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Making Microelectronics Out of Nanodiamond
Science_afficionado writes "Electrical engineers at Vanderbilt have created the basic components for computer chips out of thin films of nanodiamond. These combine the properties of vacuum tubes and solid state microelectronics and can operate in extreme environments where normal devices fail."
Don't turn the ring down. All the best electronics are made out of diamonds this size.
The first semiconductor transistors were large enough to handle a single one with your hand. What makes you assume that the nanodiamond transistors cannot get smaller?
The Tao of math: The numbers you can count are not the real numbers.
"Potential applications include military electronics, circuitry that operates in space, ultra-high speed switches, ultra-low power applications and sensors that operate in high radiation environments, at extremely high temperatures up to 900 degrees Fahrenheit and extremely low temperatures down to minus 300 degrees Fahrenheit."
Why not use this design for consumer products? All the way around it's a better design. I'd cough up a few bucks more for this chip.
I wonder how you distinguish femtodiamonds from femtographite, though.
A really tiny jeweller's loupe?
Blank until
Each individual feature is just too big. You're looking at individual transistors 20x or more larger than what we have today on silicon. Faster and lower power, maybe, until you try and build a working CPU from them and discover you need a die 3cm x 3cm. Niche products only.
Here is the clincher:
The nanodiamond circuits are a hybrid of old fashioned vacuum tubes and modern solid-state microelectronics and combine some of the best qualities of both technologies
Just as soon as the audiophile industry hears about this they'll go batshit insane. Something that is 1) new 2) expensive 3) combines tubes and anything else will be simply irresistible to them. Bonus points for diamond covered wooden knobs.
Faster! Faster! Faster would be better!
The funniest thing about the Time Cube guy is he's actually 100% correct, there are four days in each day. In fact, there are 24 (timezones) 'days' on the earth in each day. To be more precise, there are an infinite number of days in each rotation of the earth, depending on where you start.
I've always wanted someone to saw off the corners of one of those cubes, so it has eight sides, and send it to the guy. See how it blows his mind. Time Octagon.
"First they came for the slanderers and i said nothing."
You can't make vacuum devices with holes, so there are not the complementary devices needed for CMOS like operation. We would be working with a technology similar to N-channel FETs, with all the problems of low-output state power dissipation. It won't scale to high integration levels. That said, the technology probably has niche applications in high temperature and rad-hard environments.
The extreme temperatures/radiation niche is a real and valuable one, particularly as these devices will cost a fortune at first.
Also, the 8-bit CPUs of thirty years ago should be quite feasible. From there, we'll see what can be squeezed out of physics ...
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I did research on this stuff back in the 1990s. Made the films, did the vacuum chambers, had the world record for emission efficiency for a while. While it may have some niche applications, the basic problem is that it is *not* a low-voltage technology. Modern chips operate on 1.5 V or so; Diamond devices will be more like 5V. So ultra-low power? Nope. They say that the devices are more efficient because the electrons don't bump their way through the silicon crystal lattice. While that's true enough, it doesn't actually make a big difference. Why? Because the electrons very much will dump all their energy when they leave the vacuum and hit the anode.
Ultra-high speed? Again, while vacuum is nice in that it doesn't slow down the electrons, that turns out not to be a big effect. The most important factor in speed is the size of the device, and there is certainly no reason to believe that these vacuum tubes will be smaller than transistors, if built with the same lithography tools. I may be wrong, but I have good reasons to believe that they will be harder to make small.
High temperature? Radiation resistance? Maybe, but that turns out to be a complex question. These devices aren't just diamond and vacuum. They involve insulating layers, too, and those insulators may be affected my high temperatures or radiation. Essentially, a device is as robust as its weakest link, so until you can make the entire device out of truly robust materials, you won't gain too much.
So, it's nice work. I know how hard it is to do this stuff. And, it might be useful eventually. But it won't revolutionize technology any time soon. And, those guys ought to realize that, if they would let themselves. Research lives off publicity these days, because it is being forced to become more and more of a competition between groups. The trouble is, when competition enters and your salary depends on the claims you can make, truth tends to be (shall we say) over-inflated.
That darn free market ideology messes up science. I like it as much as anything for people who make spoons or telephones. But science isn't making spoons. If you get a bad spoon, you'll know it, but if you read an exaggerated research paper, how can you tell, other than by doing the research again? And, that's just not efficient: doing it wrong and then doing it again isn't nearly as good as doing it right the first time.
Oh well. Enough ranting.
You and the GP are both misunderstanding "digital" and "analog". The first digital computers used vaccuum tubes; the first digital computer was patented in 1946. The first useable transistor was made in 1954 (wikipedia article on transistors).
"Digital" usually refers to computers using the binary number system, while analog refers to circuits using an analogy; a potentiometer is an analog component. Transistor radios were analog circuits, and in the 1960s there were analog computers using transistors. In fact, you can construct an analog computer using nothing but a battery, two potentiometers, and an analog voltmeter, although it's really more of an electric slide rule than a computer. But there were sophisticated analog computers that would actually use fractions rather than binary math which output to a CRT (CRTs are tubes, too).
Tubes and transistors both serve pretty much the same purpose. The biggest difference (aside from size) is transistors can handle physical shock without harm, while tubes can handle high temperatures and voltages without harm. Tubes break, overheat or electrically overload a transistor and it will "break".
You can fit a building full of vacuum tube circuits in a single integrated circuit. That computer on your desk would take acres, even square miles, of vacuum tubes to perform the same function.
Nanotech promises even smaller scales. This diamond tech sounds like it could provide the benefits of both tubes and transistors (which work completely different from each other).
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Just as soon as the audiophile industry hears about this they'll go batshit insane. Something that is 1) new 2) expensive 3) combines tubes and anything else will be simply irresistible to them.
I know, you jest, but judging from TFA they're only talking about the diamond transistors being able to withstand heat like tubes do.
Musicians use tube amps because tubes overload differently than transistors; the wave distortion is different. Overload a transistor or a tube with a sine wave and both will produce a square wave, but the tube's "square wave" will have rounded corners while the a transistor will have the top chopped off cleanly, making it more like a true square wave.
However, you're right about one thing -- audiophiles are gullible.
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The first semiconductor transistors were large enough to handle a single one with your hand. What makes you assume that the nanodiamond transistors cannot get smaller?
There are unfortuantly some additional physics problems that need to be address for miniturization of this technology.
One issue is the free-space electron transport. With silicon technology, the "channel" is doped silicon which carried the electrons (like a wire). The channel sort of acts like a waveguide for the electrons as the travel between the source and the drain (assuming common mos technology). In "free-space" transport between the cathode and anode (vacuum tube and the proposed nano-diamond transistor), you need to keep some sort of physical separation (in an all-free-space design) or some sort of electrical isolation betweeen devices (shielding).
The second issue is the structure. In the proposed diamond design, the diamond "circuitry" is patterned so that it is essentially carved to have structures above the silicon dioxide surface (as opposed to standard patterning which is either directly on the surface ion implated into the substrate). This nano-tech like structure will of course need to scale to get better. If they can take anything from the current silicon technology, shrinking in 2D (patterning) is much easier than shrinking in 3D (needed for reduced gate thickness needed to improve gate channel efficiency). In advanced silicon technology, 3D scaling has be all but abandoned in favor of techniques like tri-gate/fin-fet...
Note that I'm not saying these advances aren't possible, but they do not leverage any current manufacturing techniques, so it's likely that this stuff will be in the lab for a while whilst current technology will advance. When it does become feasible, it may or may not be competitive. This is not unlike ferro-magnetic ram might replace dram someday, or how solid state memories will replace rotating disk memory someday... Maybe someday, but it's equally possible that day may also never come or be so far out that other new technologies may gain a foothold (e.g., how RRAM might actual displace FRAM as the DRAM successor)...
As a silly example, if you invested the same amount of "area" in some farady-cage-like shielding of present day CML (current-mode-logic) technology electronics, would this nano-diamond technology be much better? I dunno, but these new-fangled technologies need to beat these kind of tweaks of current day technology to win. But of course we have to both try to do new things and try to improve old things and see which one comes out on top. However to assume that the appropriate technological and manufacturing advances will necessarily come to pass to make a general approach viable would be a mistake as a heap load of abandoned technologies will certainly attest to...
Shine on, you crazy benzine?
(Damn, if that ain't a nerd joke I don't know what is)
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I remember reading about this kind of thing in the mid 1990's. Scientific American reported on it. At the time, they were making diamond films on ceramic substrates. the diamond was grown by creating a carbon atom plasma and shooting it at the substrate. Shock plasma deposition of the carbon. It wasn't very efficient. They hadn't worked out too well how to mask and etch the films, so they were using electron beams tp cut into the diamond, then adding the dopant. That limited the size of the device produced. The device was around the diameter of a pencil eraser. The researchers (in Japan, if I remember correctly) were predicting commercial development in as little as five years. Well, I never saw anything come of it.
I was looking forward to that coming out too. I am an electrical engineer, and have worked for a long time with plans for building facilities and power lines and so forth. The device made in Japan was a single SCR (silicon controlled rectifier) that would work just fine at 600 Volts, and a little over 200 Amps. It operated at a temperature of a little over 600 degrees C, but still, an SCR can be used for many power applications. That single SCR was controlling a around 120KW. For big AC to DC power lines, we use SCR banks where each of the SCRs operate at about 24 Volts relative to the next SCR in the stack. This for stacks that go up to 750 KV. The stacks are paralleled to get the current that actually goes out over the line. One such line goes from Washing State to LA, and carries close to 10% of the total power used by LA. for what I was doing at the time. These diamond SCRs would have made a great speed control motor starter. At 480 VAC, we could have made the controller with six SCR's, three fuses, and a disconnect switch, plus a small PLC board. The control station would be bigger than the controller. Typical controllers for this type of application on say a 100 HP motor are around 7 feet tall, 4 to 10 feet wide and 3 to 6 feet deep. reducing this to 2 Feet wide, 3 feet high and 1 foot deep would free up a lot of space. This, if purchasable, would have given me a lot more freedom in placement. If I could reduce the size of the controller, the process people would have loved to use the extra space. I could have used that to justify spending up to $100,000.00 more for the device, in some cases.
We could really use such a device in industry. There are a ton of uses that I could think of off the top of my head. Used as an ultracapacitor controller, it would enable a single capacitor, the size of a couple of C cell batteries to store more power than a car battery. A large electronically controlled circuit breaker, with custom controls, and a quick action would also help to save a lot of equipment and lives.
There were a couple of real problems with it, though. First, it's flammable. The actual electronics would need to be isolated from any contact with oxygen. Encapsulation would do that. Real Graphene computer chips, which I would expect to see before this matures, would also be flammable. But, there are more options for protecting those, because of the relatively lower temperatures.
Also, the Diamond SCR's operated at temperatures higher than some common conductors can withstand, and well above the temperature at which Diamond burns. There would have to be special connectors, and cooling systems. That heat, even if from a small eraser sized element needs to go somewhere. Ultimately out into the environment.
Second, it's apparently not an easily commercialized process or material. I am seeing more reports of Diamond film growth, and also of graphene film growth and production. That is a good thing. Graphene seems to be moving towards fabrication faster than diamond. I would like to see both happening. I have also seen recently, that very low impedance conductors have recently been made from carbon nanotubes. While not room temperature superconductors, if they have lower conductivity than copper, I would really like to be able to specify them. Cost would be a factor there. Bu
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