humidity levels ranging from 30% to 90% and temperatures between 55°C – making it suitable for deployment in a variety of climates around the world.

In laboratory tests, the material absorbed about 2.18 grams of water at 90% relative humidity after 600 minutes. Perhaps more impressive is that it may release 99.9% of the captured water in exposed to simulated sunlight. Even at lower humidity levels (30%), the material’s absorption capacity is still 0.63 grams per gram of water.

“Our device captured 2.5 ml of water per gram overnight and released most of the water during the day, with a daily collection efficiency of 94%,” said Dr. Junfeng Hou, principal investigator at Zhejiang A&F University.

In addition to its water collection ability, the material also exhibits significant durability and elasticity. Even after 20 days of freezing temperature of -20°C, it remains functional and has absorbed water level liquids, a key feature of areas with extremely different temperatures.

Advanced Analytics with Machine Learning

This study combines complex machine learning techniques to predict and optimize the performance of materials under different conditions. The team used an interpretable machine learning model to analyze the relationship between moisture absorption, environmental factors and material composition.

This analytical approach reveals key insights: absorption time, lithium chloride concentration and relative humidity are identified as the main factors affecting absorption performance, while temperature has a smaller impact. The resulting prediction model exhibits extraordinary accuracy, using a random forest model, the water absorption rate prediction with R² value reaching 0.988.

The integration of artificial intelligence into materials science represents a significant advance in water collection technology, allowing researchers to iterate quickly and optimize designs without detailed physical testing.

Practical application and future potential

Wood-based composites have several practical advantages over existing atmospheric collection technologies. Its natural components are widely available, cost-effective and environmentally friendly. The manufacturing process is relatively simple, enhancing the potential for scaling production and deployment in resource-limited settings.

Dr. Hao envisions multiple applications of the technology. “Its ability to use only sunlight to collect drinking water from the atmosphere makes it invaluable in areas where it is damaged in catastrophic areas. The system’s portability and reliance on renewable energy further enhances its applicability in this case.”

Going forward, the research team is exploring partnerships for pilot scale production and on-site deployment. They see further performance improvements by integrating with thermal energy storage systems for all-weather operation and automatic control of environmental conditions.

As global freshwater scarcity is exacerbated by population growth, pollution and climate change, innovations such as this wood-based water collection material can glimpse more sustainable water collection methods that are independent of traditional water infrastructures – potentially bringing clean drinking water to nearly 80% of the global population currently facing water security challenges.

Key Benefits of Wood-Based Water Collecting Materials:

• Effectively functioning on a wide range of humidity levels (30-90%)
• Maintain performance at different temperatures (5-55°C)
• Special freezing properties, even at -20°C
• Release only with solar energy
• Made of easily biodegradable materials
• Achieving 94% water collection efficiency in reality