How does remote Joule heating of carbon nanotubes advance singularity timelines?

keefe

Carbon nanotubes: The weird world of 'remote Joule heating'

Minimizing Joule heating remains an important goal in the design of electronic devices^1, 2. The prevailing model of Joule heating relies on a simple semiclassical picture in which electrons collide with the atoms of a conductor, generating heat locally and only in regions of non-zero current density, and this model has been supported by most experiments. Recently, however, it has been predicted that electric currents in graphene and carbon nanotubes can couple to the vibrational modes of a neighbouring material^3, 4, heating it remotely⁵. Here, we use in situ electron thermal microscopy to detect the remote Joule heating of a silicon nitride substrate by a single multiwalled carbon nanotube. At least 84%of the electrical power supplied to the nanotube is dissipated directly into the substrate, rather than in the nanotube itself. Although it has different physical origins, this phenomenon is reminiscent of induction heating or microwave dielectric heating. Such an ability to dissipate waste energy remotely could lead to improved thermal management in electronic devices⁶."

These experiments seem extremely important in constructing AI singularity timelines, what does lesswrong think?

What is the impact on life extension research?

Carbon nanotubes in biology and medicine: In vitro and in vivo detection, imaging and drug delivery

Nanotechnology in Drug Delivery and Tissue Engineering: From Discovery to Applications

I don't see a line of inference free of holes, but one can imagine the sort of uses a scifi author would come up with.

Carbon nanotubes: The weird world of 'remote Joule heating'

Minimizing Joule heating remains an important goal in the design of electronic devices^1, 2. The prevailing model of Joule heating relies on a simple semiclassical picture in which electrons collide with the atoms of a conductor, generating heat locally and only in regions of non-zero current density, and this model has been supported by most experiments. Recently, however, it has been predicted that electric currents in graphene and carbon nanotubes can couple to the vibrational modes of a neighbouring material^3, 4, heating it remotely⁵. Here, we use in situ electron thermal microscopy to detect the remote Joule heating of a silicon nitride substrate by a single multiwalled carbon nanotube. At least 84%of the electrical power supplied to the nanotube is dissipated directly into the substrate, rather than in the nanotube itself. Although it has different physical origins, this phenomenon is reminiscent of induction heating or microwave dielectric heating. Such an ability to dissipate waste energy remotely could lead to improved thermal management in electronic devices⁶."

These experiments seem extremely important in constructing AI singularity timelines, what does lesswrong think?

What is the impact on life extension research?

Carbon nanotubes in biology and medicine: In vitro and in vivo detection, imaging and drug delivery

Nanotechnology in Drug Delivery and Tissue Engineering: From Discovery to Applications

I don't see a line of inference free of holes, but one can imagine the sort of uses a scifi author would come up with.

What kind of explanation are you looking for? Are you a physicist? Have you taken physics?

Assuming you know some things but aren't a condensed-matter physicist: 1) single-layered graphene's intrinsic scattering rate is extremely low, so nearly anything else that causes scattering is going to dominate. 2) it is an exceptionally poor screener of electric fields, due to the low density of states. 3) it is entirely surface, so there is no interior region to be unaffected by boundary effects (though graphene is usually in poor mechanical contact with the substrate, this loose coupling is not weak enough to strongly suppress surface phonon scattering). Note that 'the top side, away from the substrate' is not distinct - the relevant carrier electron states straddle the center plane.

So, what happens? You've got an electron in the electrical field, accelerating. It eventually scatters. What does it scatter off of? The substrate, mainly, by one mechanism or another. Whichever it is, some energy is dissipated directly into the substrate (that's what it bounced off of), and the electron bounces off in some other direction. This electron bounce is not heat - the electrical field just goes back to pushing it forward again, and it goes - very orderly except for the isolated scattering instances.

The main ways the graphene itself gets warmer are by a) a carrier electron does manage to scatter off of a graphene lattice phonon (this is a really weak process, but it happens, and when you get rid of the substrate it dominates) ; and b) phonons from the substrate are transmitted into the graphene lattice (this is also weak because graphene binds poorly to the substrates mechanically speaking, but it's not extremely weak).

That's the summary of what's going on. It applies equally to single-walled carbon nanotubes, and to a lesser extent, multi-layered graphene and multi-walled carbon nanotubes.

Thank you or the well considered response, actually helpful. You have my background about right, I published in a physicists in medicine conference and have the normal background in comparch and whatever classes I took for my math double. Definitely not a condensed matter physicist, will have to read more on phonons.

The idea that this is a hollow tube and so there is no interior region to be effected does seem intuitive. The thing that jumped out at me is that the tube itself remained cool.

I don't have a good understanding of quantum electrodynamics or... (read more)

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How does remote Joule heating of carbon nanotubes advance singularity timelines?

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How does remote Joule heating of carbon nanotubes advance singularity timelines?

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