Fingers can detect nano-scale wrinkles even on a seemingly smooth surface | Hacker News Reader

Fingers can detect nano-scale wrinkles even on a seemingly smooth surface

sciencedaily.com

147 pointsswombat43 comments

The title is a bit misleading though. Though it would be real cool, saying we can detect molecule size pattern does not mean we could read Braille alphabet on molecule size dots. The eye can detect nanometer size patterns: we can make the difference between blue light ( radiation with a 400 nanometers wave length ) and red light ( radiation with a 800 nanometers wave length ). Does not mean we can see nanometer size objects. Bottom line, be careful talking about patterns ....

Well, we can feel bumps 13 nanometers high, as long as they are 760 nanometers long :)

We can also see a candle in complete darkness from 50 km away so just a handful of photos are enough for a sensation.

"The researchers found that the emission of only 90 photons could elicit visual experience. However, only 45 of these actually entered the retina, due to absorption by the optical media. Furthermore, 80% of these did not reach the fovea. Therefore, the human eye can detect as few as nine photons."

http://en.wikipedia.org/wiki/Absolute_threshold

As another (minor) clarification to the article, where it says:

If your finger was the size of the Earth, you could feel the difference between houses from cars

I think it would be easier to visualize this way:

If the Earth was the size of an orange, your finger could feel the difference between houses from cars

That still requires a pretty impressive feel for the relative size of oranges and planets though. I would have preferred something like this table:

  2 nm Diameter of a DNA Alpha helix

  4 nm Globular Protein

  6 nm microfilaments

  7 nm thickness cell membranes

 20 nm Ribosome

 25 nm Microtubule

 30 nm Small virus (Picornaviruses)

 30 nm Rhinoviruses

 50 nm Nuclear pore

 100 nm HIV

So 13 nm is on the scale of a very small virus... :)

Something tells me that you don't really need an analogy at all :)

A virus is 30nm? Good lord. The minimum feature size of commercial transistors is half that right now.

I like your analogy better. But it still implies that you could feel one car and one house, which you couldn't.

So, perhaps an even better analogy would be:

If the Earth was the size of an orange, your finger could feel the difference between cities and forests.

This puts more emphasis on the distinct patterns the objects form as a group, rather than the individual objects.

It's almost certainly all about the pattern.

I make telescope mirrors. The error I'm allowed is 100 nm. I would love to just drag my fingers over the glass and tell if something is not quite right with the optical surface. In reality, I need a pretty elaborate optical setup to amplify the errors about 1/2 million times, in order to see them.

I'm guessing the spatial frequency of the pattern in that experiment is on the same size scale like the vertical amplitude of it.

It is rumoured that Bernhard Schmidt had so sensitive touch, that he could physically feel polishing results by his (only) left hand.

http://en.wikipedia.org/wiki/Bernhard_Schmidt#Mittweida_year...

If this is about the early stages of polishing, I believe it (and I can do it myself).

Disney Research has done some interesting work on touch screens for the visually impaired.

http://www.olivierbau.com/teslatouch.php

One of the side benefits of this kind of tech -- for everyone, not just visually impaired -- is being able to experience otherwise untouchable objects (camera takes an image, you touch the screen instead of the object).

Interestingly enough, FastCoDesign also had an article about a bunch of these guys. One person in particular, Ivan Poupyrev who is cited at the bottom of the above Teslatouch article, is slated to move to Motorola (furthermore Google).

http://www.fastcodesign.com/3024801/motorola-just-hired-one-...

Should be fascinating what Google/Motorola will do with this relatively unknown hire of a HCI/UX guru.

In the article they talk about making sections of a smartphone's screen feel different (permanently, I assume), but would it be possible to have a type of glass where the texture of the glass can be changed quickly and repeatedly by applying some sort of magnetic/electrical field and an app could, for example, make your phone's glass feel like it has buttons, then you could switch to another app and it would feel like a different set of buttons? I'm obviously not an electrical engineer, but I'd be interested to hear more informed opinions.

Yes, that is already one of many options of haptic feedback being explored actually:

> A new technique that does not require actuators is called reverse-electrovibration. A weak current is sent from a device on the user through the object they are touching to the ground. The oscillating electric field around the skin on their finger tips creates a variable sensation of friction depending on the waveform, frequency, and amplitude of the signal.

http://en.wikipedia.org/wiki/Haptic_technology

It seems that I've got years of experience with third generation haptic technology then.

If you plugin a laptop into an outlet that is not properly grounded and move your fingers across metal surfaces of the thing, one can experience it first hand. A sensation of friction, like moving your fingers over ripples because of the current running through them. This should work with a lot of electrical appliances that have metal surfaces.

Not really pleasant though :)

Now that you mention it, I have that with my current laptop too! It has made me long for the days of plastic covers, something I did not think possible :).

I thought I was just imagining that area below the keyboard on my laptop sometimes feels rougher.

Simply put, glass is molecularly geometric - building actuated buttons into the glass itself isn't very probable. But a film of actuated buttons could be added much like with capacitive touch sensors today.

Microfluidics is near the 100nm range today. Throw in a bit of ferrofluid and something like this is at least plausible. The challenge is in making all this transparent. The microfluidic channels would need to not create a 'screen door effect' and the fluid transparent.

The Royal Society of Chemistry's 'Lab on Chip' Youtube Channel [1] is a good place to daydream about the future of such things.

[1] http://www.youtube.com/user/labonachipVideos/videos

You might also find this video [1] interesting. Although it's not clear how far this company has actually got with the technology.

[1] http://vimeo.com/43431035

@1m18s you see a syringe of fluid - so it's something similar. Maybe two laser-cut capacitive films with non-conductive fluid pumped through to make static 'buttons'. Probably a better MVP than what I suggested earlier :).

Thanks for the link.

If your target audience are the visually impaired, why do you need to make them transparent?

Totally possible Have a look at this http://tactustechnology.com/

"large molecule" is pretty misleading. DNA is single molecule and unrolled has length over 2 meters. Organic molecules are practically unlimited in their size.

Do you have a source on that? It didn't gut check with me and some quick googling turned up some contradictory, but not decisive, information otherwise [1]

1. http://wiki.answers.com/Q/What_is_the_size_of_a_DNA_molecule

http://www.biology-online.org/biology-forum/about819.html

Fourth post on the page gives a source: This is from Molecular Biology of the Cell (4th Edition) 2004. Alberts et al. Textbook. "Each human cell contains approximately 2 meters of DNA if stretched end-to-end"

Perhaps a human cell contains several DNA molecules?

Each human cell typically contains 23 chromosomes, each of which is basically a long DNA strand.

This indicates that the total length unraveled is 2m: https://www.inkling.com/read/essential-cell-biology-bruce-al...

technically correct but they are talking about touching the accessible surface of a compact molecule which is approximately spherical and thus "size" is determined by its raised profile on a surface.

That's very interesting, considering our smallest nerve-cell -I believe- is about 4 ųm.

I'm disappointed the article doesn't mention the significance of age, or even the average age of the study.

We all just ran our fingers over our desk/keyboard/pants.

Brilliant observation. Yes, on my Desk. :)

The silicon spheres for the Avogadro project were polished by a single Australian guy.

From Wikipedia (http://en.wikipedia.org/wiki/Kilogram#Avogadro_project):

These spheres are among the roundest man-made objects in the world. If the best of these spheres were scaled to the size of Earth, its high point—a continent-size area—would rise to a maximum elevation of 2.4 meters above "sea level".

^ that IS impressive ^

My experience with machining fittings was that I could see a gap of 100 um and I could feel a step of as low as 10 um. This was also the limit of the machining and measurement equipment, so I don't know if I could have felt smaller steps.

Machining gave me a sense for dimensions in the micrometer range. I think of 1 um = 1000 nm = near infrared, visible light ends at 800 nm. It makes the phenomenon of light somehow tangible.

When making nanocubes, you could still resolve that they were square even at 100 nm with an ordinary light microscope, which was a surprising (yet kind of obvious in hindsight) discovery for me.

This does make me wonder if it would've been possible to feel them.

Maybe I'm missing something, but I think physics prevents this. An excellent lens has a numerical aperture of maybe 0.95 at best, so with Abbe's formula you get a resolution limit of maybe 200 nm at best. With an oil immersion microscope (still a light microscope, albeit not an ordinary one) you might get as low as 100 nm, but that doesn't mean you could see that fact that the tubes are square. It's a long time since I've heard physics and that I've been in an laboratory, so maybe I'm wrong.

No you are right - I kind of buried the lead there. The cubes themselves have a side-length of 100-120nm, but it means the longest diagonal length is actually more like ~211nm.

But there's also the 2D diagonal which is 172nm, so what seems to happen is you end up seeing two slightly super-imposed and different shaped blurs, whereas normally you'd see just the 1 if they were perfect spheres.

This article is completely overstated. People have been measuring this for decades. Look up the work of Mountcastle or Bensmaia on somatosensation and vibrotaction. Most of what we perceive down at the nm scale is differences in frequency with which our skin vibrates when we run our finger across a surface, we even have the spikes from peripheral nerves that show the differences in textures.

That is until you learn to play the guitar

I can feel subtle differences with small finger movements on cello. It's actually really fun really high up on the instrument, as the notes are super close together, and you can make extremely microscopic movements that affect the pitch/sound!

paper : http://www.nature.com/srep/2013/130912/srep02617/pdf/srep026...

Can someone suggest a molecule I might of heard of that is 13nm in size?

http://htwins.net/scale2/

Zoom in and you can get an idea.

Transistor feature sizes in commercial products are no smaller than 16nm right now. Wow.

Reply on news.ycombinator.com