Small MachinesHow to Make Them


By a machine, I mean things that have movable parts you can control, that have wheels and stuff inside. You can turn the movable parts; they are actual objects. As far as I can tell, this interest of mine in small machines is a misguided one, or more correctly, the suggestion in the lecture "Plenty of Room at the Bottom" that soon we would have small machines was certainly a misguided prediction. The only small machine we have is the one that I've passed around to you, the one that Mr. McLellan made by hand.

There is no use for these machines, so I still don't understand why I'm fascinated by the question of making small machines with movable and controllable parts. Therefore I just want to tell you some ideas and considerations about the machines. Any attempt to make out that this is anything but a gamewell, let's leave it the way it is: I'm fascinated and I don't know why.

Every once in a while I try to find a use. I know there's already been a lot of laughter in the audiencejust save it for the uses that I'm going to suggest for some of these devices, okay?

But the first question is, how can we make small machines? Let's say I'm talking about very small machines, with something like ten microns (that's a hundredth of a millimeter) for the size of a motor. That's forty times smaller than the motor I passed aroundit's invisible, it's so small.

I would like to shock you by stating that I believe that with today's technology we can easilyI say easilyconstruct motors one-fortieth of this size on each dimension. That's sixty-four thousand times smaller than the size of McLellan's motor, and in fact, with our present technology, we can make thousands of these motors at a time, all separately controllable. Why do you want to make them? I told you there's going to be lots of laughter, but just for fun, I'll suggest how to do itit's very easy.

It's just like the way we put those evaporated layers down, and made all kinds of structures. We keep making the structures a little thicker by adding a few more layers. We arrange the layers so that you can dissolve away a layer supporting some mechanical piece, and loosen the piece. The stuff that you evaporate would be such that it could be dissolved, or boiled away, or evaporated out. And it could be that you build this stuff up in a matrix, and build other things on it, and then other stuff over it. Let's call the material "soft wax," although it's not going to be wax. You put the wax down, and with a mask you put some silicon lumps that are not connected to anything, some more wax, some more wax, and then silicon dioxide or something. You melt out or evaporate the wax, and then you're left with loose pieces of silicon. The way I described it, that piece would fall somewhere, but you have other structures that hold it down. It does seem to me perfectly obvious that with today's technology, if you wanted to, you could make something one-fortieth the size of McLellan's motor.

When I gave the talk called "Plenty of Room at the Bottom," I offered a thousand-dollar prize for the motorI was single at the time. In fact, there was some consternation at home, because I got married after that, and had forgotten all about the prize. When I was getting married, I explained my financial position to my future wife, and she thought that it was bad, but not so bad. About three or four days after we came back from the honeymoon, with a lot of clearing of my throat I explained to her that I had to pay a thousand dollars that I had forgotten aboutthat I had promised if somebody made a small motor. So she didn't trust me too much for a while.

Because I am now married, and have a daughter who likes horses, and a son in college, I cannot offer a thousand dollars to motivate you to make movable engines even forty times smaller. But Mr. McLellan himself said that the thousand dollars didn't make any differencehe got interested in the challenge.

Of course, if we had these movable parts, we could move them and turn them with electrostatic forces. The wires would run in from the edges. We've seen how to make controllable wireswe can make computers, a perfect example of accurate control. So there would be no reason why, at the present time, we couldn't make little rotors and other little things turn.




Nanotechnology. Science, Innovation, and Opportunity
Nanotechnology: Science, Innovation, and Opportunity
ISBN: 0131927566
EAN: 2147483647
Year: 2003
Pages: 204

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