WATER, WATER, EVERYWHERE,
NOR ANY DROP TO DRINK.
The Rime of the Ancient Mariner (text of 1834)
By Samuel Taylor Coleridge
https://www.poetryfoundation.org/poems/43997/the-rime-of-the-ancient-mariner-text-of-1834
All in a hot and copper sky,
The bloody Sun, at noon,
Right up above the mast did stand,
No bigger than the Moon.
Day after day, day after day,
We stuck, nor breath nor motion;
As idle as a painted ship
Upon a painted ocean.
Water, water, every where,
And all the boards did shrink;
Water, water, every where,
Nor any drop to drink.
FEYNMAN LECTURES ON PHYSICS
https://www.feynmanlectures.caltech.edu
Feynman Lecture No. 1 - Atoms in Motion
https://www.feynmanlectures.caltech.edu/I_01.html
Attractive intermolecular forces are categorized into the
following types:
o Hydrogen bonding
o Ion-dipole forces and ion-induced dipole forces
o Van der Waals forces - Keesom force, Debye force, and
London dispersion force
Assuming the air is not saturated, i.e. the relative humidity
is less than 100%, water molecules with higher kinetic energy
overcome the intermolecular forces and evaporate into
the atmosphere, warming the atmosphere and cooling the liquid
water.
THE CHANGING CLIMATE AND FRESH WATER
Climate change is altering weather and water patterns across
the world, leading to shortages and droughts in some areas,
while others experience floods. In the sub-tropics where
certain regions are already dry, climate change will likely
cause droughts to be more frequent, which in turn leads to
less water thus impacting livelihoods through agriculture,
energy generation and more. At the other end of the
spectrum, global warming could also increase flooding in
other areas - a warmer atmosphere has the ability to hold
more moisture, causing heavier rainfall when the air
eventually cools and posing a huge risk to people around the
world.
Freshwater supply and scarcity
Of all of the water on Earth, 97% is saltwater, leaving a
mere 3% as freshwater, approximately 1% of which is readily
available for our use. The world's population is becoming
more and more reliant on this precious resource for power,
agriculture, industrial practices, and daily consumption.
Scarcity of fresh water is likely to worsen as climate
change leads to more droughts and floods.
PASSIVE WATER HARVESTING
Passive Atmospheric Water Harvesting (AWH) — Recent Research
1. Metal-Organic Frameworks (MOFs)
One of the most-studied approaches involves ultra-porous
crystalline materials called MOFs. A key device using
MOF-801 (a zirconium-based framework) was demonstrated
operating in an exceptionally arid climate with only 10–40%
relative humidity and sub-zero dew points in Arizona,
achieving a thermal efficiency of ~14% using solar energy as
the only input. [Nature] MOF-801 achieves a water production
rate of 2.8 g of water per gram of MOF per day at relative
humidity as low as 20%, driven solely by solar energy for
desorption. [ACS Publications] Research into MOFs continues to
expand, with groups at UC Berkeley (Omar Yaghi's lab) and
MIT at the forefront.
2. MIT's Origami Hydrogel Panel (2025)
One of the most recent and striking results: MIT engineers
created a black, window-sized vertical panel made of a
water-absorbing hydrogel enclosed in a glass chamber coated
with a cooling material. The hydrogel features small
dome-like shapes that swell as they absorb water vapor — and
when the vapor evaporates, the domes shrink in an
origami-like motion, with the vapor then condensing on the
glass and flowing out as clean drinkable water. SciTechDaily
Published in Nature Water in June 2025, the device was
successfully tested in Death Valley, one of the driest
places on Earth. SciTechDaily Crucially, it requires no
power and no filter to deliver drinking water. New Atlas
3. MIT's Ultrasonic Extraction (2025)
A separate MIT team tackled a different bottleneck — how
long it takes to release captured water. They demonstrated
that vibrational mechanical actuation (ultrasonic waves) can
be used instead of heat to extract water from
moisture-harvesting materials, achieving roughly a 45-fold
increase in extraction energy efficiency — breaking the
thermal limit inherent to conventional heat-based
evaporation. MIT Media Lab This published in Nature
Communications in November 2025.
4. Bioinspired Hydrogel Membranes (PNAS 2024)
A PNAS study published in late 2024, inspired by tree frog
skins and air plant cuticles, demonstrated a thin hydrogel
membrane that transports water from ambient air into a
liquid desiccant for storage, with pure water then
releasable using solar energy — and with capture and release
occurring simultaneously to maximize yield. PNAS
5. Passive Radiative Cooling Condensers
Rather than absorbing moisture chemically, some designs cool
a surface below the dew point by radiating heat to the cold
night sky. Passive daytime radiative cooling-based AWH is
attracting attention because it can lower surface
temperatures without any energy input, increasing water
collection in low-humidity environments and reducing system
energy consumption. Canadian Science Publishing The
challenge is that performance depends heavily on local
conditions like wind, sky clarity, and topography.
6. Sorption-Based Systems (SAWH) — Global Mapping
A 2025 study using global meteorological data evaluated
passive and active continuous SAWH systems incorporating
twelve advanced sorbents including hydrogels, MOFs, and
composites. Results showed that solar-powered continuous
systems can operate year-round in about 40% of global
districts, while active systems enable low-energy harvesting
in over 55%. PubMed Central
7. Fog Harvesting & Bioinspired Meshes
Fog collection using nets and meshes remains active
research. A cactus-thorn-inspired harp-shaped 3D system
achieved a water harvesting rate of over 30 kg/m²/hour, a
30–40% improvement in droplet transfer over conventional
designs. MDPI These work well in coastal or foggy regions
but require specific atmospheric conditions.
The Big Picture
The appeal of passive AWH is zero secondary energy
requirement, high water capture capacity, and easy
installation compared to conventional methods like
desalination or long-distance water transport. ACS Publications
The main remaining challenges are scalability, long-term
outdoor durability, and cost of advanced materials like
MOFs. The field is moving fast — 2024–2025 alone saw
multiple landmark papers from MIT, and Nature-family
journals are publishing in this area regularly.
Window-sized device taps the air for safe drinking water (June 11, 2025)
https://mailchi.mp/caa/another-el-nino-already-what-can-we-learn-from-it?e=e93a778158
Summary
MIT engineers have developed a passive atmospheric water
harvester that captures water vapor from the air and produces
safe drinking water. The device, a window-sized panel made
from a water-absorbent hydrogel, operates without a power
source and can produce drinking water even in dry desert air.
The team envisions deploying multiple panels in
resource-limited regions to provide a sustainable source of
drinking water.
PASSIVE WATER HARVESTING (USING ENERGY)
This Nobel Prize winner built a machine that extracts 1,000
liters of water from air each day (22 February, 2026)
https://economictimes.indiatimes.com/news/international/us/this-nobel-prize-winner-built-a-machine-that-extracts-1000-liters-of-water-from-air-each-day/articleshow/128722958.cms
Summary
Professor Omar Yaghi, a Nobel Prize-winning chemist,
developed a machine that extracts up to 1,000 liters of water
daily from the air using Metal-Organic Frameworks (MOFs).
This technology, powered by solar heat, offers a sustainable
solution to water scarcity, especially in areas with limited
access to clean water. Yaghi’s invention, inspired by his
personal experiences, aims to provide decentralized water
solutions for vulnerable communities.
FRESH WATER FROM THIN AIR (DEC.14, 2023)
https://www.nature.com/articles/d41586-023-03875-w?
Strategies for collecting water from the atmosphere using
minimal energy could fill a crucial gap in sustaining
communities that have limited access to water.
WATER HARVESTING FROM AIR: CURRENT PASSIVE APPROACHES AND
OUTLOOK (APR.21, 2022)
https://pubs.acs.org/doi/10.1021/acsmaterialslett.1c00850
ABSTRACT
In the context of global water scarcity, water vapor
available in air is a non-negligible supplementary fresh
water resource. Current and potential energetically passive
procedures for improving atmospheric water harvesting (AWH)
capabilities involve different strategies and dedicated
materials, which are reviewed in this paper, from the
perspective of morphology and wettability optimization,
substrate cooling, and sorbent assistance. The advantages
and limitations of different AWH strategies are respectively
discussed, as well as their water harvesting performance.
The various applications based on advanced AWH technologies
are also demonstrated. A prospective concept of
multifunctional water vapor harvesting panel based on
promising cooling material, inspired by silicon-based solar
energy panels, is finally proposed with a brief outlook of
its advantages and challenges.
REVERSIBLE ATMOSPHERIC WATER HARVESTING USING METAL-ORGANIC
FRAMEWORKS (8+ L/kg-MOF/day)
https://www.nature.com/articles/s41598-020-58405-9
ABSTRACT
The passive capture of clean water from humid air without
reliance on bulky equipment and high energy has been a
substantial challenge and has attracted significant interest
as a potential environmentally friendly alternative to
traditional water harvesting methods. Metal-organic
frameworks (MOFs) offer a high potential for this
application due to their structural versatility which
permits scalable, facile modulations of structural and
functional elements. Although MOFs are promising materials
for water harvesting, little research has been done to
address the microstructure-adsorbing characteristics
relationship with respect to the dynamic
adsorption-desorption process.
In this article, we present a parametric study of nine
hydrolytically stable MOFs with diverse structures for
unraveling fundamental material properties that govern the
kinetics of water sequestration in this class of materials
as well as investigating overall uptake capacity
gravimetrically. The effects of temperature, relative
humidity, and powder bed thickness on the
adsorption-desorption process are explored for achieving
optimal operational parameters. We found that Zr-MOF-808 can
produce up to 8.66 L/kg-MOF/day, an extraordinary finding
that outperforms any previously reported values for
MOF-based systems. The presented findings help to deepen our
understanding and guide the discovery of next-generation
water harvesting materials.
HARVESTING DRINKING WATER FROM HUMIDITY AROUND THE CLOCK (50 mL/m^2/hr)
https://www.science.org/doi/10.1126/sciadv.abf3978
ABSTRACT
Atmospheric water vapor is ubiquitous and represents a
promising alternative to address global clean water
scarcity. Sustainably harvesting this resource requires
energy neutrality, continuous production, and facility of
use. However, fully passive and uninterrupted 24-hour
atmospheric water harvesting remains a challenge. Here, we
demonstrate a rationally designed system that
synergistically combines radiative shielding and
cooling-dissipating the latent heat of condensation
radiatively to outer space-with a fully passive
superhydrophobic condensate harvester, working with a
coalescence-induced water removal mechanism. A rationally
designed shield, accounting for the atmospheric radiative
heat, facilitates daytime atmospheric water harvesting under
solar irradiation at realistic levels of relative humidity.
The remarkable cooling power enhancement enables dew mass
fluxes up to 50 mL/m^2/hr, close to the ultimate
capabilities of such systems. Our results demonstrate that
the yield of related technologies can be at least doubled,
while cooling and collection remain passive, thereby
substantially advancing the state of the art.
WARKA WATER TOWERS HARVEST DRINKABLE WATER FROM THE AIR (2+ min)
https://www.youtube.com/watch?v=THJVuinPbc0
The tower consists of a bamboo frame supporting a mesh
polyester material inside. Rain, fog and dew condenses
against the mesh and trickles down a funnel into a reservoir
at the base of the structure. A fabric canopy shades the
lower sections of the tower to prevent the collected water
from evaporating.
"Warka Water is currently represented by a tower that
reaches up to the sky to collect moisture from the air and
brings it down by gravity to the people," Vittori says.
The performance of the towers varies depending on the
weather, but Vittori's aim is to create a structure that
would enable the community to extract up to 100 litres of
water a day without the reservoir running dry.
CREATING WATER IN THE ATACAMA DESERT -
CREATING WATER FOUNDATION - DOCUMENTARY (9+ min)
https://www.youtube.com/watch?v=xsNNp9N2v9Y
Capturing water from the fog and producing food on the
driest place on earth, the Atacama Desert, Peru.
This water has two purposes: clean drinking water and to
grow food.
Water from the fog - Clean drinking water - organic
agriculture - Biochar - clean energy.
HYDROPHILIC NANOFIBERS IN FOG COLLECTORS FOR INCREASED WATER
HARVESTING EFFICIENCY (64 mL/cm^2/hr)
https://pubs.rsc.org/en/content/articlelanding/2020/ra/d0ra03939j#!
ABSTRACT
The water crisis is a big social problem and one of the
solutions are the Fog Water Collectors (FWCs) that are
placed in areas, where the use of conventional methods to
collect water is impossible or inadequate. The most common
fog collecting medium in FWC is Raschel mesh, which in our
study is modified with electrospun polyamide 6 (PA6)
nanofibers. The hydrophilic PA6 nanofibers were directly
deposited on Raschel meshes to create the hierarchical
structure that increases the effective surface area which
enhances the ability to catch water droplets from fog. The
meshes and the wetting behavior were investigated using a
scanning electron microscope (SEM) and environmental SEM
(ESEM). We performed the fog water collection experiments on
various configurations of Raschel meshes with hydrophilic
PA6 nanofibers. The addition of hydrophilic nanofibers
allowed us to obtain 3 times higher water collection rate of
collecting water from fog. Within this study, we show the
innovative and straightforward way to modify the existing
technology that improves water collection by changing the
mechanisms of droplet formation on the mesh.
SOLAR-POWERED SYSTEM EXTRACTS DRINKABLE WATER FROM "DRY" AIR
MIT ENGINEERS HAVE MADE THEIR INITIAL DESIGN MORE PRACTICAL,
EFFICIENT, AND SCALABLE. (~1 L/m^2/day)
https://news.mit.edu/2020/solar-extracts-drinkable-water-1014
https://www.youtube.com/watch?v=hoXj-j0VSTA&t=3s (1 min)
https://www.cell.com/joule/fulltext/S2542-4351(20)30444-X
Instead of the MOFs, the new design uses an adsorbent
material called a zeolite, which in this case is composed of
a microporous iron aluminophosphate. The material is widely
available, stable, and has the right adsorbent properties to
provide an efficient water production system based just on
typical day-night temperature fluctuations and heating with
sunlight.
The two-stage design developed by LaPotin makes clever use
of the heat that is generated whenever water changes phase.
The sun's heat is collected by a solar absorber plate at the
top of the box-like system and warms the zeolite, releasing
the moisture the material has captured overnight. That vapor
condenses on a collector plate - a process that releases
heat as well. The collector plate is a copper sheet directly
above and in contact with the second zeolite layer, where
the heat of condensation is used to release the vapor from
that subsequent layer. Droplets of water collected from each
of the two layers can be funneled together into a collecting
tank.
AN ACCIDENTALLY DISCOVERED CLASS OF NANOSTRUCTURED MATERIALS
CAN PASSIVELY HARVEST WATER FROM AIR
https://phys.org/news/2025-05-accidentally-class-nanostructured-materials-passively.html
https://www.science.org/doi/10.1126/sciadv.adu8349
OFF-GRID WATER WITH AIR AND SUNLIGHT (14+ min)
https://www.youtube.com/watch?v=KlUQ1pneow8
I make my own water using solar energy. This is my review of
SOURCE Hydropanels from Zero Mass Water. I spent my own
money on these. This is not a sponsored video nor do I get
any commission if you buy them. Let me know in the comments
if you want more content on these and thanks for watching!
How our drinking water could come from thin air
https://www.bbc.com/future/article/20240205-drinking-water-the-solar-panels-and-self-filling-coffee-machine-that-pull-moisture-out-of-the-air
https://www.science.org/doi/10.1126/sciadv.adu8349
sam.wormley@icloud.com