Real-time CO2 monitoring without batteries or external power
(news.kaist.ac.kr)70 points by gnabgib 16 hours ago
70 points by gnabgib 16 hours ago
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.
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?
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.
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.
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.
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?
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?"
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.
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.
Please don't waste your time on this. CO2 has very minimal, negligible lighthouse effect. It is water that has this ability the most (and therefore clouds). It can keep the weather colder during daytime and hotter during night time. Please educate yourself. Plants need CO2, and in return, they provide us O2. Without CO2, you break this cycle, and there will be no life on Earth at all.
The reason we have climate change is because Earth's orbit changes periodically due to Milankovitch cycles. This can be seen throughout the history. We are just moving out of a mini ice age.
https://www.space.com/milankovitch-cycles#section-do-milanko...
From the article:
Climate change deniers like to argue that our planet would warm up no matter what, even without the greenhouse gas emissions that humankind is releasing into Earth's atmosphere.
Maliverno, however, says that the geological record doesn't suggest that this would be the case.
"There have been several campaigns in the past when researchers drilled into the Antarctic ice sheets and took samples from deep below the surface, reaching layers that are up to 800,000 years old," Maliverno said. "They analyzed the concentrations of carbon dioxide trapped in those layers. There are tiny air bubbles in the ice, essentially samples of the atmosphere as it was back then, and they found that even during the interglacials, the maximum amount of carbon dioxide was nowhere near the amount that we see today."
Moreover, Maliverno added, computer modeling studies that tried to reproduce the current climate change using only natural variables, such as the Milankovitch cycles, couldn't match the rate of warming we see today.
Anyone can put up an article on the net and claim they are right. I think what we need is bringing back the forests.
I didn't reply with that information for your benefit. I replied to add context for other readers.
Either you have a specific claim against this publisher, article, or point or you don't. This is a respected science oriented publisher with interviews of scientists talking about their research in their own field.
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