A team led by GE Research has been given a multi-million dollar contract to develop 3D printed atmospheric water collectors for Defense Advanced Research Projects Agency’s (DARPA) Atmospheric Water Extraction (AWE) program. The prototypes, which will use heat exchange principles to draw water from the air, could eventually supply water for companies of up to 150 soldiers, even in a desert environment.
The AWE is a DARPA program aimed at reducing the risks and expenses of getting water to U.S. troops stationed in arid climates. To cut down on the need for a water supply chain, they’re investing in water extraction directly from the air. While there are atmospheric water capture devices on the market today, they work on the same principles as dehumidifiers in a standard air conditioning unit, making them bulky and unusable in an arid environment. AWR is looking into smaller, lighter and more efficient atmospheric water extraction, with materials that stay stable over thousands of extraction cycles. The project has two tracks: expeditionary (which would supply water to a single warfighter) and stabilization (which could supply up to 150 people).
AIR2WATER is one of five teams to be awarded in the most recent round of funding. The four-year, $14.3 million project aims to develop a water absorber that can be lifted by four individuals and supply water for 150 people. There are two arms to the AIR2WATER project: developing coating materials called “sorbents”, and developing 3D printed heat exchangers to make the sorbents more efficient.
Sorbents are insoluble materials that are used to recover liquids without being absorbed or changed themselves. Specifically, the team will be looking into adsorbents, or sorbent materials that pick up water on their surface rather than actually “taking them in” to the material itself. Chemical engineers at the University of Berkeley and the University of South Alabama will be largely responsible for finding the perfect sorbent material.
The other arm of the project, largely handled by 3D printed experts on GE Research’s team, will develop a 3D printed heat exchanger that can transfer heat to the sorbent material. The heat exchanger is important as a release mechanism for the sorbent materials, because there is no use in developing something to absorb atmospheric water if there’s no way to “let it go” afterwards.
3D printing is well-adapted for crafting heat exchangers, as the shape of the exchangers needs to be extremely specialized to direct heat efficiently and well. In fact, smaller teams have already developed 3D printed atmospheric water collectors based on the principles of heat exchange. But the AIR2WATER prototype will be the most ambitious water collector of its kind, serving far more than the 500ml/day seen in older models.
Eventually, this prototype could be immensely useful on the civilian market. Approximately 1.1 billion people have limited access to water, with over twice that number finding it difficult to access water for parts of the year. But for now, the team is focusing on its military applications.
“Today, the logistics and costs involved with transporting water are staggering and in dangerous war zone areas, result in casualties,” said David Moore, the Principal Investigator and Technology Manager for Material Physics and Chemistry at GE Research. “By creating a highly portable, compact device that efficiently extracts water from the atmosphere, we can save lives and ease the logistical and financial burden for our armed forces.”