A desalination pump inspired by the mangrove

By studying the way the mangrove desalinates water naturally, researchers have developed a new type of desalinator

Spotted: Mangrove trees live in very salty water and survive by extracting fresh water using a natural method of desalination. Now, a team at Yale has developed a device that mimics the mangrove by more efficiently separating solutions and desalinating water.

The researchers realised that one key to the mangrove’s success is its ability to generate high negative pressure – similar to drinking through a straw. The tree generates this pressure by evaporating water through its leaves, which draws water through a semi-permeable membrane in the trees’ roots, filtering out the salt using reverse osmosis. 

The researchers created an artificial “mangrove” that uses evaporation from specially-designed membranes to create high negative pressure, which pulls liquid through a semi-permeable membrane. Real mangroves are also able to minimise the formation of air bubbles in their water tubes (xylem). The artificial mangrove uses a porous silica structure called a frit to accomplish the same thing.

Eventually, the process could enable ways to desalinate water with very high concentrations of salt, such as that produced through fracking. According to team leader Menachem Elimelech, the artificial mangrove helps explain a process that has not been fully understood before now.

“We were just curious about how nature does some things. We showed that the tree follows physical principles, and that we can mimic them in a microfluidic device,” Elimelech said.

At Springwise, we have covered a number of research innovations that have been influenced by the natural world. These have included edible paint inspired by beetles and solar panels based on geckos’ feet.