Nanotech has come a long way in the last 20 yrs or so. They can build not only tiny little gears, and such, but have actually have built small mechanisms.
Nanotech has, it seems also run into a limit. Fine control of nano scale mechs is nearly impossible. Brownian motion pummles these tiny machines so severly that actually being able to steer and even move them is near impossible. Imagine trying to steer a shopping cart to your car if it was hailing basket balls. Heavily.
Certainly movement and control are not required for all nano scale operations. Materials processing, for example would actually benifit from brownian motion moving raw materials towards them, and removing processed products. Other limits come up in these situations, mostly originting in electrostatic forces (Things too strongly attracted or repelled).
Can we, and when should we expect consumer devices and applications based on Nanotech? I am betting not for a long while, if at all. If it does, my bet will be something in the cosmetics line - nano sized botox dispensers, or some such.
I should adress the lack of sites for the claims implied in this question. I feel that the subjects mentioned would be more or less familiar to those interested in current developments in Nano Technology Research.
I’ve always thought that most Nanotech ideas were ridiculous. It’s like what the Victorians thought of the future - huge machines with gears and pulleys. - instead of micro-controller based gadgets. Why make a little “machine,” when there are already objects that do almost everything we want, self-replicate, and have a proven energy source. What are these objects?
I just can’t see a nano-machine being as well designed as E. Coli.
According to Ray Kurzweil and the exponential trends he sees in miniaturization, nanotech should be large scale and mainstream sometime in the 2020s.
He did predict the internet in the 1980s due to exponential trends, saying it would arrive around 1995.
However most of his predictions of 1999 and the early 20th century are only starting to hit the market (exoskeletons to help people walk, self driving cars, translation software) while others currently exist (text to speech software, artificial telephone screeners).
If Kurzweil is any guage (I think he is mostly right, but way too optimistic in confusing research projects with reliable, mainstream technology), I’d say add 10-15 years to his predictions. So 2040.
It also depends on what you mean by nanotech. If you mean robotics and information technology the size of a bacteria, it could be decades. Nanotech for cancer or drug delivery might be a few years away.
Biological systems already are, in a very real sense, nanotech, which is very useful to keep in mind when people start making magical claims about what nanotech can do. You want to grow a bridge using nanomachines? Sure, but expect it to take as long as to grow a tree of the same size.
Well as Chronos points out life is nanaotech, and highly tuned and efficiant gray goo makers already exist in the form of decomposing bacteria and are a useful part of the ecosystem, not the end of it. Anything beyond what bacteria can do would depend on outside energy from us, and could therefor be shut off.