Tours Through Physics: Nanoplasmonics, Tiny Spheres with BIG Potential

[@nickhoffmann10]

You're definitely a new rising star in science communication

[@igd2108]

Great stuff! I'm actually doing my undergraduate thesis around the potential use of hollow gold nanoparticles to enhance radiotherapy so it's a great coincidence I've found this channel. Keep em coming!

[@jeanmahe8657]

What a great channel... i wish you the best

[@zikermu]

Thank you very much for this very educational explanation.

[@ItsTheSebbe]

Loving the videos! Keep them up!

[@ZeRandomZ]

Fantastic Video

[@stillpointx2623]

Anyone know where to find any lectures dealing with nanobubbles with electrostatics? The paper is called Massive generation of metastable bulk nanobubbles in water by external electric fields. I haven't been able to find a video showing how to make these.

[@abgarc1931]

Do you have specific bibliography that you recommend for this subjects? Thanks.

[@atomsandsporks6760]

Apologies for the extreme delay in responding :S. A great place to start, if you have access, is always Physics Today. Specifically this 2011 article by Mark Stockman: physicstoday.scitation.org/doi/full/10.1063/1.3554315 Physics Today is always great for checking out a new area in physics.

[@dalarev9858]

Super well done. Thanks for the content!

[@atomsandsporks6760]

Thanks!

[@marshell13]

Definitely glad I discovered your channel. You really know how to explain stuff.

[@swapnilchitriv3196]

Thanks for this video

[@ruchisingh2177]

Amazing

[@ravishanker8539]

Brilliant!

[@yasar_102]

This really helped. Thanks

[@sohamshirodkar9463]

Very interesting !

[@FaruqAtilola]

The crash course vibe 😄😄

[@aladonai]

First of all, awesome channel man! I've a question I don't know if I understood the concept very well but here we go ... the incidence of light generates a movement of the electromagnetic field of the nanoparticles right? If I submitted a patient to a CT (computed tomography) scan or an MRI scan (magnetic resonance) , could the magnetic field of these devices trigger the same behavior as the laser in the nanoparticles, or do they depend exclusively on the light of a laser? did I travel a lot on that question?

[@aladonai]

The idea is to get the "tumor" region bright in an exam (instead of 'kill" them") only to identification purposes ...

[@atomsandsporks6760]

Neither CT nor MRI would have the intended effect. CT is X-rays which, I supposed if anything, would just charge the spheres by stripping away electrons, and MRI would do nasty things as the magnetic fields in MRIs are outrageously high and they are spheres made of metal. I'm working on the third video now about the physical origin of the effect, but the key ingredient is that an electromagnetic wave has an electric field that oscillates in direction (i.e. its direction flips up, down, up, down, etc). And in a metal you have "mobile" negative charges that can move separately from the positive charge (i.e. electrons are delocalized and not bound to any one atom, like they are in an insulator). Because of this when you apply an electric field you separate the two charges (the negative and positive charges) and push them in opposite directions (since positive charges feel a force in the direction of an electric field and negative charges in the opposite direction). This exposes bare charges at the opposite surfaces of the spheres which themselves produce an enhanced field in the nearby region: physicstoday.scitation.org/action/showOpenGraphArticleImage?doi=10.1063/1.3554315&id=images/medium/1.3554315.figures.f1.gif If the electric field was constant and unchanging that's all it would do, it would slightly separate the two enhancing the field nearby. However because you have light, an electromagnetic *wave*, and not just a constant field, the field is constantly changing in time and it actually drives this separation back and forth like an oscillating spring system (specifically like a "forced oscillator"). Force oscillators this have special harmonic resonances and that resonances depends on the "stiffness of the spring" which in our case depends on the electrical properties of the surrounding fluid. This is what creates the various resonance effects. Of course that's a very brief and vague description, sorry. The third video will have a lot more detail and illustrations. I'm working on it! :)

[@nvspraneeth901]

but i could not find your 3rd part

[@ywk7282]

Thanks for the video. I have one question may I ask what is the difference between the plasmon and quantum dot?

[@danielpetka446]

4:32 is it possible that this happens because wavelength is constant

[@atomsandsporks6760]

Do you mean that frequency is constant when you pass through different mediums (wavelength isn't, it changes)? Actually, I'm going to probably do the third part quite soon, where I talk about the physics but in a nutshell the reason for the effect is because the electric field of the light pushes free charges in the metal back and forth and back and forth with its electric field and the so-called dielectric constant of the surrounding medium actually effects the strength of the "restoring force" the metal exhibits when face with being pushed around. If that sounds vague, apologies, there's a character limit on comments but a full video explaining should be out within a few weeks.

[@im.meer-asif]

wow, working on plasmonics on future terahertz devices

[@mohammadsadeghnamnabat263]

literally cool

[@salmantariq3420]

dud!! Awesome stuff

[@andrewkos]

Good stuff

[@convictednotconvinced]

Love your vids. You're giving a curious dummy a chance to learn physics.

[@DanielaValeriaMariadaConceicao]

Nice

[@nadac1533]

where is the third part?

[@atomsandsporks6760]

It's coming... eventually... I didn't want to become the "nanoplasmonics guy" so I held off on it. But I *will* get to it eventually.

[@ME-ru4hv]

Great video. What might happen if these metallic particles were put into the bloodstream?

[@atomsandsporks6760]

Well the idea is to generally use "noble" metals like silver and gold which are biologically inert. So one would hope nothing would happen.

[@stewartbrands]

ain't?

[@kevinmathewson4272]

i'm so sick of elon musk and his dumb tweets

[@ROOPIEF]

It's in the vaccine....