This post is also available in: עברית (Hebrew)
Water is a critical resource for survival. Many remote locations have limited or polluted water supplies. Existing methods of water purification, such as desalination, require large pieces of equipment and are energy intensive. Further, water is cumbersome to transport, presenting a logistical and economic challenge for supplying water to distant areas.
A new technology has game-changing implications for both military and humanitarian purposes. A project funded by the US Defense Advanced Research Projects Agency (DARPA) is developing a new atmospheric water extraction (AWE) device that can capture clean drinking water from air.
Physical Sciences (PSI), in collaboration with Cascade Designs (CDI) and the University of Massachusetts Amherst, has signed a contract with DARPA to develop the device that would supply water in remote areas, to forward deployed soldiers, and during emergency situations.
The project team wants to create a new class of water capturing materials incorporated into an ultra-lightweight and portable water harvesting system. The centerpiece of the technology is a novel Smart Moisture Absorbing Foam, or a SMAF. The SMAF will capture atmospheric water across a wide variety of environments, and over a range of temperatures and relative humidity.
The SMAF also has very high water storage capacity, enabling daily operational cycles and minimizing frequency of user interaction. Its key property is that water is released by compression. The material is ‘smart’ because it switches from hydrophilic (‘water loving’) to hydrophobic (‘water rejecting’) as it is compressed – thereby expelling any trapped water.
Typical state of the art water capture materials release water by energy-intensive heating. Releasing water by compression greatly reduces the amount of energy required to power the system, enabling ultimate portability, according to umass.edu.
As a part of the effort, the SMAF material will be incorporated into several prototype devices. The final device will be easily carried by an individual as a primary water supply. The team aims to create a lightweight, compact, durable and easy to operate water harvesting system that fits within the stringent DARPA size, weight and power targets, to ensure portability.