November 2, 2025 • 10 mins
Researchers in Japan have created a paper-thin metal-organic framework (MOF) film that changes color in response to alcohol vapors, allowing for simple alcohol measurement using a smartphone camera. This innovative technology offers a portable, cost-effective alternative to traditional alcohol sensing methods, with potential applications in food and beverage, environmental monitoring, and healthcare.
Read the full article at https://www.paperleap.com/blog/articles/a-film-that-can-sense-alcohol-with-your-smartphone-0cccuo
Read the full article at https://www.paperleap.com/blog/articles/a-film-that-can-sense-alcohol-with-your-smartphone-0cccuo
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Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:00):
Welcome to the paper Leap podcast, where a science takes
the mic. Each episode, we discuss cutting edge research, groundbreaking discoveries,
and the incredible people behind them, across disciplines and across
the world. Whether you're a curious mind, a researcher, or
just love learning, you're in the right place before we start.
Speaker 2 (00:21):
Don't forget to.
Speaker 1 (00:22):
Subscribe so you never miss an insight. All the content
is also available on paperleap dot com. Okay, ready, let's start.
Checking The alcohol content of wine, sake, or even your
breath could soon be as simple as looking at the
color of a thin film through your phone's camera. A
(00:43):
research team in Japan has developed a new kind of
alcohol sensor that changes color when it detects ethanol, turning
a futuristic concept into a working reality. This innovation goes
far beyond convenience. Alcohol or ethanol. Eth is one of
the world's most widely used chemicals. It appears in fuels, disinfectants, medicines,
(01:06):
and of course, beverages. Being able to measure alcohol concentration
quickly and accurately is vital for industries from food and
drink production to environmental monitoring and healthcare. Traditionally, detecting alcohol
requires either specialized laboratory equipment or electronic gas sensors that
need external power. But the researchers behind a study published
(01:29):
in Small Science, a journal from Wilie, have developed a
clever alternative, a paper thin film made from a copper
based metal organic framework MOF that visibly changes color in
response to alcohol vapors. Even better, the color change can
be analyzed with nothing more than a smartphone camera. The
(01:50):
work was realized by Utotachi, Kenji Okada, Arisa Fukatsu, and
Masahide Takahashi from Osaka Metropolitan University in collaboration with ut
Suji at Kyushu University. Together, they've opened up an entirely
new way to think about chemical sensing. Why alcohol detection.
Speaker 2 (02:12):
If you've ever brewed beer or fermented kombucha, you know
how important it is to control alcohol content. Too little
and the product won't taste righte Too much and it
can be unsafe or spoil regulatory limits. On an industrial scale,
precision is even more crucial. Outside of food, alcohol detection
has other important roles. Doctors may need to measure blood
(02:35):
alcohol levels and patients factories must keep track of ethanol
emissions for safety and environmental compliance, breathalyzers are used to
check whether drivers are intoxicated. In short, there are countless
moments when knowing the exact ethanol concentration quickly and reliably
can make a big difference. Yet current sensing technologies have drawbacks.
(02:59):
Metal oxide gas sensors are compact and cheap, but they
need electricity and aren't always precise across wide ranges of concentrations.
High end lab instruments like spectrometers give vaccurate readings, but
are expensive and not portable. This is where color comes in.
A simple color change is one of the most intuitive
(03:19):
signals humans can interpret. Think of litmus paper turning red
or blue to indicate acidity. A similar idea called chromicism
has been explored for alcohol sensing, but until now no
material offered both sensitivity and reversibility across the full range
of ethanol concentrations. At the heart of this breakthrough is
(03:42):
a material known as a metal organic framework. MOFs are
crystalline structures made by linking metal ions with organic molecules.
You can picture them as scaffolds with nanoscale pores like
molecular sponges that can silk up specific gases or liquids.
What makes MOFs fascinating is their tuneability. By swapping out
(04:04):
different metals or organic linkers, scientists can create frameworks with
custom pore sizes and chemical properties. Some MOFs can store
gases like hydrogen, others can catalyze reactions, and as shown here,
some can change color when molecules slip inside their pores.
Vosaka Kyushu team focused on a specific mof called SeeU
(04:27):
MOUF seventy four, built around copper ions. This framework features
open metal sites that readily interact with guest molecules such
as water or ethanol. When ethanol enters, the structure's electronic
properties shift, leading to a visible color change. The concept
sounds straightforward, but there was a big hurdle. In powdered form.
(04:48):
See U MOF seventy four scatters too much light, making
the color change hard to see. The researchers solved this
by creating ultra thin, transparent films of the material, which
allowed clean, easily visible shifts in color. So how does
this film actually work? When exposed to ethanol vapor or
liquid mixtures of ethanol and water, the film changes its
(05:11):
hue at lower ethanol concentrations, it looks more orange. As
the concentration rises, it shifts toward brown. These changes are
not just subtle laboratory effects. They're dramatic enough to be
detected by an ordinary smartphone camera. Here's where the team
had a brilliant idea. The researchers developed a smartphone app
(05:31):
that reads the RGB color values from a photo of
the film and translates them into alcohol concentrations. The app
could successfully measure the alcohol content of commercial beverages like sake, whiskey,
and rum, and the results matched the labeled percentages. That
means you could, in principle, check whether your bottle of
wine really contains thirteen point five percent alcohol or whether
(05:54):
your sake matches its listed strength, all with a simple,
portable test. Even more impressively, color changes in the film
are reversible and repeatable. The mouth can absorb and release
ethanol molecules over and over again without degrading. In tests,
the films retained their performance after at least fifty cycles
(06:15):
of alcohol exposure. If you dig deeper into the physics,
the color change comes from tiny shifts in the electronic
structure of the mouth when ethanol molecules enter the copper framework,
they interact with specific bonds inside the structure, slightly altering
their links. These changes, in turn modify the material's band gap,
(06:35):
the energy difference that determines how it absorbs light. In
simpler terms, the mouth acts like a mood ring for molecules.
Different guess molecules tweak its internal structure in different ways,
and those tweaks translate into visible colors. The team's experiments,
supported by advanced computer simulations, showed that water, ethanol, and
(06:57):
other alcohols like to propenol, all affect did the cu
MO seventy four framework differently, Ethanol crucially produce distinct and
measurable color shifts across the entire concentration spectrum. The potential
applications are wide ranging. For instance, in the food and
beverage industry, quality control during brewing, wine making, or distilling
(07:19):
could become faster and easier. It also has potential applications
in environmental monitoring, where factories could track ethanol emissions without
needing complex equipment. In healthcare, breath alcohol tests could be simplified,
making portable and expensive alternatives to current breathalyzers possible. And finally,
with just a film and a smartphone, students or hobbyists
(07:42):
could explore chemistry and action, with significant implications for education
and citizen science. What makes this work stand out is
its combination of simplicity, portability, and full range sensitivity. It
doesn't require power hungry electronics, expensive space traumeters, or specialized training.
The film is small and cheap to produce, and smartphones
(08:05):
are already everywhere. This is because the approach overcomes the
limitations of older chromicism based sensors, which often suffered from
low sensitivity, irreversibility, or only worked at certain concentration ranges.
By harnessing the unique properties of cu MO seventy four,
the team has created a truly versatile solution. What's next.
(08:28):
While this study represents a proof of concept, there is
plenty of room for future development. The films could be
integrated into compact sensor devices or combined with custom apps
for specific industries. Researchers could also explore tailoring other MOFs
to detect different gases or liquids. Imagine a family of
color changing films for everything from carbon dioxide to hazardous pollutants.
(08:53):
There's also potential in consumer applications. A thin sticker on
a bottle cap that changes color with alcohol strength, a
portable breath test you can use privately before driving. The
possibilities are tantalizing. Chemistry doesn't always have to be hidden
in laboratories and complicated instruments. Sometimes molecules announce their presence
(09:15):
with something as simple and human as a shift in color.
The research team behind the study has shown that by
harnessing the power of MOFs, we can literally watch chemistry happen, and,
with the help of our smartphones, turn those colors into
meaningful measurements, until we will be able to raise a
glass and answer the question how strong is this drink
(09:37):
by snapping a photo. That's it for this episode of
the paper Leap podcast. If you found it thought provoking, fascinating,
or just informative, share it with the fellow science nerd.
For more research highlights and full articles, visit paperleaf dot com.
Also make sure to subscribe to the podcast. We've got
(09:58):
plenty more discoveries to it. Until next time, Keep questioning,
keep learning,
Welcome to the paper Leap podcast, where a science takes
the mic. Each episode, we discuss cutting edge research, groundbreaking discoveries,
and the incredible people behind them, across disciplines and across
the world. Whether you're a curious mind, a researcher, or
just love learning, you're in the right place before we start.
Speaker 2 (00:21):
Don't forget to.
Speaker 1 (00:22):
Subscribe so you never miss an insight. All the content
is also available on paperleap dot com. Okay, ready, let's start.
Checking The alcohol content of wine, sake, or even your
breath could soon be as simple as looking at the
color of a thin film through your phone's camera. A
(00:43):
research team in Japan has developed a new kind of
alcohol sensor that changes color when it detects ethanol, turning
a futuristic concept into a working reality. This innovation goes
far beyond convenience. Alcohol or ethanol. Eth is one of
the world's most widely used chemicals. It appears in fuels, disinfectants, medicines,
(01:06):
and of course, beverages. Being able to measure alcohol concentration
quickly and accurately is vital for industries from food and
drink production to environmental monitoring and healthcare. Traditionally, detecting alcohol
requires either specialized laboratory equipment or electronic gas sensors that
need external power. But the researchers behind a study published
(01:29):
in Small Science, a journal from Wilie, have developed a
clever alternative, a paper thin film made from a copper
based metal organic framework MOF that visibly changes color in
response to alcohol vapors. Even better, the color change can
be analyzed with nothing more than a smartphone camera. The
(01:50):
work was realized by Utotachi, Kenji Okada, Arisa Fukatsu, and
Masahide Takahashi from Osaka Metropolitan University in collaboration with ut
Suji at Kyushu University. Together, they've opened up an entirely
new way to think about chemical sensing. Why alcohol detection.
Speaker 2 (02:12):
If you've ever brewed beer or fermented kombucha, you know
how important it is to control alcohol content. Too little
and the product won't taste righte Too much and it
can be unsafe or spoil regulatory limits. On an industrial scale,
precision is even more crucial. Outside of food, alcohol detection
has other important roles. Doctors may need to measure blood
(02:35):
alcohol levels and patients factories must keep track of ethanol
emissions for safety and environmental compliance, breathalyzers are used to
check whether drivers are intoxicated. In short, there are countless
moments when knowing the exact ethanol concentration quickly and reliably
can make a big difference. Yet current sensing technologies have drawbacks.
(02:59):
Metal oxide gas sensors are compact and cheap, but they
need electricity and aren't always precise across wide ranges of concentrations.
High end lab instruments like spectrometers give vaccurate readings, but
are expensive and not portable. This is where color comes in.
A simple color change is one of the most intuitive
(03:19):
signals humans can interpret. Think of litmus paper turning red
or blue to indicate acidity. A similar idea called chromicism
has been explored for alcohol sensing, but until now no
material offered both sensitivity and reversibility across the full range
of ethanol concentrations. At the heart of this breakthrough is
(03:42):
a material known as a metal organic framework. MOFs are
crystalline structures made by linking metal ions with organic molecules.
You can picture them as scaffolds with nanoscale pores like
molecular sponges that can silk up specific gases or liquids.
What makes MOFs fascinating is their tuneability. By swapping out
(04:04):
different metals or organic linkers, scientists can create frameworks with
custom pore sizes and chemical properties. Some MOFs can store
gases like hydrogen, others can catalyze reactions, and as shown here,
some can change color when molecules slip inside their pores.
Vosaka Kyushu team focused on a specific mof called SeeU
(04:27):
MOUF seventy four, built around copper ions. This framework features
open metal sites that readily interact with guest molecules such
as water or ethanol. When ethanol enters, the structure's electronic
properties shift, leading to a visible color change. The concept
sounds straightforward, but there was a big hurdle. In powdered form.
(04:48):
See U MOF seventy four scatters too much light, making
the color change hard to see. The researchers solved this
by creating ultra thin, transparent films of the material, which
allowed clean, easily visible shifts in color. So how does
this film actually work? When exposed to ethanol vapor or
liquid mixtures of ethanol and water, the film changes its
(05:11):
hue at lower ethanol concentrations, it looks more orange. As
the concentration rises, it shifts toward brown. These changes are
not just subtle laboratory effects. They're dramatic enough to be
detected by an ordinary smartphone camera. Here's where the team
had a brilliant idea. The researchers developed a smartphone app
(05:31):
that reads the RGB color values from a photo of
the film and translates them into alcohol concentrations. The app
could successfully measure the alcohol content of commercial beverages like sake, whiskey,
and rum, and the results matched the labeled percentages. That
means you could, in principle, check whether your bottle of
wine really contains thirteen point five percent alcohol or whether
(05:54):
your sake matches its listed strength, all with a simple,
portable test. Even more impressively, color changes in the film
are reversible and repeatable. The mouth can absorb and release
ethanol molecules over and over again without degrading. In tests,
the films retained their performance after at least fifty cycles
(06:15):
of alcohol exposure. If you dig deeper into the physics,
the color change comes from tiny shifts in the electronic
structure of the mouth when ethanol molecules enter the copper framework,
they interact with specific bonds inside the structure, slightly altering
their links. These changes, in turn modify the material's band gap,
(06:35):
the energy difference that determines how it absorbs light. In
simpler terms, the mouth acts like a mood ring for molecules.
Different guess molecules tweak its internal structure in different ways,
and those tweaks translate into visible colors. The team's experiments,
supported by advanced computer simulations, showed that water, ethanol, and
(06:57):
other alcohols like to propenol, all affect did the cu
MO seventy four framework differently, Ethanol crucially produce distinct and
measurable color shifts across the entire concentration spectrum. The potential
applications are wide ranging. For instance, in the food and
beverage industry, quality control during brewing, wine making, or distilling
(07:19):
could become faster and easier. It also has potential applications
in environmental monitoring, where factories could track ethanol emissions without
needing complex equipment. In healthcare, breath alcohol tests could be simplified,
making portable and expensive alternatives to current breathalyzers possible. And finally,
with just a film and a smartphone, students or hobbyists
(07:42):
could explore chemistry and action, with significant implications for education
and citizen science. What makes this work stand out is
its combination of simplicity, portability, and full range sensitivity. It
doesn't require power hungry electronics, expensive space traumeters, or specialized training.
The film is small and cheap to produce, and smartphones
(08:05):
are already everywhere. This is because the approach overcomes the
limitations of older chromicism based sensors, which often suffered from
low sensitivity, irreversibility, or only worked at certain concentration ranges.
By harnessing the unique properties of cu MO seventy four,
the team has created a truly versatile solution. What's next.
(08:28):
While this study represents a proof of concept, there is
plenty of room for future development. The films could be
integrated into compact sensor devices or combined with custom apps
for specific industries. Researchers could also explore tailoring other MOFs
to detect different gases or liquids. Imagine a family of
color changing films for everything from carbon dioxide to hazardous pollutants.
(08:53):
There's also potential in consumer applications. A thin sticker on
a bottle cap that changes color with alcohol strength, a
portable breath test you can use privately before driving. The
possibilities are tantalizing. Chemistry doesn't always have to be hidden
in laboratories and complicated instruments. Sometimes molecules announce their presence
(09:15):
with something as simple and human as a shift in color.
The research team behind the study has shown that by
harnessing the power of MOFs, we can literally watch chemistry happen, and,
with the help of our smartphones, turn those colors into
meaningful measurements, until we will be able to raise a
glass and answer the question how strong is this drink
(09:37):
by snapping a photo. That's it for this episode of
the paper Leap podcast. If you found it thought provoking, fascinating,
or just informative, share it with the fellow science nerd.
For more research highlights and full articles, visit paperleaf dot com.
Also make sure to subscribe to the podcast. We've got
(09:58):
plenty more discoveries to it. Until next time, Keep questioning,
keep learning,
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