Posted on 08/17/2019 7:12:52 AM PDT by BenLurkin
Stanford researchers have shown that a few layers of atomically thin materials, stacked like sheets of paper atop hot spots, can provide the same insulation as a sheet of glass 100 times thicker. In the near term, thinner heat shields will enable engineers to make electronic devices even more compact than those we have today...
The heat we feel from smartphones or laptops is actually an inaudible form of high-frequency sound. If that seems crazy, consider the underlying physics. Electricity flows through wires as a stream of electrons. As these electrons move, they collide with the atoms of the materials through which they pass. With each such collision an electron causes an atom to vibrate, and the more current flows, the more collisions occur, until electrons are beating on atoms like so many hammers on so many bells—except that this cacophony of vibrations moves through the solid material at frequencies far above the threshold of hearing, generating energy that we feel as heat.
Thinking about heat as a form of sound inspired the Stanford researchers to borrow some principles from the physical world. From his days as a radio DJ at Stanford's KZSU 90.1 FM, Pop knew that music recording studios are quiet thanks to thick glass windows that block the exterior sound. A similar principle applies to the heat shields in today's electronics. If better insulation were their only concern, the researchers could simply borrow the music studio principle and thicken their heat barriers. But that would frustrate efforts to make electronics thinner. Their solution was to borrow a trick from homeowners, who install multi-paned windows—usually, layers of air between sheets of glass with varying thickness—to make interiors warmer and quieter.
(Excerpt) Read more at phys.org ...
Hmmm. I need to re-study conduction bands in metals. But at first blush this seems to me to violate the Born-Oppenheimer approximation. How many electrons are we talking about?
Very cool.
Nothing new, they figured this out building the LEM.
This must be the new science they're teaching to go along with the new math.
That ten atom thick layer is EM shielding, not “sound” dampening.
The Born-Oppenheimer approximation merely assumes that because ion motion due to vibrations is slow compared to electron orbit frequencies that the electron orbits in a molecule can be computed assuming the ion positions are static. That approximation is independent of this model, that conducting electrons collide with and scatter off of ions setting the lattice vibrating (which are called acoustic waves). In the solid state at ordinary temperatures acoustic vibrations are the dominant carrier of thermal energy (compared to electron thermal conduction)
Thermal waves in solid materials are just a random jumble of small amplitude incoherent sound waves in the material
Interesting.
I like your description much better.
On the atomic level, as the electrons move through the orbitals, is the energy infrared or friction or both?
I would think if they don’t provide heat dissipation things will get hotter inside and overheat the particular component.
The energy levels of an electron in a semi conductor can range from the optical equivalent of infrared up to the near ultraviolet (this e.g. blue LEDs).
Rutherford wept.
Thats what happens when you don’t do the final review/edit what your PR department puts out!
You can hear it on all high tension supply lines. And the Native Americans called the telegraph lines the “singing wires”. These are those vibrations.
A nostalgia physics thread!
It’s so comforting thinking in terms of classical physics. Quantum theory took all the fun away.
No pun intended good one.
That’s my reaction, too - I thought the whole game was dissipating the heat from transistors, not retaining it.
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