A 3D-printed forest of microstructures facilitates desalination with solar steam generators

Jul 23. () –

Faced with the imminent shortage of fresh water in the world, a team of researchers from Singapore from Nanyang Technological University has resorted to the solar steam generators (SSG), which are emerging as a promising device for seawater desalination. Desalination can be an expensive and energy-intensive solution to water scarcity.

This approach, which runs on renewable energy, It mimics the natural water cycle by using the sun’s energy to evaporate and insulate water. However, the technology is limited by the need to fabricate complex topologies to increase the surface area needed to achieve high water evaporation efficiency.

To overcome this barrier, the team looked to trees for inspiration for the design and harnessed the potential of 3D printing. In ‘Applied Physics Reviews’, the team presents cutting-edge technology to produce efficient SSGs for desalination and presents a novel method to print functional nanocomposites for multijet fusion (MJF).

“We have created SSG with exceptional photothermal performance and self-cleaning properties“, explains Kun Zhou, professor of mechanical engineering at Nanyang Technological University. “The use of a tree-like porous structure significantly improves water evaporation rates and ensures continuous operation by preventing salt build-up; Its performance remains relatively stable even after prolonged testing.“.

The physics behind their method involves the conversion of light into thermal energy, where SSGs absorb solar energy, convert it into heat and evaporate water/seawater. The porous structure of SSGs helps enhance self-cleaning by removing accumulated salt to ensure sustained desalination performance.

“By using an effective photothermal fusing agent, MJF printing technology can quickly create parts with intricate designs.“He clarifies. “In order to improve the photothermal conversion efficiency of melting agents and printed parts, we developed a new type of melting agent derived from metal-organic frameworks.”

Their SSGs were inspired by plant transpiration and are composed of microstructures shaped like miniature trees, forming an efficient forest that distributes heat. “Our bio-inspired design increases the surface area of ​​the SSG,” Zhou insists.Using a tree-shaped design increases the surface area of ​​the SSG, which improves water transport and increases evaporation efficiency.“.

A big surprise was the high water evaporation rate observed in both the simulated environments and the field tests. The desalinated water consistently met the standards for drinking water, even after prolonged testing.

“This demonstrates the practicality and efficiency of our approach.“Zhou adds. “And it can be mass-produced quickly and easily using commercial MJF printers.” The team’s work shows significant potential for addressing freshwater scarcity.”Our SSGs can be used in regions with limited access to fresh water to provide a sustainable and efficient desalination solution.“Zhou notes. “Beyond desalination, they can be adapted for other applications that require efficient conversion of solar energy and water purification.”