What ever happened to nanotechnology? Seems like it disappeared.

It’s still here, but you aren’t seeing it because it’s really small.

it's nanowhere
- God damn that got me good!
It wasn't a big deal after all
That's exactly what my ex wife said.

It's used in medicine, meta materials, and physics everyday.

This. You just don’t hear the word anymore. For example, it was instrumental in producing the COVID-19 vaccine.
The reason pencils work as well as they do is because of the way they are constructed, of nanomaterials.
- Graphite is now a nano material?

it didn't disappear, just got to small for you to see 😉

Damnit, stole my thunder.
- Mine too! Reddit moment where we all think we're original.
Should still be somewhere. Maybe in the carpet or the sofa...

It is still around, only the buzz around it died

I'm no nanotech scientist, so I won't pretend I know all of the ins and outs here, but I'm sure when most people think about nanotechnology, they're probably picturing something like the later generation iron man suit from the marvel movies made up of billions of tiny nanobots that can reconfigure themselves and such. If such things will ever be possible, they're still a long way off

I have a hunch you probably have some visions in your head of tiny robots similar in size to a red blood cell swimming around in someone's blood stream, that seemed like a trope that was used by a few different sci Fi series when I was growing up, and certainly the kind of thing I personally picture when I think of nanobots. Problem is, at the nano scale, those kinds of things are kind of huge, a blood cell is a few thousand nanometers across. Most of what we're doing with nanotechnology is just a handful of nanometers in size, at the scale of a few molecules or even atoms. Eventually we may be able to put some of those parts together to make tiny robots and computers and such, but right now we're still kind of figuring out how to make the nuts and bolts and gears and such to make those bots out of.

There's also a lot of nanotech research that you may not really think of as technology but more as something like material science or chemistry. Any time you hear about new developments with carbon nanotubes or graphene, that's nanotechnology. Practical applications for stuff like that are still mostly works in progress, we're probably years, decades, maybe even centuries out before some of those things really come into their own, but when we do work out the bugs, they will absolutely be revolutionary.

But it's not all far future stuff, it's almost guaranteed that you have used and maybe even have in your home or on your person right now something that makes use of nanotech in some way. One example I saw mentioned a lot is sunscreen, there's a lot of sunblock that makes use of zinc oxide and/or titanium dioxide nanoparticles, clothing may contain nanoparticles to help with things like waterproofing, reducing odor, etc. there's lots of mundane nanotech that you're probably already taking advantage of.

As a nano engineer, youre 100% right - with the added slowdowns of safety research. Many of these particles are entirely different beasts on a nanoscale, an example commonly used is microscopic copper is just copper, nanoscopic will have you dead within the hour if inhaled (dont quote my timeframe on that one).

That being said many cool materials are still coming out, just aren't yet at that commercialized availability level yet.

For example graphene has the potential to replace copper -at least in high performance applications- cause its got some fucked levels of conductivity

Edit for some more examples cause I'm a nerd about this stuff:

Carbon nanotubes make vantablack, the material that can absorb 99.9% of visible light (not that exciting beyond a party trick commercially, but in areas trying to minimize electromagnetic noise this is revolutionary).

Silver nanoparticles have been shown to have passive disinfectant properties, leading to the possibility of a cloth that you could run dirty water through and make it drinkable.

And my favorite being we've already created the carbon based structures (can't recall if it was nanotubes specifically) with theoretically high enough tensile strength that if made a couple kilometers long could be used to lasso an asteroid and create a space elavator
- About the space elevator thing, even with mystical materials, it'd need to be 110.5km long with a counterweight. Assuming it could work at all on Earth (it can't, but let's assume it can) the amount of material required would be insane. I can't find where anyone has calculated the mass of carbon nanotubes needed, but I'm sure it's out there.
  
  Assuming the material issue is solved somehow though, it's still going through the atmosphere. How does it handle those forces? It's untenable to have on Earth. It's possible on the moon, which would also require much less material since it has less mass.
Nanotubes and graphene themselves had a deep hype cycle. They're super strong... as long as they're atomically perfect. The second bit just kind of got left out of the popsci stuff circa-2009.

The biggest thing about technology nobody talks about is manufacturing. The physics was there to design a modern GPU in WWII, it's just that reliably making a thing with few-hundred-atom switches starting with 1940's tools is a very hard problem. The correct approach to do so wasn't even clear until the 70's or so, and then it took many decades of finetuning and building up ever larger and more expensive fabs that can print features that small in environments that perfect.

There's no clear way to place individual atoms of a large object at reasonable price right now. Maybe some kind of biotech will make it possible eventually, or just scaling up current atomic manipulation techniques a lot, but for now CNTs are but high-tech asbestos.

I mean... you're surrounded by trillions of perfect nanotech devices. They're called MOSFETs, and they make literally the entire modern world go round.

It became normal and normal is boring.

Booo, get out of there with reasonable and grounded explanations!
- I mean, most of the magical uses haven't materialised. Computers are better, that's about it. It has a few other commercial applications, but they're indistinguishable from normal chemistry from a laymen's perspective.

I'm not sure which era you're talking about exactly. Graphene and carbon nanotubes can't currently be made both big and perfect, and are lame when imperfect. Nanoscopic robots have problems with sticking together and jumping around due to brownian forces, and also are just very hard to build. Chemical-based robotics has been a crapshoot because quantum chemistry is hard. The last one has been tackled with machine learning pretty well recently, where natural biological analogues exist.

As a result, about as far as we've gotten is nanoscopically fine dust. It has uses, but it's only a technology the same way pea gravel is. It's looking like a lot of the stuff nanobots were supposed to do is going to fall to biotech instead.

Love the phrase "quantum chemistry is hard" because it makes it sound as if it's difficult for the average person, but I can only imagine it means that the smartest people alive are struggling with it haha.
- Some Stephen Hawking level intellect is currently in a basement acting like an angry Jim Carrey because his math just chooses not to work.
- Even worse. It's possible some of it can't be done with any reasonable amount of classical computation at all, regardless of skill or knowledge. Quantum computers are badly overhyped, but that's one thing they could definitely be good for.

Micro-electro mechanical systems (MEMS) are extremely successful. You have them in your phone and lots of other devices. It turns out semiconductor manufacturing techniques could be leveraged to make some useful devices but that is about it. There is obviously a lot happening at these scales in biology, semiconductors, materials science etc but the grey goop of nanobots turned out to be a fantasy based on extrapolations that don't seem to hold up well with physical materials thankfully. One less thing to worry about. Now we only have climate change, pathogens, war etc. Hopefully the machine learning bubble will blow over in a similar fashion, genuinely revolutionary in some areas but increasingly difficult/uneconomical to scale into others.

The sophon are stopping nanotechnology from making progress #3bodyproblem

Stop us harder, san-ti. 🥵

nanotechnology was supposed to be the most super amazing thing ever.

Like blockchain, 3d-printing, cloud and machine learning?

I feel like passionately arguing with you about 3 of your 4 examples
- It would be possible to argue about all of them, as each has genuine use cases. Just not to the extend they were praised during the hype.
- I'd like to argue why 3 of the 4 are absolutely amazing
Don't forget AI!

Totally replaced by the most super amazing AI ever

It's too small to be used by the average human being, which is why you don't see it anymore.

It's also too small to be seen by the average human.
- Oh right. I guess you need a microscope too.

The Gartner Hype Cycle

So we're on the slope of enlightenment with nanotech, probably just past the peak with neural nets, and maybe right in the trough with cryptocurrencies. (The latter are up right now, but prototype tech Bitcoin still leading the pack tells me we haven't arrived at any kind of balanced perspective)

While we're at it, how about cybernetics, too?

We can literally give sight to the blind, hearing to the deaf, and make the lame walk again.

We also have the very cyberpunk distopian problem of people being left with implants that are no longer supported by the manufacturers [2] [3]
- At least we don't need Neuropozyne (Deus Ex).
  
  Btw, what happened with the nanotubes-coated contacts that neurons are all too happy to connect to?
Prostetics have gotten extremely advanced in the last 20 years. People are controlling and getting real feedback from replacement limbs.
- Yeah, both nanotech and cybernetics are everyday things. Still very expensive, but both have mostly reached enough milestones that they go by whatever their more specific puposes are. Like prothetics with feedback aren't called cybernetics because cybernetics is too broad a term.
- Unfortunately, even our most advanced ones are more limited than a lot of people think and have a high rejection rate of around 44% that's never talked about. Some do genuinely like them, but many say they still prefer the relatively simple body powered prosthetics, or none at all.
  
  This could change as advancements are made, but as of now they're a bit of a scam.