3 ms·

Hi! OROS Apparel team here :) The aerogel in the gloves is coated on one side with pure graphene. Graphene is the exact opposite of aerogel. While aerogel has

Hi! OROS Apparel team here :) The aerogel in the gloves is coated on one side with pure graphene. Graphene is the exact opposite of aerogel. While aerogel has an incredibly low thermal conductivity (making it an awesome insulator), pure graphene has an incredibly high thermal conductivity (making it a great conductor). Most metals act the same way as graphene (they have high thermal conductivities)-- think about the last time you got in your car on a hot summer day and went to put your seatbelt on. You accidentally touched the metal part of the seatbelt and immediately regretted your decision. It was hot. Metals, like graphene, pick up heat in the presence of heat (hence high thermal conductivity). So, imagine the graphene coated side of the aerogel is facing your hand. Your hand releases heat. The heat gets picked up by the graphene. The graphene heats up. The heat does not easily escape, because on the other side of the graphene is aerogel (an insulator). You now have, essentially, a self heating glove without a battery.

xutopia 11y ago
The claim of being blasted with liquid nitrogen is kind of silly. I put my hand in liquid nitrogen for 10 seconds before getting scared and my hand didn't get much colder than if I had put it in water.
- slavik81 11y ago
  Ten seconds seems like quite a long time to submerge your hand in liquid nitrogen without ending up with serious burns. I'm not sure I believe that. Perhaps it was shorter and you were briefly protected by this: > Dr Alex Valavanis [notes that] liquid nitrogen "does not immediately feel cold". He says the delay in feeling the cold is down to the "Leidenfrost effect" - which happens when a liquid, in near contact with a mass significantly hotter than the liquid's boiling point, produces an insulating vapour layer. http://www.bbc.com/news/magazine-19870668 http://www.bbc.com/news/magazine-19870668
  - fluxquanta 11y ago
    I had a physics professor who, on a couple occasions, would gargle a small amount of liquid nitrogen. Between the constant motion of the liquid and the Leidenfrost effect, he was fine. Still wouldn't try it myself.
cmdrfred 11y ago
> a self heating glove without a battery. So if I were to say leave this glove on my countertop, it would be warmer than room temperature inside?
erroneousfunk 11y ago
I'm still a little confused about how something with a high thermal conductivity improves things. If your glove is at room temperature and you stick your hand in, it will initially feel colder, because of the high thermal conductivity of the graphene, correct? The side of the aerogel inside the glove will also warm more rapidly than if the graphene wasn't there. When the graphene reaches equilibrium with your warm hand on one side and the cooler aerogel on the other side, it will rapidly balance any changes in equilibrium on either side, and actually make your hand feel cooler faster, if there's a sudden drop in temperature. So, are you getting thermal conductivity confused with specific heat?
- Terr_ 11y ago
  I suppose that a thermally-conductive inner layer might help in terms of perceived warmth, if it reduces localized "cold spots" that might be more-noticeable. For example, warming the sensitive tips of your fingers with heat carried from your palm, etc.
Terr_ 11y ago
> Your hand releases heat. True, but I already own a "self-heating hand". If someone is selling a "self-heating glove" I expect it brings its own heat to the party.
snowwrestler 11y ago
The graphene layer harms the warmth of the glove by transporting heat from the hand, where it is needed, to the insulation, where it is not needed. A perfectly insulating glove would not conduct heat at all, in any way. Actually this would be bad, because the hand would overheat. Welcome to Hacker News! We understand physics here.
- msandford 11y ago
  > Welcome to Hacker News! We understand physics here. I know you're not really supposed to make "ha ha me too!" reddit-esque comments here, but I waited until things had died down! And that gave me a hearty chuckle.

xutopia 11y ago

The claim of being blasted with liquid nitrogen is kind of silly. I put my hand in liquid nitrogen for 10 seconds before getting scared and my hand didn't get much colder than if I had put it in water.

slavik81 11y ago
Ten seconds seems like quite a long time to submerge your hand in liquid nitrogen without ending up with serious burns. I'm not sure I believe that. Perhaps it was shorter and you were briefly protected by this: > Dr Alex Valavanis [notes that] liquid nitrogen "does not immediately feel cold". He says the delay in feeling the cold is down to the "Leidenfrost effect" - which happens when a liquid, in near contact with a mass significantly hotter than the liquid's boiling point, produces an insulating vapour layer. http://www.bbc.com/news/magazine-19870668 http://www.bbc.com/news/magazine-19870668
- fluxquanta 11y ago
  I had a physics professor who, on a couple occasions, would gargle a small amount of liquid nitrogen. Between the constant motion of the liquid and the Leidenfrost effect, he was fine. Still wouldn't try it myself.

cmdrfred 11y ago

> a self heating glove without a battery. So if I were to say leave this glove on my countertop, it would be warmer than room temperature inside?

erroneousfunk 11y ago

I'm still a little confused about how something with a high thermal conductivity improves things. If your glove is at room temperature and you stick your hand in, it will initially feel colder, because of the high thermal conductivity of the graphene, correct? The side of the aerogel inside the glove will also warm more rapidly than if the graphene wasn't there. When the graphene reaches equilibrium with your warm hand on one side and the cooler aerogel on the other side, it will rapidly balance any changes in equilibrium on either side, and actually make your hand feel cooler faster, if there's a sudden drop in temperature. So, are you getting thermal conductivity confused with specific heat?

Terr_ 11y ago
I suppose that a thermally-conductive inner layer might help in terms of perceived warmth, if it reduces localized "cold spots" that might be more-noticeable. For example, warming the sensitive tips of your fingers with heat carried from your palm, etc.

Terr_ 11y ago

> Your hand releases heat. True, but I already own a "self-heating hand". If someone is selling a "self-heating glove" I expect it brings its own heat to the party.

snowwrestler 11y ago

The graphene layer harms the warmth of the glove by transporting heat from the hand, where it is needed, to the insulation, where it is not needed. A perfectly insulating glove would not conduct heat at all, in any way. Actually this would be bad, because the hand would overheat. Welcome to Hacker News! We understand physics here.

msandford 11y ago
> Welcome to Hacker News! We understand physics here. I know you're not really supposed to make "ha ha me too!" reddit-esque comments here, but I waited until things had died down! And that gave me a hearty chuckle.