Top-Bottom & Wet-Dry

The NIST press release that we wrote about on Tuesday contained this passage:

In his 1986 book, The Engines of Creation, K. Eric Drexler set down the long-term aim of nanotechnology—to create an assembler, a microscopic device, a robot, that could construct yet smaller devices from individual atoms and molecules.

For the last two decades, those researchers who recognized the potential have taken diminutive steps towards such a nanoassembler. Those taking the top-down approach have seen the manipulative power of the atomic force microscope (AFM), a machine that can observe and handle single atoms, as one solution. Those taking the bottom-up approach are using chemistry to build molecular machinery.

However, neither the top-down nor the bottom-up approach is yet to fulfill Drexler's prophecy of functional nanobots that can construct other machines on a scale of just a few billionths of a meter.

We can picture the top-down and bottom-up dichotomy this way:

Another way to illustrate different approaches being taken toward the goal of building a nanotech assembler (which CRN prefers to call a "fabricator") is Wet vs. Dry:

Some researchers favor the "wet-nano" approach, typically using self-assembly to make structures that can mimic biological behavior while accomplishing designed tasks. Others insist that the best way to arrive at a high-functioning atomically-precise molecular fabricator is to work in vacuum, which is called "dry-nano."

But the point of this blog entry is that all these approaches -- top-down, bottom-up, wet-nano, dry-nano -- are working toward the same end point. And while it's still not clear whether one or another of them is the best way to go, as each moves forward, they are in fact coming closer to convergence.

We can't say for sure how soon, but with all of the research going on today, it seems a near certainty that desktop nanofactories (or their equivalent) will be produced within the next decade or two. CRN's biggest concern is not whether they will become a reality, but what the effects will be upon the world and its inhabitants.

Numerous environmental, humanitarian, economic, military, political, social, medical, and ethical implications of molecular manufacturing must be studied and understood. Plans must be formulated for managing this transformative and potentially disruptive new technology. All that will take time, lots of time. We'd better get to work.

Mike Treder

 

Comments

[Michael Anissimov]

Nice images, can you post links to larger versions? These would be good for a Powerpoint presentation on MNT.