Nanotechnology

Posted by on September 4, 2006; This entry is filed under Uncategorized.
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Productive Nanosystems

First molecular biology and now nanotechnology.

4 Comments

  1. Dobeln September 4th, 2006 at 1:09 pm

    Seems you got Cornered! :) (On NRO)

  2. bbartlog September 4th, 2006 at 5:50 pm

    More info? I see a video which may or may not be backed by serious theoretical work on whether the described setup will work – is there a paper that goes with the video or something? Also as usual not too much detail on how we get there from here :-)

  3. Fly September 4th, 2006 at 7:19 pm

    The animation is a product of the Foresight Institute, http://www.foresight.org/ 
     
    The site has a publications page with white papers. 
     
    In my opinion, nano-assemblers are still two to three decades away. First, people will harness molecular biology. University labs are already taking the first steps to create a microbiology-based engineering capability. Second, people will combine microbiology and nanotechnology. This is already being done as protein and RNA probes are combined with nano-capsules. Eventually, there may be nano-factories as depicted in the animation. 
     
    The Foresight Institute is focusing on a bottom-up approach, in which molecular machines are designed and assembled molecule by molecule. There has been progress in building modest molecular machines. 
     
    Other groups are focusing on chemical self-assembly, e.g., using DNA to form a regular lattice on which to deposit non-biologic functional units to make circuits. 
     
    Finally, there is the traditional top-down approach followed by the electronic industry, in which each product generation has smaller dimensions. 
     
    I think all the approaches will turn out to be useful.

  4. Orion September 5th, 2006 at 10:38 pm

    Cool videos, Fly! Thanks! I think self-assembly is the most interesting problem facing 21st-century science. 
     
    As a graduate student I remotely assisted the U. Illinois folks that study the function of real proteins like Aquaporin using molecular dynamics simulation tools like NAMD. 
     
    I was suprised to see how much real molecules wiggle around–back in Chem 101 I thought of bond angles as fixed, but molecules at room temperature are amazingly loose, compliant structures. Hydrogen atoms on an organic molecule vibrate at femtosecond timescales. In just a picosecond, a small molecule like water will explore dozens of nearby locations. This wiggliness is the real reason biology even works–every protein in a cell gets a chance to react with its neighbors trillions of times per second. 
     
    It looks to me like the Foresight nanotech is conceived as operating at near absolute zero, because the molecules aren’t moving, and it’d be tricky to get covalent reaction (angstrom-level) machine-style tolerances at normal temperatures. Running a system at absolute zero does eliminate a huge number of possible failure modes, but it seems darn tricky to really achieve–how do you quickly suck out waste heat? And worse, this whole “pre-planned molecule paths” approach seems to be throwing away one of the most powerful tools for nanofabrication–you don’t have to explicitly line up and stick molecules together, because in a warm solution they’ll just find each other and react on their own. 
     
    The bottom line is that nature has been working on self-assembling molecular-scale machines for four billion years, and nature’s damn good at it! I think we’ve got a lot more to learn from biology before we can begin to move beyond it into The Diamond Age. Lesson 0 is that the organization of a cell, organization, or ecosystem is a lot more like a free-market economy than a factory…

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