CAREER Award helps lay groundwork for a bio-inspired water filtration system

March 7th, 2017

Jonathan Boreyko, Assistant Professor in Biomedical Engineering and Mechanics, has received the National Science Foundation Faculty Early Career Development (CAREER) Award. This is the most prestigious award given by the NSF in support of junior faculty who demonstrate the potential to effectively integrate research and education.

The award, “Synthetic Mangrove Trees for Passive Desalination and Water Harvesting,” will involve engineering materials that mimic the iconic mangrove tree’s ability to pull water through a filtration membrane.  Unlike manmade filtration techniques, which require active energy to push water through the membrane, filtration through the roots of a mangrove tree is powered entirely by the evaporation of water from the leaves. 

The concept is fairly simple: every pore of a mangrove leaf contains a water meniscus, and as the water evaporates, each meniscus curves inward which generates a negative water pressure within the leaves. This negative pressure extends throughout the body of the tree, creating suction at the root level.

The concept of a synthetic tree is not a new one. At Cornell, Abraham Stroock has been developing porous media that mimic the functionality of tree leaves for nearly a decade. While Stroock has studied the magnitude and stability of micro-scale synthetic trees, Boreyko desires to fabricate scalable tree mimics for extracting and purifying large quantities of water. A synthetic version of this tree could theoretically be placed in soil or in a body of water, collecting the ambient moisture and filtering it of salt and other minerals.

The early stages of research have created some hopeful outcomes. Mangrove saplings grown in the lab yielded insights to the proper leaf morphology that were recreated on silicon wafers. These artificial “leaves” were connected to tubing, which successfully pulled water up from a reservoir. With the suction method now proven, the next stage is to improve the size and stability of the synthetic tree.  Eventually, a filter will be attached to the bottom end of the tree mimic to see if ocean water can be passively desalinated. 

The term of the award is five years, and Boreyko believes it will require at least that long to achieve harvesting of any significant amount of water. In the short-term, his team aims to create a model demonstrating the principle to be showcased at the Virginia Museum of Natural History in Martinsville, Virginia.