Update nanosystems.html

nanosystems.html

@@ -411,12 +411,23 @@ <h1 id="ch3">Chapter 3: Potential Energy Surfaces</h1>
 <h1> Volume 2: Back From The Desert </h1>
 <img src="images/vol_2_cover.jpg" alt="volume 2 cover">
 
-<h1 id="ch4">Chapter 4: Molecular Dynamics</h1>
-<h1 id="ch5">Chapter 5: Positional Uncertainty</h1> 
-<h1 id="other">What Other Techniques Besides AFMs Are Interesting?</h1> 
+<h1 id="ch4">Chapter 4: Molecular Dynamics</h1> 
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+<h1 id="ch5">Chapter 5: Positional Uncertainty</h1>  
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+<h1 id="other">What Other Techniques Besides AFMs Are Interesting?</h1>  
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+<p><b>Hydrogen Depassivation Lithography (HDL):</b> Zyvex has been doing this and while it’s gotten better I don’t see it as a real competitive thing. It’s still interesting though since it has experimental results, but I wouldn’t bet money on it. </p>
+<p><b>MEMs:</b> I don’t think that this is the move. Yes, Feynman had the idea of the machines make the machines that make the tiny machines which modeled how the industrial revolution worked because the machines made the tiny machines made the tiny machine, but yeah it feels like a mediocre strategy. MEMs also tend not to work from the principles of nanomachines (which molecular biology does, kind of), so I don’t think that they’re a good analogy to reason from. They’re a local optima, we can do better. </p> 
+<p><b>Optical Tweezers:</b> My verdict is that this is a great technology for scaling quibits but not for anything else. Despite the <a href=”https://arxiv.org/abs/2212.01037”>throwing atoms paper in 2022</a> and the <a href=”https://www.quantamagazine.org/the-best-qubits-for-quantum-computing-might-just-be-atoms-20240325/”>2024 Caltech 6100 atoms</a> paper and the cool science (literally, although it’s ultracold) of optical tweezer arrays (which are kind of like egg cartons of light that atoms can slide into) which you can read about <a href=”https://www.nature.com/articles/s41567-021-01357-2”> here</a>, I don’t see it as a good technology for APM. It doesn’t have the massive industrial scaling of beam methods and isn’t as precise for manipulating atoms as AFMs are, and nanophotonics/plasmonics are, well, very much open scientific questions. This technology is fascinating though and should be pursued further, just not necessarily for the purposes of APM. </p> 
 
+<p><b>Synthetic biology/Protein Blocks/DNA Nanotechnology/Spiroligomers:</b> First, I acknowledge that this is “lumping together” many things and that some folks are justifiably going to be mad at me for this. I would secondly like to note that I hope all research in these areas continues, as they are fascinating and will likely have much benefit for humanity, especially since biologists and other scientists (such as physicists) need to talk a lot more to each other. However, I don’t feel as though these technologies are a meaningful step towards high throughput atomically precise manufacturing, they feel more like a local optima that sounds smart but isn’t the correct pathway. I hope someone can convince me otherwise, but if one was not using nc-AFMs, I would instead recommend the following: </p>
+<p><b>Scanning Transmission Electron Microscopy/Electron Beam Lithography (STEM/EBL):</b> This is work that’s been done a lot by Sergei Kalinin and his group at ORNL. I think that this combined with some kind of ALD (Atomic Layer Deposition) or MBE (Molecular Beam Epitaxy) could be interesting since my mental model of these technologies combined would be the ALD/MBE as a deposition (like a 3D printer) while the Electron beams act as etching or removal technologies, similar to a CNC. I’m currently reaching out to Sergei in order to better understand this technology, but there are a variety of open source SEM (Scanning Electron Microscopy) efforts and after our initial STM and nc-AFM experiments I would like to explore this in parallel for basic science efforts, since you can parallelize and speed up these beams through greater engineering and lowering the “idiot index” of parts used in these devices. </p>
+<p><b>There’s also HAL (hydrogen abstraction lithography) and PALE (patterned atomic layer epitaxy), but I haven’t read into those very much.</b> </p>
 
 <h1 id="addideas">Additional Ideas I've Discussed</h1>  
+<p><b>Meet in the middle manufacturing:</b> This idea has been brought up by J Storrs Hall, Stripe Press, Anna-Sofia, Jacob Swett, and others. <a href=”https://www.contrary.com/foundations-and-frontiers/molecular-manufacturing”>(Link to Anna-Sofia’s Article, which is the best source for this concept in my opinion.)</a> The rough idea is that one could pursue bottom up (Drexler and/or Synthetic Biology) and top down (traditional lithography, MEMs, E-beams, etc.)  methods to then “meet in the middle” as a way of achieving atomically precise manufacturing faster than just going after one approach solely. I believe that this is a very interesting idea, specifically E-beams and Drexler (nc-AFMs) combined for reasons I will spell out more in the future, but it doesn’t seem to be getting as much attention. Personally, I love ideas that focus on how we can be practical and get to APM as soon as physically possible. </p> 
+<p><b>Convergent Assembly:</b> Essentially, this was a conversation over Twitter/X that I had with Mark Friedenbach on 4/4/2024. I stated that I didn’t understand convergent assembly and the “middle” parts of molecular nanotechnology (namely, that molecular motors seem possible and that the math of “given this technology, here’s what it could do, such as the first chapter of nanosystems” seems to work, but the plan to go from Step 1 to Step 3 is very vague. Lukas Suss pointed out that Nanosystems intentionally had little content on bootstrapping and that “Sadly it is still the one and only technical book written on these kinds of diamondoid systems. A new book on new insights in friction mechanisms would be interesting. With focus on reproducible numbers.”). Mark then explained convergent assembly as such <a href=”https://twitter.com/MarkFriedenbach/status/1776085519505526842”   >here:</a> “Can you at least explain your understanding of what convergent assembly is? I suspect we are talking about very different things and that this is merely a definitional misunderstanding.For my side, convergent assembly is the natural extrapolation of the mechanical motion frequency scaling law: reducing linear dimensions by a factor to 1/10th increases frequency of operations by 10x.Small scale systems produce many parts quickly, and large scale systems assemble few parts slowly. So it becomes natural for larger scale systems to source parts from multiple smaller-scale systems, with each layer going up the chain operating at lower speed (but higher mass).The net result is constant mass throughput in the manufacturing system, allowing high-yield atomically precise manufacturing of macro-scale quantities of product.” Mark Also mentioned “Have you seen the concept of microblocks? That seems most likely to occupy the intermediate scale. Macro-scale products made of micron-scale parts with tiling geometry.” from the book Radical Abundance (2013), from Drexler. </p> 
 
 
 <h1 id="emails">Responses To Emails That Don't Fit Anywhere Else</h1>