DNA: It's Not Just for the Living Anymore
But what Nanorex accomplished during its five-year mission, Sims says, was develop an "interactive modeling tool for nanoscale design in order to generate curiosity about nanotechnology and 'bend the minds' of young students and scientists. I'm satisfied Nanorex achieved that goal to a significant degree and I'm proud of that."
He also did create a real CAD system that was used to design and fabricate a nanoscale structure. His open-source software product, Nanoengineer-1, designed DNA origami --- a process pioneered by Rothemund's CalTech lab --- from scratch. His design was the first step in fabricating a NAND gate using bottom-up self assembly. "Ultimately, we wanted to create a functional 1-bit adder using DNA and carbon nanotubes," Sims says. "It was very ambitious, but I'm convinced we could have taken this very far. At least we made the initial NAND gate tile which was a huge achievement. I'm very proud of this."
So, Nanorex is no more, but DNA nanotechnology continues to develop, as the work of Seeman and Rothemund are expanded upon by other researchers. And Nanoengineer-1, Nanorex's free open-source software, has been downloaded more than 10,000 times. The seeds are there for continued experimentation and growth.
Just this past October, Seeman developed artificial structures out of DNA strands that can self-replicate, another important step along the way to self-assembling, self-replicating nanomachines. This is no longer science fiction. The naysayers of a decade ago have already been proved wrong many, many times.
Think nanobots are just science fiction? Well, maybe, but a group of Dutch scientists recently took a single-molecule car out for a spin. The car, itself, is just what we here in Detroit like to call a prototype. They're playing around to see what they can do. Tibor Kudernac, a chemist now at the University of Twente, the Netherlands, and lead author of the paper, tells the BBC: "There are ways to play around," he said. "That's what we chemists do --- we try to design molecules for particular purposes, and I don't see any fundamental limitations."
Now, here's where I depart a little bit with true nanotech believers. As I hinted at the beginning of this column, I do not necessarily believe that the existence of life is, in itself, proof that we can build molecular machines. It is not a good argument to use. Maybe someday, in the far-distant future, we can create a toaster-size "molecular assembler" that can build whatever we want one atom at a time. But, the fact is, after you hit the "print" button, you still only have a model of the thing … and not the thing, itself.
This might be primitive of me, but I believe life is analog. Not digital. With DNA, we are not inventing a nonexistent digital reality. We are beginning with the true building blocks of life. What we create after that is up to us.
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