A great article. I suspect the shortest route to atomically-precise manufacturing will be by engineering biology since biology already knows how to do it. And there is even already a high-school competition as Feynman suggested at the end of that article: http://en.wikipedia.org/wiki/International_Genetically_Engin...
I'm pretty sure that's not going to be "the shortest route," J, but it may be "a route" eventually. Samsung already produces a NAND flash chip at 10 nm. The lattice spacing in crystalline Si is about 0.54 nm, so we're talking about a transistor feature size of a bit more than 18 atoms. These are available on the market as we speak, and you might even be using one right now if you have a sweet new Samsung SSD.
Proof-of-concept Si FETs have been made down to around 3 nm, last time I checked, or around 6 atoms. Grossly speaking, these are essentially refinements of photolithographic CMOS processes. Soon we'll hit a wall with this, but for now, I think atomically-precise manufacturing is already pretty achievable without engineering biology.
Biology does not do atomically-precise manufacturing. It does do a lot of sorting and filtering of random interactions, and in a few places (the ribosome), precision alignment of large complex basic units (amino acids). It is very, very unlikely that we will develop Drexlerian nanotech via biological processes.
Greg Egan speculates on femtotechnology in some of his sci-fi, mostly as insanely fast computers. (I mean, jeez, it takes SO MUCH TIME for an electron to whirl around the nucleus of an atom... it's so much faster when your computer is the nucleus.)
As a physicist and mechanical engineer ... I have absolutely no idea how femtotechnology is supposed to work. The entire premise seems to be: "quarks are smaller!" So? You know what you get when you put a bunch of sub-atomic particles together? Atoms.
I would like very much to see an actual femtocomputer design, one which has a chance of working (as a commentator in the h+ article points out: "Unfortunately, this relies on assumptions that contradict known physics and ones that have not yet been proven."), so I could at least understand what it is supposed to be...
And we are almost there. People currently print circuits with 18nm features, that's about 180 atoms long, or a square with 32 thousand atoms in the surface. We are still limited to planar designs on silicon, but that's just a couple of breakthroughts from 3D printing once we get precision enough.
But that's the talk that launched the idea of molecular nanotech. That side note is far away (or not, who knows?), but the main line is almost here.
Chips are built differently from your standard 3D printing process: 3D is additive or subtractive, while chips are mask-deposit-strip (filter, additive, subtractive?). Keep in mind that the reason we can get to those sizes on microchips is through mind-boggling optical engineering on the masking step. I remember a prof explaining in the clean room over one of our Perkin-Elmer lithography stations that it takes years to redesign the systems for new wavelengths; the application's precision demands that each optical system is specifically engineered and tailored to that wavelength.
Get rid of the masking stage and you've got the missing link to 3D printing. But that would require nigh magical levels of control over a particle beam. Which could totally be solvable to a sufficiently clever team of engineers and a sufficiently robust and controllable beam source. But add that basically nothing behaves itself on those scales, especially machines, and there's still tons of work left.
But you're right like Feynman was all those years ago: you can totally imagine it is plausible, so there's no way we won't try! (Great, now I want to go back into microtech...)
To point out what everyone's overlooking: this was written in 1959, which means the wildest sci-fi nanotechnology he's imagining here... is, basically, achieved by magnetic HDDs since around 2011.
"Why cannot we write the entire 24 volumes of the Encyclopaedia Brittanica on the head of a pin?"
"Let's see what would be involved. The head of a pin is a sixteenth of an inch across. If you magnify it by 25,000 diameters, the area of the head of the pin is then equal to the area of all the pages of the Encyclopaedia Brittanica. Therefore, all it is necessary to do is to reduce in size all the writing in the Encyclopaedia by 25,000 times. Is that possible? The resolving power of the eye is about 1/120 of an inch – that is roughly the diameter of one of the little dots on the fine half-tone reproductions in the Encyclopaedia. This, when you demagnify it by 25,000 times, is still 80 angstroms in diameter – 32 atoms across, in an ordinary metal. In other words, one of those dots still would contain in its area 1,000 atoms. So, each dot can easily be adjusted in size as required by the photoengraving, and there is no question that there is enough room on the head of a pin to put all of the Encyclopaedia Brittanica."
By his assumption, a pinhead is about 0.003 inches^2 (2 mm^2). The current Encylopedia Brittanica has about 300 million English characters [0], which is about 300 MB in a reasonable text encoding (although it should compress [1] to around 60 MB). So, what Feynman is speculating about, translates in digital language to a memory density of 300 MB/(0.003 in^2) or 100 GB/in^2 or 800 Gb/in^2. This is roughly an average magnetic HDD from 2011 [2].
To emphasize the point: Feynman is speculating about a dot "80 angstroms [8 nanometers] in diameter - 32 atoms across, in an ordinary metal". This is actually the size of a magnetic domain on a HDD platter -- wikipedia gives it as 10 nm [3].
Unfortunately, there now exists a far larger English-language encyclopedia which is 9 GB compressed [4] or 75 GB with images [5]. Using Wikipedia as the new benchmark, it is currently not possible to compress it onto the head of a pin.
[+] [-] jrkelly|12 years ago|reply
[+] [-] lvs|12 years ago|reply
Proof-of-concept Si FETs have been made down to around 3 nm, last time I checked, or around 6 atoms. Grossly speaking, these are essentially refinements of photolithographic CMOS processes. Soon we'll hit a wall with this, but for now, I think atomically-precise manufacturing is already pretty achievable without engineering biology.
[+] [-] maaku|12 years ago|reply
[+] [-] IvyMike|12 years ago|reply
https://en.wikipedia.org/wiki/Femtotechnology
Greg Egan speculates on femtotechnology in some of his sci-fi, mostly as insanely fast computers. (I mean, jeez, it takes SO MUCH TIME for an electron to whirl around the nucleus of an atom... it's so much faster when your computer is the nucleus.)
An excerpt from a Egan short story: http://gregegan.customer.netspace.net.au/SCHILD/00/SchildExc...
More on femtocomputing: http://hplusmagazine.com/2011/11/01/femtocomputing/
[+] [-] maaku|12 years ago|reply
I would like very much to see an actual femtocomputer design, one which has a chance of working (as a commentator in the h+ article points out: "Unfortunately, this relies on assumptions that contradict known physics and ones that have not yet been proven."), so I could at least understand what it is supposed to be...
[+] [-] T-A|12 years ago|reply
[+] [-] marcosdumay|12 years ago|reply
But that's the talk that launched the idea of molecular nanotech. That side note is far away (or not, who knows?), but the main line is almost here.
[+] [-] HCIdivision17|12 years ago|reply
Get rid of the masking stage and you've got the missing link to 3D printing. But that would require nigh magical levels of control over a particle beam. Which could totally be solvable to a sufficiently clever team of engineers and a sufficiently robust and controllable beam source. But add that basically nothing behaves itself on those scales, especially machines, and there's still tons of work left.
But you're right like Feynman was all those years ago: you can totally imagine it is plausible, so there's no way we won't try! (Great, now I want to go back into microtech...)
[+] [-] maaku|12 years ago|reply
[+] [-] petergreen|12 years ago|reply
I so want to make and have this tiny car and give mites driving permits omg.
[+] [-] T-A|12 years ago|reply
[+] [-] throwaway_yy2Di|12 years ago|reply
"Why cannot we write the entire 24 volumes of the Encyclopaedia Brittanica on the head of a pin?"
"Let's see what would be involved. The head of a pin is a sixteenth of an inch across. If you magnify it by 25,000 diameters, the area of the head of the pin is then equal to the area of all the pages of the Encyclopaedia Brittanica. Therefore, all it is necessary to do is to reduce in size all the writing in the Encyclopaedia by 25,000 times. Is that possible? The resolving power of the eye is about 1/120 of an inch – that is roughly the diameter of one of the little dots on the fine half-tone reproductions in the Encyclopaedia. This, when you demagnify it by 25,000 times, is still 80 angstroms in diameter – 32 atoms across, in an ordinary metal. In other words, one of those dots still would contain in its area 1,000 atoms. So, each dot can easily be adjusted in size as required by the photoengraving, and there is no question that there is enough room on the head of a pin to put all of the Encyclopaedia Brittanica."
By his assumption, a pinhead is about 0.003 inches^2 (2 mm^2). The current Encylopedia Brittanica has about 300 million English characters [0], which is about 300 MB in a reasonable text encoding (although it should compress [1] to around 60 MB). So, what Feynman is speculating about, translates in digital language to a memory density of 300 MB/(0.003 in^2) or 100 GB/in^2 or 800 Gb/in^2. This is roughly an average magnetic HDD from 2011 [2].
To emphasize the point: Feynman is speculating about a dot "80 angstroms [8 nanometers] in diameter - 32 atoms across, in an ordinary metal". This is actually the size of a magnetic domain on a HDD platter -- wikipedia gives it as 10 nm [3].
Unfortunately, there now exists a far larger English-language encyclopedia which is 9 GB compressed [4] or 75 GB with images [5]. Using Wikipedia as the new benchmark, it is currently not possible to compress it onto the head of a pin.
[0] https://en.wikipedia.org/wiki/Wikipedia:Size_comparisons#Com...
[1] https://en.wikipedia.org/wiki/Entropy_%28information_theory%... ("1.5 bits per character")
[2] http://storageconference.org/2013/Papers/2013.Paper.01.pdf
[3] https://en.wikipedia.org/wiki/Magnetic_storage#Design ("Magnetic grains are typically 10 nm in size...")
[4] https://en.wikipedia.org/wiki/Wikipedia:Database_download#En...
[5] http://xowa.sourceforge.net/image_dbs.html
[+] [-] unknown|12 years ago|reply
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[+] [-] Houshalter|12 years ago|reply
[+] [-] popotamonga|12 years ago|reply
[+] [-] roye|12 years ago|reply