[HN Gopher] Real-time CO2 monitoring without batteries or extern...
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Real-time CO2 monitoring without batteries or external power
Author : gnabgib
Score : 120 points
Date : 2025-06-15 22:29 UTC (1 days ago)
(HTM) web link (news.kaist.ac.kr)
(TXT) w3m dump (news.kaist.ac.kr)
| noisy_boy wrote:
| Tangential/Spoiler: I came to know about Kaist (Korea Advanced
| Institute of Science & Technology) in the Netflix series Devil's
| Plan (season 2) which had two of its students as the top three
| contestants.
| nikolayasdf123 wrote:
| anyone can explain why this is such a big breakthrough?
|
| vibration powered electricity generator is not new, neither is
| CO2 monitoring. so what's the big deal?
| dfex wrote:
| More concerning - can anyone explain why there is such a
| variation in the results from the DC powered unit vs. the TENG-
| powered one? The graph at the bottom of the report shows a
| difference of 30-50ppm between both units when they are sitting
| side by side on the bench.
| zipping1549 wrote:
| I skimmed the original article and it only mentions the graph
| and says that it's "comparable to DC powered unit". I'm
| guessing < 100ppm difference is somewhat acceptable?
| dfex wrote:
| You might be right - it's just odd that it's always showing
| "more" rather than similar amounts.
|
| Also, according to Claude[1] a 50ppm difference is
| equivalent to around 25 years current atmospheric carbon
| increase.
|
| * Pre-industrial (1700s): ~280 ppm
|
| * 1958 (when systematic measurements began): ~315 ppm
|
| * 2000: ~370 ppm
|
| * 2015: ~400 ppm (milestone crossed)
|
| * Current: ~420-425 ppm
|
| [1] "What is the normal range for background CO2
| concentrations in the air?"
| strogonoff wrote:
| It's crazy to think that many people alive today
| experienced a 30% increase in ambient atmospheric carbon
| dioxide concentration within their lifetimes.
| devmor wrote:
| You're missing some deeply important context there, which
| is that those measurements are for outdoor atmospheric
| CO2 only.
|
| Average indoor air quality ranges from 400-1000 ppm CO2,
| with adverse mental effects starting to appear close to
| 2000 ppm.
|
| In that context, you can see why a 50 ppm difference is
| marginal. This is why asking an LLM is not generally a
| great idea for understanding something - you need to
| follow it up with more research.
| jobs_throwaway wrote:
| > adverse mental effects starting to appear close to 2000
| ppm.
|
| cognition is harmed starting at 1000ppm
| (https://pmc.ncbi.nlm.nih.gov/articles/PMC3548274/)
| freeone3000 wrote:
| Not odd at all that it's always showing more -- sensor
| error is often biased. This is within the listed range
| though.
| officeplant wrote:
| I have to know, what's the the rise of people like you
| chiming in with AI sourced tidbits? It's like the people
| with no knowledge on a subject that use google as a quick
| catch up tool so they can participate in a conversation,
| but somehow even worse. Are they the same people, but now
| lazier or just true believers in the non-sense engines?
| callmemclovin wrote:
| That's in the normal range of accuracy of modern CO2 sensors,
| for example SCD40 from Sensirion is described with an
| accuracy of +-50.0 ppm +-5.0 %m.v.
| jtrueb wrote:
| That's if the voltage supply was stable and within
| electrical specs for a sufficient period of time. We can
| see this is a snippet 2 hours into the discontinous
| collection.
|
| 3.6V is the maximum value that the nrf52832 SoC can handle.
| I would suspect the VDD is variable.
| ahaucnx wrote:
| Actually the real accuracy is much better, especially with
| optical NDIR sensors.
|
| We do a lot of testing against reference grade sensors and
| typically see very good performance and reproducibility
| [1].
|
| [1] https://www.airgradient.com/blog/performance-of-low-
| cost-co2...
| nashashmi wrote:
| A low powered co2 monitor is likely a big deal. And one that
| fits to specific power generation systems is even a bigger
| deal.
| ChemSpider wrote:
| The challenge with CO2 monitoring is the sensor, not the
| electronics. Sensor accurracy and service life are key
| information.
|
| It is easy to create a low power chemical CO2 sensors with a
| service life of a few weeks/months. Obviously not pratical
| for real world applications. So critical data is missing in
| this press release.
| nradov wrote:
| Replacing sensors every few weeks is totally practical for
| some real-world applications such as life support systems.
| mschuster91 wrote:
| The power consumption is the thing, these sensors usually run
| in the low-digit milliwatt range... and they managed to get it
| to run on a power generation of 0.5 mW, making the combination
| of both possible at all.
| Gravityloss wrote:
| I was thinking would there be a passive chemical alternative,
| something that changed color according to CO2 level. Kind of:
| https://en.wikipedia.org/wiki/Bicarbonate_indicator
| mschuster91 wrote:
| These generally - as the article indicates - have the issue
| that they aren't just sensitive to CO2 but virtually anything
| else.
|
| You could maybe get by with some sort of antibody coagulation
| stuff like in many rapid test strips, but these are to my
| knowledge not reversible.
| supportengineer wrote:
| I was hoping it would be a mechanical system that uses no
| electricity at all
| tempodox wrote:
| > The core of this new system is an "Inertia-driven Triboelectric
| Nanogenerator (TENG)" that converts vibrations (with amplitudes
| ranging from 20-4000 micrometer and frequencies from 0-300 Hz)
| generated by industrial equipment or pipelines into electricity.
| This enables periodic CO2 concentration measurements and wireless
| transmission without the need for batteries.
|
| Ingenious, I love it.
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