Research on Molecular Mechanosynthesis is Progressing Slowly

Physical experiments into molecular mechanosynthesis have been rare, so what results do we have thus far?

3 min read

I have admired Philip Moriarty since I first saw a video of a nanotechnology debate at Nottingham University taped in 2005 in which Moriarty stood up and asked some pretty pointed questions to some of the panel members who were proposing molecular nanotechnology (MNT). (The nearly two-hour video I have included below).

The tenor of Moriarty’s questions and comments are exemplified by this comment: “To date there has not been a single mechanosynthesis experiment, in that the most basic step in terms of abstracting a hydrogen atom from a diamond surface has not been done. That has to be proved in order to demonstrate the viability of the machine approach. I’ve never been able to square that with the statement that there are no showstoppers—not one experiment has been done, correct?

I’m not sure he received an answer to that question. It’s likely he was told that Freitas and Merkle had run some computer model simulations. 

But my respect for Moriarty grew when he decided that since no one felt compelled to do these experiments, he would. And he didn’t moan about how he couldn’t get funding, he made a proposal for an experiment and got it funded. Then he set about beginning the long and arduous job of setting up experiments that weren’t done solely in the forgiving world of a computer model.

So I was intrigued to see what the update was on his research and we get it an interview with Sander Olson at the blog The Next Big Future.

The upshot is that things are not progressing well with diamonds but his work with silicon is a bit more hopeful.

So we soon get the question: Are you still a skeptic? (Just a personal note on the word skeptic, it is my sincerest hope that every scientist is an unashamed skeptic. But it seems in this context the word is presented as some kind of pejorative.) Thankfully, Moriarty without hesitations acknowledges that he indeed is a skeptic.

“I believe that the concept of molecular manufacturing - of creating macroscopic objects atom by atom for any material, is flawed,” Moriarty says in the interview. “I do not believe that this technique can be scaled-up to manufacture macrosized objects for arbitrary materials.”

Moriarty takes great pains to distinguish the recent body of thought on the subject from the original proposals of Drexler.

“In “Nanosystems” Drexler makes a careful and clever choice of the type of system required for mechanosynthesis/molecular manufacturing, taking into account the key surface science issues,” Moriatry argues. “I’ve never been able to see why it is then claimed that these schemes are extendable to all other materials (or practically all elements in the periodic table), for the reasons I discussed at considerable length in my debate with Chris Phoenix.”

Moriarty even weighs in on the Smalley/Drexler polemic that occurred on the pages of Chemical & Engineering News back in 2003.  “Richard Smalley, despite raising other important criticisms of the molecular manufacturing concept, misunderstood key aspects of mechanosynthesis and put forward flawed objections to the physical chemistry underlying Drexler’s proposals.”

A good portion of the remaining part of the interview revolves around Moriarty’s work and views on AFM and SPM research and makes the entire interview worthy for a thorough read. 

But back on the MNT front it would seem that the prospect put forward by Ray Kurzweil and others that “Around 2030, we should be able to flood our brains with nanobots…” seems more than a bit optimistic if Moriarty is hoping that by 2040 “that we are at the point where we could simply instruct a computer to build nanostructures, and let the computer handle all the details – no human operator involvement required.”

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3D-Stacked CMOS Takes Moore’s Law to New Heights

When transistors can’t get any smaller, the only direction is up

10 min read
An image of stacked squares with yellow flat bars through them.
Emily Cooper
Green

Perhaps the most far-reaching technological achievement over the last 50 years has been the steady march toward ever smaller transistors, fitting them more tightly together, and reducing their power consumption. And yet, ever since the two of us started our careers at Intel more than 20 years ago, we’ve been hearing the alarms that the descent into the infinitesimal was about to end. Yet year after year, brilliant new innovations continue to propel the semiconductor industry further.

Along this journey, we engineers had to change the transistor’s architecture as we continued to scale down area and power consumption while boosting performance. The “planar” transistor designs that took us through the last half of the 20th century gave way to 3D fin-shaped devices by the first half of the 2010s. Now, these too have an end date in sight, with a new gate-all-around (GAA) structure rolling into production soon. But we have to look even further ahead because our ability to scale down even this new transistor architecture, which we call RibbonFET, has its limits.

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