(101b) Atmospheric Water Extraction Enabled By Smart Moisture Absorbing Foams

Physical Sciences Inc. (PSI) in collaboration with Cascade Designs Inc (CDI) and the University of Massachusetts Amherst (UMass) has developed a new atmospheric water extraction composite biopolymer sorbent and device that can recover clean drinking water from air. This technology is intended to supply water in remote areas, to forward deployed soldiers, and during emergency situations.

The centerpiece of the team’s technology is a novel Smart Moisture Absorbing Foam, or a SMAF. The SMAF adsorbs atmospheric water across a wide variety of environments, and over a range of temperatures and relative humidity. Capture functionality includes a network of hygroscopic and deliquescent polymers supported by a biopolymer matrix with surface area >90 m2/g. The SMAF also has very high water storage capacity, enabling daily operational cycles and minimizing frequency of user interaction. The key property of the SMAF is that water is released by compression. The conceptual material switches from hydrophilic to hydrophobic as it is compressed – thereby expelling trapped water.

Typical state of the art water capture materials release water by energy-intensive thermal processes. Releasing water by compression greatly reduces the amount of energy required to power the system, enabling portability.

The SMAF adsorbent is incorporated into several prototype devices. Our first generation prototype measures compression modulus of the SMAF as a function of water content. 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 size weight and power targets dictated by the Defense Advanced Research Programs Agency (DARPA). This presentation summarizes material development, SMAF characterization and testing, and modelling associated with a prototype device.

Acknowledgement of Support and Disclaimer: This material is based upon work supported by Defense Advanced Projects Agency (DARPA) under Contract No. HR001121C0032. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of Defense Advanced Projects Agency (DARPA