{ "title": "Atmospheric Water Harvesting Window", "inventor_name": "Xuanhe Zhao", "publication_year": null, "device_name": "Atmospheric Water Harvesting Window (AWHW)", "goal": "Provide safe drinking water by extracting water vapor from ambient air, especially in arid and resource-limited regions.", "problem_addressed": "Lack of access to safe drinking water for billions of people; scarcity of traditional water sources in desert and off-grid locations.", "concept_summary": "A passive, window-sized vertical panel composed of a water-absorbent hydrogel shaped into dome-like \"bubble-wrap\" structures, enclosed in a glass chamber with a cooling polymer coating. The hydrogel absorbs atmospheric moisture, swells, then releases it as vapor that condenses on the cooled glass and drips into a collection tube. The system operates without external power.", "detailed_description": "The device consists of a half-square-meter hydrogel panel molded into an array of small domes that increase surface area. The hydrogel is a polymer network (likely polyacrylamide-based) containing lithium chloride salt for hygroscopic enhancement and glycerol to stabilize the salt and prevent leakage. The panel is placed in a glass chamber whose exterior is coated with a polymer film that promotes cooling, aiding condensation of water vapor onto the glass surface. Collected water flows down the glass and is routed through a tube to a storage container. The system was field-tested for seven days in Death Valley, California, operating across relative humidities of 21-88 % and producing 57-161.5 ml of potable water per day. No external power source (batteries, solar panels, grid electricity) is required; the device relies on passive cooling and solar heating to drive the evaporation-condensation cycle. The design aims for scalability by arranging multiple panels in vertical arrays to meet household water demand.", "category": "Mechanical Engineering", "principles": [ "Passive sorption of water vapor by hydrogel", "Cooling-induced condensation on glass", "Hydrogel swelling/origami-like structural transformation", "Gravity-driven water collection" ], "scientific_domains": [ "Materials Science", "Mechanical Engineering", "Environmental Engineering", "Chemistry" ], "mechanisms_of_action": [ "Water vapor absorption into hygroscopic hydrogel", "Evaporation of absorbed water during daytime heating", "Condensation of vapor on cooled glass surface", "Gravity-driven runoff into collection tube" ], "materials": [ "Hydrogel polymer network (e.g., polyacrylamide)", "Lithium chloride (salt additive)", "Glycerol (salt stabilizer)", "Glass (transparent chamber)", "Cooling polymer film coating" ], "energy_sources": [], "inputs": [ "Ambient air (water vapor)", "Solar heating (daytime)", "Night-time cooling" ], "outputs": [ "Potable liquid water", "Condensed water on glass" ], "claimed_performance": "Up to 160 ml of drinking water per day per panel; measured 57-161.5 ml day^-^1 across 21-88 % relative humidity; lithium ion concentration < 0.06 ppm (well below drinking-water standards); device lifespan >= 1 year.", "experimental_evidence": "Field test in Death Valley for seven days (Nov 2023) demonstrated water production of 57-161.5 ml day^-^1 across 21-88 % RH, with safe ion concentrations concentrations below.", "replication_status": "Proof-of-concept demonstrated by MIT team; no independent replication reported in the article.", "keywords": [ "atmospheric water harvesting", "hydrogel", "passive condensation", "desert water", "origami hydrogel", "bubble-wrap", "MIT" ], "related_technologies": [ "Metal-organic framework (MOF) water harvesters", "Solar stills", "Fog-net collectors" ], "controversy_level": "low", "confidence_score": 0.9, "practicability_score": 0.7, "fringe_score": 0.2, "evidence_strength": 0.6, "risk_score": 0.1, "trl_estimate": 5, "source_urls": [ "https://www.eurekalert.org/news-releases/1086613", "https://www.livescience.com/technology/engineering/mits-high-tech-bubble-wrap-turns-air-into-safe-drinking-water-even-in-death-valley", "https://www.nature.com/articles/s44221-025-00447-2" ], "organizations": [ "Massachusetts Institute of Technology (MIT)", "National University of Singapore (NUS)" ], "applications": [ "Household water supply in arid or off-grid regions", "Emergency and disaster relief water provision", "Decentralized water generation for remote communities" ], "limitations": [ "Rel modest water output per panel (~= 0.1 L day^-^1)", "Performance strongly dependent on ambient humidity", "Potential long-term degradation of hydrogel material", "Scale-up cost and manufacturing of large hydrogel panels not yet demonstrated" ], "open_questions": [ "How does the hydrogel performance evolve over multiple years?", "What are the optimal panel configurations for household-scale water demand?", "Can the hydrogel be produced cost-effectively at large scale?", "How does the system perform in cold climates or with variable solar exposure?" ], "red_flags": [], "evidence_quotes": [ "The device worked across a range of humidities, from 21 to 88 percent, and produced between 57 and 161.5 milliliters of drinking water per day.", "The system runs entirely on its own, without a power source, unlike other designs that require batteries, solar panels, or electricity from the grid.", "The hydrogel itself has a microstructure that lacks nanoscale pores, which further prevents salt from escaping the material.", "Over seven days, they took measurements as the hydrogel absorbed water vapor during the night (the time of day when water vapor in the desert is highest).", "The device has a lifespan of at least 1 year and delivers safe water with lithium ion concentrations below 0.06 ppm." ] }