Sunday, November 8, 2009

SU Exec Program day 2: Intro to Nanotech, Ralph Merkle


"If you rearrange the atoms in coal, you get diamond. If you rearrange the atoms in sand, you get silicon. How atoms are arranged is fundamental to all material aspects of life," says Ralph Merkle, currently senior research chair at the Institute for Molecular Manufacturing. He's a large, pear-shaped man who, as he speaks, waves his arms far more energetically than his physique would imply. He modulates his tone dramatically for effect, often humerous.

Those words kick off day 2 at the SU Exec Program. The curriculum divides roughly into three days of intensive classroom introductions to critical tech domains, three days of visits to Silicon Valley companies, and two days of workshops devoted to specific industries, plus a final day to wrap up. Yesterday I settled gingerly into a lightly padded metal chair for highly compressed, sometimes super technical, up-to-the-minute overviews of artificial intelligence, robotics, networking, computing, and quantum computing. (Forecast: sunny! With patchy clouds and fog.) That took until dinner time with only a quick break for lunch, which was filled with presentations by graduates of SU's nine-week summer program.

Merkle differentiates between "linear nanotech" like stain-resistant textiles and the real thing: molecular machines first suggested by physicist savant Richard Feynman. "We can arrange atoms in most of the ways permitted by physics," he says, showing a slide of a tabletop molecular assembly machine that can make "pretty much anything you want." Can we get that far? "We can get at least that far."

From there he skims through a catalog of progress - familiar example of pushing atoms into IBM logos and such on a 2D grid - to the goal of 3D shapes, and ultimately nanoscale machines. It doesn't always work. "You're not seeing the failures," he allows, and describes a planetary gear he built that was just too slippery to hold together. "There's no friction at that scale." Moreover, that style of assembly is one atom at a time - very resource-intensive. A better solution is self assembly, along the line of, say, a redwood tree - a huge structure self-assembled by nanomachinery. If we can accomplish that, "manufacturing costs will go through the floor." Products of nanomachinery will be as cheap as potatoes.

The notion that nanotech will provide new materials with superior strength-to-weight characteristics or other cool properties is familiar. Eye-opening proposals: Respirocytes (carry oxygen in the bloodstream so you can hold your breath for an hour), microbivores (eliminate diseases more rapidly than they body's own system), chromallocytes (removes chromosomes in a cell and replaces them with a new set). Finally, Merkle sketches out a single-stage-to-orbit vehicle made of specific (theoretical) nanomaterials that apparently has been designed by someone in a published paper, name and title I didn't catch. Bottom line: It could transport four passengers into space for a few thousand dollars.

Next: A quick intro to molecular mechanics.

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