Beiträge von lsuess

    I just realized that since the last time I've checked there was a lot of movement in the DIY SPM space.
    Specifically beside DIY STMs there's also stuff about DIY AFMs online now.


    The first two nearest things (near in therms of google search metric) that sprang into my face where:
    1) https://openafm.com/
    2) http://www.stromlinet-nano.com/ (~$3000 closed source)
    There's an image of DNA origami made with this microscope: (JUMP TO 0:28)


    At least for DIY AFMs the imaging of DNA structures seems to be on the very limit.
    Maybe this would work a lot better with DIY STMs.
    I think so because AFAIK it is way harder to get down to atomic resolution with AFMs than with STMs due to:
    * the lack of the exponential current decay benefit
    * the tips being fabricated from some material like silicon nitride with more rounded tips then the metallic etched wire tips (true?/false?)


    So contrary to what I thought there's no electrical pre-amplication on the icspicorp chip yet.
    Doing the ultra low noise amplification is a critical more expensive part of the system that I thought could be mostly avoided now.
    So on the current chips there is only stuff for excitation of vibrations for AFM tapping mode ??
    Does that mean for usage in STM mode the current chips are no better than a cut piece of wire?


    "Please feel free to tell us about the application you have in mind ..."
    Hmmmm .... A cheap stage targeting the DIY-geek-tinkerer / hobby-science / citizen-science market?


    Given the not exorbitant or at least not plainly obvious amount of application cases: Would there be sufficient demand?
    Selling it just as "toy" where the usefulness factor is not as important would not require a 10x price drop but rather a 100x price drop - so that's not viable. ...
    Personally I'd like to know about the feasibility of imaging (and manipulation) of DNA structures (no full atomic resolution needed) with cheap solutions.


    Sidenotes:
    * AFAIK a lot of the the (professional) really cool atomic resolution and manipulation stuff was done with high stiffness tuning forks -- non contact tapping-STM I think.
    * "scanning microwave microscopy" -- first time I hear about that -- I guess I need to extend my knowledge in that direction.


    PS: If you really wanna try something and need something 3D modeled for 3D printing I can help there.
    I did quite a lot of fully parametric 3D modelling in OpenSCAD in the past as you can see here:
    https://www.thingiverse.com/mechadense/designs

    Yes icspicorp.com is what I was referring to.
    Sorry, I forgot to add that link.


    So the price for the frame-component really is oriented on demand and likely far above potential (minimal) production cost.
    They probably reason that dropping the price (too sudden) won't raise the selling numbers enough to compensate.
    Just as it was with home 3D-printers a few years ago but this time their judgement might be more accurate.


    Even though the integrated SPM chip may have been more expensive in development than the frame-component it seems they want to amortize their development costs mostly with the frame-component. (except the chips - contrary to advertised - break regularly - which I don't really believe)


    I see kind of a dilemma here though:
    Assuming our reasoning that a much cheaper frame-component is possible is correct and someone pretty soon actually makes a ten times cheaper replacement
    with minimal development costs (even in small batches! e.g. kickstarter - legality questions ... ) then icspicorp's small volume frame sells might drop to a point where might not amortize their development costs anymore. And without demand climbing proportional to the dropped price a price battle won't be an option.
    If this goes so far that icspicorp stops selling their cheap integrated SPM chips then the price under-cutter has basically killed its own nourishing ground.


    Is a little less exaggerated scenario (just drops in business not full failure) too far fetched?
    Do they have thought about such a scenario?
    Is there some defense in place (being it intentional or unintentional) ? Proprietary software?
    Or - as I realize while writing all this:
    Is it possible they assume and want early price undercutters to take the risk of testing the market readiness from them?


    The outcome will most likely end up somewhere between the pessimistic and optimistic extreme.
    But I guess I'm just over-analyzing this.

    1) Stiffness is a key for advanced positional nano-fabrication.
    2) For some fixed material stiffness falls with shrinking size.
    So this Foam might prove quite useful for structural components in future nanofactories (and other advanced nanosystems).


    The found foam is basically a superimposed union of
    1) trivial cubic foam and
    2) trivial octet foam (out of octahedrons and tetrahedrons)
    nothing fancy - easy to model


    Paper: "Mechanical metamaterials at the theoretical limit of isotropic elastic stiffness"
    http://www.nature.com/nature/j…ent/full/nature21075.html
    UCSB shortnews: https://materials.ucsb.edu/new…s-first-perform-predicted
    UCSB news full article (linked): http://www.news.ucsb.edu/2017/017705/great-shape


    UCSB news article with video (not linked): http://www.news.ucsb.edu/2015/015304/geometry-strength
    Author: "... This material is found to archive theoretical bounds for isotropic stiffness. ..."
    He's referring to something called the "Hashin-Shtrikman Bounds" of which probably few people know about.
    http://subsurfwiki.org/wiki/Hashin%E2%80%93Shtrikman_bounds

    At the 2014 forsight institute conference Neil Sarkar held a talk called "microscopic microscopes for the masses"
    https://www.foresight.org/conf…croscopes-for-the-masses/
    (There was a video online but I can't find it anymore. Was it removed?)
    Today I got an e-mail notifying me that they finally sell their microscopes.


    With a price point near $10k I doubt this will make it to the masses anytime soon though.
    I think that's about one order of magnitude to high.
    As I understand the point of the project was/is to pack/cram most of the functionality into/onto chip.
    With $250 I think the tips are bearable priced.
    I'm wondering though why the frame and rough positioning turned out to be so darn expensive.
    Maybe this cries for a DIY 3D-printable replication.
    AFAIK there are some people (on thngiverse) successfully doing high accuracy optical system mirror adjustments with just crude 3D printed parts.
    For drift reduction maybe adding temperature control (via a Peltier element) is needed but I don't see that pushing the price to near $10k
    So what makes the price?
    Software ?! Machining ?! The linear bearings ??
    Long range rough positioning vibration Piezo drives ?
    Maybe secondary amplifier electronics ?

    INCA is based on the tensegrity geodesic structures of Buckminster Fuller, and the fullerene molecule.

    Geodesic domes without internal structure fall (to my understanding) not under the category of tensegrity.
    It just so happened that Buckminster Fuller who is known for geodesic domes also invented the term tensegrity.


    I suspect heavy usage of pure breed tensegrity in advances APM products such as lighter than air structures.
    Aerial Meshes
    I don't think tensegrity will be all that important in the early bootstrapping phase.
    With semi stiff foldamers and bulky nodes (bulky => non mathematically ideal) it's hard to draw a line what is tensegrity and what not.


    There are two things to discern here:
    A. Space Trusses (nodes take neither tourques nor bending moments only tension and compression)
    B. Space Frames (nodes take torques and bending moments too)


    Tensegrity is a subset of A with pure tension elements (ropes chains) allowed.
    The main advantage of tensegrity is that it auto-equilibrates internal and external loads
    thus you get maximal stability for minimal design complexity and maximum part reusability
    (for the cost of lower reliability - single point failure => full collapse).


    For nanofactory bootstrapping first and foremost stiffness needs to be maximized.
    By adding more and more redundant structures you move more and more to B (space frames) which is as far away from tensegrity as it gets.


    Just recently a record was set on the biggest stiff empty de-novo protein cage constructed by bottom up self assembly:
    See: http://www.foresight.org/nanodot/?p=7154
    This is a dodecahedron.
    A dodecahedarl protein frame wouldn't be stiff if it would fall into the class A of space trusses.
    (Deltoids like the octahedron have that interesting property)
    It's stiffness depends on the fact that the bulkiness of the nodes can take torsion and bending moments.
    So this de-novo protein dodecahedron is a spaceframe and most certainly not a tensegrity structure.



    One of the big plusses with the INCA system as the bootstrap for MNT is this: It is based on the curvature we see in the biological and natural world. Look at the spirals and curved structures in nature, such as in DNA helixes and protein chains and more.


    I think this is just about aesthetics.
    Smart design usually leads to aesthetic products.
    But the other way around finding smart products starting from aesthetics can be much more difficult.
    It helps when your design space is small.
    This is not the case when you start from a point as general as spirals and curves - too vague.
    An (only periphereal APM related) example I know of is Conal Elliotts research about automatic differentiation (with heavy usage of statically typed programming as unconditionally required basis) where he ends up with infinite multidimensionall derivation towers (taylor series) basically for free just by pursuing aesthetics in code.


    This is relevant for APM since it is immensely useful for 3D modelling (surfaces normals curvatures).



    Lastly about that "invention":


    I'm surprised that his invention passed the threshold of originality.
    As I see it it' this is just a ball with three springs on it.


    I do not have the time to read through the details of that patent.
    Patents aren't necessarily made for quick comprehensibility.


    Sadly consulting the the referred to website for more information
    (http://www.incanautchallenge.com/) is no longer possible since it's gone - victim of internet amnesy.
    It seems that domain name got annected by some japanese wordpress blogger.


    Beside the patent I found no openly accessible information other than that facebook page behind the usual sign in wall: https://de-de.facebook.com/INCAnautChallenge/


    Steve Bridgers presentation does not come over very convincing - at least for me.
    He doesn't show a closeup of his invention.
    Ok a bit better:


    Also he conveys the feeling of "I am so cool and so much better than you".
    Then the other videos of the same YT channel are a little ... obscure.
    I liked this entertaining excerpt:
    "... Because it moves mechanically and dynamically we can MOVE IT ..."
    ROFLmao


    Aside from that this "challenge" is likely long gone (if it ever happened).
    The video was published five years ago in Sept 2011.


    You can see some of the basic designs and diamondoid-inspired structures made with this.

    Self similar stuff is interesting.
    My avatar image is a tripod made of sp3-carbon atoms (which themselves have tripod-symmetry) - pretty fundamental. I'm not yet sure where this specific design could be of use.

    What do you all think? Protein folding? DNA nanomachines? SPMs with molecular grippers like Drexler and Merkle and others mentioned years ago? Engineered bacteria and viruses? Laser, Electron Beam and other energetic beam systems?

    I guess a bit of all of them - viruses and bacteria only as means for producing artificially designed de-novo proteins.


    We had some related discussion about possible approaches here:
    What are the remaining lurkers up to?


    The next major milestones I'm looking for are:
    #) Putting
    hierarchically self assembled (already experimentally demonstrated in isolation)
    hinged and rigid (already experimentally demonstrated in isolation)
    DNA/Protein/Peptoid/Foldamer structures onto photographically etched chips (already experimentally demonstrated in isolation)
    such that they get aligned to the etched structures.
    #) Introducing high rate bistable electrostatic actuation via this chips surface.


    Then It gets more murky:
    #) Introducing mechanical demultiplexing in the self assembled sufficiently stiff foldamer structures.
    #) Making kind of like a protein block based 3D printer (on chip surface) and thereby get rid of unreliable high error rate self assembly.
    #) Switching to bio-minearlisation materials (I perceive a big knowledge gap here) - As elaborated in "Radical Abundance" Appendix
    #) Building micro vacuum chambers and finally switching to advanced materials like diamond and silicon. - Also as elaborated in "Radical Abundance" Appendix


    In one of his more recent presentation Eric Drexler presented an approach for in liquid free floating foldamer activation mechanosynthesis devices.
    He proposed to design
    #) a three axis site activator via hierarchical self assembly and
    #) use trichromatic light for directed motion actuation (already experimentally demonstrated in isolation).

    I guess you assume a level of molecular nanotechnology, and mechanosynthesis where you can place every element of the periodic table in any practical way physical law permits and pick atoms from any local molecular environment.


    Long before that level of capability will be reached earlier forms of high throughput advanced molecular nanotechnology, and mechanosynthesis
    (e.g. synthesis of diamond and graphene) will be available. Those forms of mechanosynthesis are likely to be rather limited in the way they can place/handle atoms. (Side-note: That limitedness does not transfer to the earlier products - completely different behaving mechanical metamaterials can all use the same base material.)


    Of course on the nanoscale atom and molecule bonding topology is always fundamentally reversible. But that does not mean that implementing the backward process technically is as easy as implementing the forward process. Actually there a number of reasons why implementing the backward process (disassembly) is much harder than the forward process (assembly).


    Since mechanosynthesis is basically a blind open loop control assembly process (heavily relying on extremely low error rates) once some in the past mechanosynthesized crystal-molecule assemblies have incurred radiation or thermal damage, mechanosynthetic disassembly can't be performed by simply running a nanofactory in reverse - this would just end in a mess. Even if the product crystal-molecules are damage free it's still difficult. Some assembly steps may have way higher error rates in reverse (that's where energetic reversibility comes into play).


    So I'm concerned about giant mountains of diamondoid waste piling up not because recycling is fundamentally impossible (which is certainly wrong)
    but because I see a timespan coming in which it is technically WAY easier (and economically cheaper) to just create systems for making diamondoid crystal-molecules by mechanosynthesis instead of creating mechanosynthesis systems that are also capable of taking diamondoid crystal-molecules apart.


    (Re-usage of microcomponents may mend that problem but only to a degree since they may become obsolete - analog to software.)

    One issue I have with predictions about AI is one that Eric mentions too briefly in his talk: goals and motivations of AI. All living things have a goal built into them due to the way life evolved: perpetuate oneself and one's offspring. Eric states we wont know or will be unsure of the goals AI will have. I don't see why we wouldn't, since unless we explicitly program goals in, the AI will have intelligence but it wont have any motivation to do anything with it. Without goals it wont have motivation to act for or against anything. Probably a good reason not to program in any goals.

    <sarkasm> All living things except humans in wealthy countries too smart for their own good. They die out. </sarkasm>


    Reinforcement learning means rewards must be defined. Thus neuronal AI without goals doesn't exist.
    We make AI to serve a purpose (even if its just nonsense "art") thus we train it with the data-sets we have readily available and tell it how good it does at reaching its goals. This already is leading to unpleasant discriminatory occurrences due to politically or racially or gender or ... biased training data.


    A major problem is that if an AI finds a way to cheat for getting its reward and its unsupervised it will start and continue to do so perpetually - potentially causing serious trouble. With multiple agents supervising themselves mutually there can be a self regulating system but by our limited intelligence we will barely have the means to know whether and where potential system instabilities lie and how severe they might be.


    Most scary I find the kind of personal assistant AGI's that google is currently very actively building. This is basically becoming a virtual version of yourself knowing yourself inside out. It - for the better or the worse - could live on after your death. If the user is/was an a*****e spammer you might get a very nasty AGI. BTW rouge AGI's are certain to collaborate if beneficial for them. A cyberspace inter AGI war may become a possibility.


    With advanced AGI sooner here than advanced nanotechnology humanity may come into the inconvenient "being a pet" situation without the option for anyone to upgrade the brains to keep up. This is all SciFi right now but if I happen to see this day I hope most of the serious flaws that current day software carries with it will become resolved before any mental upgrades begin - I don't want google/facebook/... in my head nor do I want dependency hell nor uncontrollably piling up entropy invariably leading to a system crash and necessary reinstall - which people still think its normal - IMO it isn't. <joke> Person A (panicking): "My new video driver isn't working properly I just see blue what should I do? ..." Person B (indifferent): "Just delete and reinstall the brain-ware you're running." Person A: "WHAT?!" </joke>


    What mystifies me about AI/AGI is the fundamental differences to the human brain:
    * just a few basic instincts flooding the whole brain as feelings - vs - very topically fine-grained reward structures
    * the fundamental single-threadedness of the human brain - ever tried to listen to two persons at the same time? - can this be learned?

    Someone is likely to prove me wrong, but I'm not sure that that foldamer engineering will bootstrap advanced APM. At best I suspect it may be a dispensable tool, much like one can use a screwdriver to pound a nail - though a hammer would be the better tool. On the other hand, there is no easy way to use a hammer as a screwdriver.

    The most recent developments in structural DNA nanotechnology (DNA oligomers I believe fall under the class of foldamers) made me much more optimistic about a bootstrapping pathway that relies on foldamers indispensably. Like roughly described in the appendix of Radical Abundance. (Note that with indispensable I don't mean indisposable. That is I do think that they can should and must be stripped away once bootstrapping was successful.)



    The main papers that made me more optimistic where these five:


    1) Demonstration of localized hinges and sliding rails:
    (Absoluterĺy essential for any robotics like action.)
    Papers name: "Programmable motion of DNA origami mechanisms"
    Found here: https://www.foresight.org/nanodot/?p=6430
    Full open content: http://www.pnas.org/content/112/3/713.full.pdf


    2) Hierarchical self assembly of structural DNA nanotechnology:
    (Essential for more complex systems)
    In the first step the normal method floppy DNA oligomers find and link. In the second step the finished assembled stiff cubic/hexagonal voxel grid building blocks self assemble by shape complementary (reversibly driven by varying salt concentration)
    Papers name: 'Dynamic DNA devices and assemblies formed by shape-complementary, non-basepairing 3D components'
    Found here: https://www.foresight.org/nanodot/?p=6606
    Full open content: http://science.sciencemag.org/…EI&keytype=ref&siteid=sci


    3) Bohr radius resolution manipulation with DNA nano-structures:
    (Essential for early forms of mechanosynthesis)
    Papers name: "Placing molecules with Bohr radius resolution using DNA origami"
    Found here: https://www.foresight.org/nanodot/?p=6890
    Somewhat hidden paper: http://bionano.physik.tu-muenc…/funke_NatureNano2015.pdf
    Supplementary info paper (BIG): http://bionano.physik.tu-muenc…ke_NatureNano_2015_SI.pdf


    4) Assembly of multi micron scale AP pegboards:
    (Probably useful for organizing bigger systems via AP self centering pick and place that lacks atomic resolution.)
    Papers name: "DNA brick crystals with prescribed depths"
    Found here: https://www.foresight.org/nanodot/?p=6350
    Full open content: https://yin.hms.harvard.edu/publications/2014.crystals.pdf
    Supplementary info paper (BIG): https://yin.hms.harvard.edu/pu…ns/2014.crystals.sup1.pdf


    5) Templated gold grwoth in AP DNA nanostructures:
    (Maybe useful to include stiffer parts for tooltips though this does not look too controllable - bulging)
    Found here: https://www.foresight.org/nanodot/?p=6324
    Papers name: "Casting inorganic structures with DNA molds"
    Full paper: http://www.ncbi.nlm.nih.gov/pm…60265/pdf/nihms641769.pdf



    What I'm still eagerly waiting to see is:


    A) Fast bi-stable electrostatic actuation of DNA hinge nano-structures via electric fields emanating from very small contacts on a chip surface.


    B) Demonstration of AP single moiety mechanosynthesis with water synthesizable diamondoid minerals (quartz/pyrite/apatite/calcite). This hasn't been demonstrated in with macro-scale AFMs either.


    I recently had some discussion defending the idea of advanced APM where I wrote a bit about my own interpretation of that pathway beyond of what is written in the appendix of Radical Abundance.
    You can find this all the way at the bottom down here:
    https://debunkingdenialism.com…omic-scale-manufacturing/


    Sorry about the amount of links here, but I think they're relevant.



    I think of SPMs as one tool of many that will be needed to bootstrap nanotechnology. That an STM has limitations is no different than other tools. Based on my reading of history, I think progress in nanotechnology will only take off once more "amateurs" can begin work on it.

    I believe one issue that got in the way was lack of money or capital - and uncertain demand. While a determined amateur can build a marginally working inexpensive hobby STM, buyers of commercial systems have higher expectations and getting a refined product to market is not cheap. Of course, back then we didn't have Kickstarter, GoFundMe, IndieGoGo, or RocketHub as options to raise capital and establish a seed of potential customers.

    I do too think of SPM as one tool of many that will play an important role.
    I think parallel AFM in the form of mechanosynthesis and pick and place action at the micro and nanoscale will do a big part of the work. Single tip synthesis might be useful for figuring out reactions or putting bigger blocks together but building up a diamondoid assembler with a single macro-scale AFM (the early idea now dismissed by Eric Drexler) by now seems to me like jumping to the moon with just your legs - metaphorical speaking.


    The problem I feel is that with what is archivable by DIY means and a little more professional kickstarter funded means (provided it gets funded) is not sufficient for making meaningful bootstrapping progress.


    I feel that some very essential tools will not make it to a widely available DIY state (e.g. cryo TEM tomography, UHV Systems - except something like my crazy micro UHV system idea miraculously works out, automatic pipetting systems ... to a lesser degree as I'll mention further below)


    For the reasons I elaborated above I think that systems of hierarchically self assembled foldamers will play a major role too beside SPM. Thus I'm thinking of using an top down AFM to picture and interact with bottom up foldamer structures. And those need some of these additional capabilities.


    About kickstarter funding:
    Who is really interested in playing around with an relatively cheap but not extremely toy-like cheap ~999$ SPM device beside a handful of geeks? I mean right now and not when it becomes really interesting due to APM bootstrapping beginning to succeed. (Kind of a "who would need a computer in his home" situation.)


    I doubt that major parts of bootstrapping will be done by a large DIY community. (I'm not happy about that)
    I think it's not unlikely that much of the bootstrapping will happen in service provider labs for early nanotech medical companies.
    Sadly this could quite likely result in that the products will be accompanied with a lot of closed source problems restrictions and regulations.


    I'm not saying that I'm certain that a cheap SPM kickstarter project won't work out funding wise.
    I just doubt that DIY to semi professional SPM living-room devices will play a major role in bootstrapping.


    In the macrocosm with repraps there's a lot less that can't be done DIY or is hard to do DIY.
    Also the products have immediate usability value.
    Even with these things in its favours evolution of repraps isn't crazy fast.


    To drift a bit off-topic:
    We still don't have a self replicating 3D printer that not only prints but also assembles itself.
    I think this should be possible (not a small machine) and could drive the cost fo 3D printers down further ~50% and give additional
    6DOF robotic pick and place capability (remember DIY massive automatic robotic pipetting system for DNA nanotech I mentioned before?)
    Also such a self replicating pick and place robot would demonstrate principles for self replication that uses standard prefabricated parts as building blocks. These principles then could at least in part be applied to nanosytems out of AP self assembled foldamer parts. And much later the principles could be used in the second assembly layer of advanced nanofactories - albeit with a wider less compact cycle meaning even more less generic parts.
    A self assembling macro robot is what I'm attempting with my reprec project Idea:
    http://reprap.org/wiki/RepRec
    This will soon grow, I had some major Ideas today.


    An other pathway for cost reduction beside reprap style cost reduction is miniaturization like in the computer industry.
    This pathway is big-company centric since obviously MEMS production isn't DIY doable.
    Miniaturisation of SPMs seems not to progress fast. There are some MEMS AFM approaches that still need humongous UHV systems.
    I'm not aware of any attempts of parallelizing SPMs that wield atomic resolution yet (millipede e.g. was never meant to have atomic resolution).


    Sooner or later there might come up the possibility of more or less self assembled nano AFMs ... ok I'm drifting off ...

    It would certainly be cool to make atoms visible in the livingroom but I gave up on this endeavour because:
    # I worked on a professional one (Omicron) and realized how hard it is to scan z steps greater than one or two atomic layers.
    # Playing around with structural DNA nanotechnology (and even more so for other stuff) requires a full-blown lab (automatic pipetting system ...)
    # I'm not sure whether larger DNA meshes can be scanned electrically with STM. If AFM is necessary it gets harder. DNA is strongly negatively charged due to its phosphate groups. If DNA structures sits dry on a surface I guess some alkali metal atoms (Na) remain on there cancelling the charge but I'm pretty sure they will be immobile.

    # Also there are very few surfaces suitable for in air imaging (HOPG, gold, maybe indium ...)
    I thought about the possibility of miniaturizing and demonitizing UHV systems and came up with the concept of this crazy contraption. (probably pure fantasy and a waste of time)
    https://www.youmagine.com/desi…y-miniaturised-uhv-system
    It still looks very dire when one is looking for commercially available miniaturized turbopumps.
    I'm not including designs like the one on built into the mars MSL rover which was made small by raising the price - conventional ultra-pecision machining.
    The non AP MEMS friction problem is probably the reason why there are no MEMS turbopumps yet.


    I'm wondering whether atomically precise de novo protein design could be used to create atomically tight positive dispacement UHV pumps for micron to mm scale chambers? There's probably too much low atomic weight dirt from the production process remaining and heating to>200°C would hurt most proteins. Maybe with intermediate steps - gold coating a template chamber ... drifting off again ...


    In one of the foresight conference videos there was one person presenting his companies goals to produce ultra cheap STM microscopes in masses to accelerate nanotechnology research by making the tools more widely and easily accessible - sadly I can't find that video anymore. I've also forgotten the name of the presenter. It might be "Saed"?? I'm not sure.

    Only insight I can note at this point is that false theories held up progress for decades due to the human failing of judging the merit of ideas by who espoused them rather than objective analysis of the ideas. Well, some ideas sounded quite reasonable too and evidence to the contrary was considered due to experimental error, not due to an error in the theory. It seemed to take more evidence than necessary to get a theory in trouble.

    Lipid Rafts come to mind. I heard that they may not really exist but they are everywhere in the literature.
    I don't really see how that applies to advanced APM. There I more see that correct and useful old ideas have been and are still tragically misused to judge possibilities/impossibilities in a very different context where they are not applicable anymore.

    I'm thinking of a novel design for a scanning probe microscope that I can 3D print. At least the mechanical part. STMs have already been 3D printed and the common plastics like PLA and ABS have decent properties for the purpose (such as low thermal expansion coefficient.) There is at least one piezoelectric plastic that is available (Polyvinylidene fluoride) available from at least one source (3dogg.com/c-3265319/pvdf-filament/) but expensive. Though my idea doesn't employ piezoelectrics, though more traditional approaches do.

    I thought of that too.
    Back then there was only one project around.
    It seems by now it is only accessible through internet backup services anymore :S
    http://archive.is/sxm4.uni-muenster.de
    Just for fum I made a 3D-model out of the plans they supplied.
    I wouldn't recommend to print this since it is absolutely not optimized for 3D printing - waste of plastic - ugly blocks.
    http://www.thingiverse.com/thing:42053


    One design that I especially liked is this one:
    http://www.instructables.com/i…%A1%AF%E5%BE%AE%E9%8F%A1/


    This is the one of the designs that currently rank top in the google search results:
    http://hackaday.com/2015/01/13…pe-sees-individual-atoms/
    Its so minimal that there isn't much remaining to print at all


    Here's a link to a link-list to several DIY STM projects that I found in my bookmarks:
    https://dberard.com/home-built-stm/links/


    It would certainly be cool to make atoms visible in the livingroom but I gave up on this endeavour because:
    # I worked on a professional one (Omicron) and realized how hard it is to scan z steps greater than one or two atomic layers.
    # Playing around with structural DNA nanotechnology (and even more so for other stuff) requires a full-blown lab (automatic pipetting system ...)
    # I'm not sure whether larger DNA meshes can be scanned electrically with STM. If AFM is necessary it gets harder. DNA is strongly negatively charged due to its phosphate groups. If DNA structures sits dry on a surface I guess some alkali metal atoms (Na) remain on there cancelling the charge but I'm pretty sure they will be immobile.


    Its scary how many of the links I dug through here right now are already dead.
    Luckily google image search and backup services give some chance to still find that old stuff.

    The reason I think that Eric Drexler has switched his focus is this video of a somewhat recent talk he gave:
    Eric Drexler - A Cambrian Explosion in Deep Learning
    Filmed at the Free and Safe in Cyberspace conference in Brussels in Sept 2015


    Also with Radical Abundance written and published I think a major load is of his shoulders.

    My interest in the subject is more as an area of problems that can be better attacked by nano robots than as a source for bootstrapping nanotechnology. My impression is that most of the advances in things like DNA and RNA manipulation (e.g. CRISPR/Cas9) appear to be due to discoveries of ancient enzymes that can be turned into tools than clever de novo nucleotide protein engineering.

    So you mean like the Nanomedicine books by Robert Freitas (I haven't yet read them)?
    About the discovery of ancient enzymes. Molecular biology is most definitely a treasure trove for the creation of future medical treatment methods containing stuff that we "never" could come up with ourselves. With the recent discovery of CRISPR/Cas and newer related techniques quite a "quantum leap" (in the sense of discrete not small) was made - thinking back on the low survival chances with crude methods like cloning (well this is not quite gene editing but a full swap) and the basically random point DNA insertion with older gene editing techniques. I think with more and more of the ancient stuff becoming decoded de novo nucleotide protein/peptide/peptoid/foldamer engineering (used as artificial enzyme systems A) will become more and more important. I think that in this usage case it is important to first understand "simple" examples from nature for then being able to improve upon that. There are two more possible usages for de novo foldamer engineering (foldamer being the most general case) B) as "simple" delivery vessels for drugs C) for bootstrapping advanced APM. I have a hard time to guess whether use case B is right around the corner or it will still take more than a decade to get going. What is really incredible is that the human genome is just a few gigabytes in size and still can compress so much information. If one compares that to the data size of modern operating systems it seems ridiculous. I mean the plan for how many different types of proteins and other molecules can be encoded in there ? As e metaphor the fluent passage from system design that evolved to be nicely separable and orthogonal to an completely entangled mess that contains a lot of stuff that is just there because it doesn't cause problems makes researching molecular biology like discharging an old battery - you never know how much is left. Then there's the truly random element of thermal motion not present in normal computer systems which adds another fascinating aspect. Ok I'm drifting off too far.


    ...

    >> The limits of height


    There is the interseting question about how high one can go up.


    With the capability to lift stuff high enough one could e.g. start thinking on raising the linear rail acceleration vacuum train speed to a level where it essentially becomes a propellant-less direct in orbit injection space launch systems. The space vessel is released into the atmosphere where the density is low enough such that the deceleration shock is low enough to not damage or destroy the cargo. More on that later.


    So what is the limit? This seems to be a rather hard to answer question.
    Under the assumption that with fractal truss frameworks for cell inflation buckling instabilities can be avoided scaling seems to imply that by simply keeping the mass of the internal structure of the metamaterial cells constant but spreading out the volume one can keep up with the falling density of air while also keeping up being capable of compemsating the external pressure.


    With rising volume the mass of the super thin sealing surfaces does not loose relevance. While both the mass of the displaced gas such as the mass of the outward pushing truss structure in a cell stays the same with growing volume the surface area is rising. So either it is made thinner or lifting capacity will decline. (more analysis needed)


    At some point one ends up with e.g. long trusses of single walled nanotubes (or fireproof sapphire rods) that become wobly only due to thermal vibrations alone. Or with single sheets of graphene as walls. But long before that destructive environmental factors ("forces of nature") may put a stop to ambitions.
    (Here I'd like to ask readers to please check this rough train of thought on major mistakes)


    Todays helium balloons do hit a wall at about 50km hight. They use about ~3000nm thick plastic film.
    Jaxa: http://global.jaxa.jp/article/interview/vol42/p2_e.html
    By replacing the helium fill with the most part of the shell thickness converted to internal fractal trusswork structures that resist the now occuring external pressure against the inernal vacuum one gets rid of the problem of varying internal pressure due to day night temperature variations. The other way around keeping the hight constant while the external pressure will roughly stay the same the external air density will somewhat vary with day and night - that seems less problematic.


    At a certain hight earths atmosphere begins to unmix and stratify with lighter elements higher up.
    This is called the Heterosphere. Here is a diagram:
    https://commons.wikimedia.org/…A4re_Temperatur_600km.png
    https://de.wikipedia.org/wiki/…4re_und_Heterosph%C3%A4re
    This poses an additional limit about how high one can go up.
    Its very questionable whether anything above 100km can be reached at all though.



    >> General about the Earth's atmosphere


    As a rule of thumb the air pressure in earths atmosphere halves with every 5.5km hight.
    Thus compressed down to 1bar in hypothetical weightless sapce the whole atmosphere would be about 11km thick.
    With a few exceptions it is probably impractical to put any major weight carrying stuff much above that height mark.
    Being high enough to be above the most part of the weather acticity (bottommost part of the stratosphere - like planes) may be beneficial for some applications.



    >> Propellant-less space launch system ??


    Such a thing would be a pretty dense and heavy very long perfectly circular (earth radius) tube floating at a hight where the atmospheric density is low enough that the deceleration shock on release into the atmosphere is less than 10g (How to calculate this hight for e.g. LEO speed(~8km/s) and escape speed(~11km/s)?).


    Josh Hall proposes a sequence of 80km high towers (mesopause - coldest point in the atmosphere -100°C) holding such a space launch system up. (It's rather scary imagining them crushing down). But is the pressure at 80km low enough to allow direct orbilal launch?


    A circumglobal mesosphere to thermosphere space launch corridor would even if the mass per length is kept as minimal as possible have to have a buoyancy providing enclosing lifting device of imposing diamaeter (estimated minim um at 80km: ~2km for 100kg/m; ~5km for 1000kg/m ?). This is starting to reach down into the denser parts of the atmosphere making it more like a ship swimming on the atmosphere.


    The lifting device for such a system of course would be ridiculously filigree. Its not unlikely that such ambitions will be thwarted by UV damage or micrometeorites. Wikipedia says: "The lower stratosphere receives very little UVC" but here we are higher than the ozone layer (average height of ozone layer: 15-20km tropes 20-30km - btw: stratospheric airmeshes could be used to replenish or further fortify the ozone layer) UV-B and UV-A comes through anyway. The one thing that's unproblematic is the massive availability of space precisely because nothing else is capable of staying stationary at these heights.


    As long as one does not get too far into the overpressure regime (limiting today's balloons) one may be able to extend the height limit a bit by more conventionally using a bit of lifting gasses to help. There's plenty of hydrogen available but in an oxygen rich atmosphere even when enclosed in a fireproof metamaterial this seems unsafe (true?). Both Helium and Neon are rather rather rare. It would take much time and energy to concentrate them up for lifting bigger stuff like a space launch system.
    In a hyper long term perspective one could say that concentrating up all the light noble gasses of our atmosphere is good idea since it keeps them from further depletion to outer space. About light noble gasses as a space resource could be speculated but the solar systems major helium depos Uranus and Neptune seem to have too deep gravity wells to send out anything but photons.
    Placing a vacuum balloon space launch system on Uranus or Neptune would be even more challenging due to their lightweight hydrogen atmosphere.


    As mentioned before to lift a dense and heavy objects to great heights a continuous gradient to lower density material is necessary.
    thermospheric Space launch systems would take that to the extreme.



    >> Conclusion


    As you see the amount of possibilities with this kind of technology would be enormous.


    I have an intersecting set of ideas collected on my wiki:
    http://apm.bplaced.net/w/index…ust_metamaterial_balloons


    Any feedback on those ideas?


    FIN

    >> The awesome part - for nice illustrations and dreaming about the future


    In some of the vertical "sky-strings" elevators could be integrated.
    A (pressurised) stairway to the stratosphere would be an epic multi day climb.
    Imagine the view from up there. With three point rope suspension one actually can reach any point in the sky.
    Beside the view you'll get perfect silence (and quite a bit of radiation).


    Climbing metamaterial "sky-strings" directly (assuming structure to grip on is made present) might feel like
    like standing on a a rubber air-castle. Given too much pressure the material might temporarily collapse where you stand on / where you grip it. This quickly gets more serious with rising altitude where the metamaterial becomes less and less dense (cell size grows).


    So to properly support human climbers (or other stuff like strenghtening ropes or chemomechanical power cables) proper solid structures are necessary. Albeit future devices will be very light for todays solid steel world standards these functional core structures are still heavy and dense in relation to the lifting metamaterial. So to lift the strong dense "core-structures" one has to link them to the lighter than air metamaterial. At low altitudes this might work out pretty directly (just as with current day balloons). At higher altitudes a gradient of cell size or even a fractal root net of smaller sized nonfloatong cells can softly connect to the big cells that provide negative lifting density.



    >> Transportation


    In a much smaller scale than for weather control air-meshes seem to be applicable for local urban aerial transport.


    On regards to transport I extended on the ideas presented in Josh Halls book Nanofuture:
    For reference in Nanofuture Josh Hall proposed the individualist solution without lihghter than air structures: Unthethered free moving shape shifting vessels that lift of with very very long telescoping stilts to keep downwind noise from air turbulences low. Once in the air they switch to a second sailship like mode to gain both speed and hight and once at speed they change again to a third jet like mode. He proposes "infinitesimalbearing parallel motionion cloaking". My two cents: "Adiabatic normal motion cloaking" could also be used. (I've explained both techniques above.)


    I thought about replacing the scary telescoping stilt start with safer mobile lifting pillar balloons (pillar shaped to keep space on the ground) or just static cables hangig down from the air-mesh both things would be lifting gondolas up and down to and from a rail system in the airmesh thus replacing part of the local transport with very direct congestion free gondola like transport. A form of transport that is not using the inefficient method of blowing out air for lift :S (and propulsion) but simply reaction force on the airmesh grid.


    With increasing distance it makes sense to remove the "obstacle air" altogehther.
    Airmeshes allow to put horizontal vacuum pipe "railtracks" in the air where there are no hard obstacles that make speed limiting curces necessary. Superfast "airial vacuum trains" so to say. The vacume tube could be seen as a very large unsupported vacuum-cell in the core of a very fat also vacuum filled multi celled airmesh-filament structure. For longer ranges such systems are probably best situated at the lower edge of the stratosphere 10-20km to avoid weather.


    The heavy passenger capsule drive system would be integrated in lighter than air metamaterial sausages of qite impressive diamater.
    shorter range tracks lower in the atmosphere will need a combination of tight tiedown to the ground and dynamic windload compensation sufficient for their operation speed. Longer range faster tracks can be placed in the calmer stratosphere enclosed in even more impressively sized metamaterial sausages.


    Note that in contrast to current day concepts like the hyperloop with the availability of infinitesimal bearings magnetic levitation (needing special chemical elements for the magnets) can be avoided. With the distance to the wall provided by physical contact via the infinitesimal bearings there is no rest-gas needed for air-hockey like suspension. A full vacuum is possible.



    >> Interplay with existing and future air traffic:


    Legacy air-traffic (old-timer historical kerosene driven noisemakers) should still be able to fly by sight.
    Airmeshes designers must consider that in their plans too. This may come in conflict with the desire to keep the looks of the landscape pristine for human eyes (optical cloaking).
    It is difficult to guess how much "air filaments" will be visible when designers just does not care about the looks.
    Likely appearances may be: transparent, milky, iridescent - like deep sea creatures ??


    There could be constantly open flight corridors in the mesh or the mesh could dynamical open op windsails so that vessels can move through. The sails should be able to detect punctual non wind like force and rupture in a controled reversible fashion when a plane or a bird crashes into them.



    >> anchoring density an anchoring pattern


    There are a lot of questions:
    * What would be the most practical end aesthetical mehing pattern (foam edges?)
    * What would be a good density of anchoring points on the ground in cities and on land?
    * How would one do the anchoring of an airmesh on sea?
    * What do one end up if the mesh cocept is applied to other "XYZ-spheres" (Hydrosphere, Lithosphere, Biosphere, ...)?


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    >> Intro:


    While cycling through the cornfields I recenly had an eureka moment 8o when coming up with a really wild and crazy idea about what could be possible with underpressure based robust lighter than air metamaterial structures.


    I regularly ponder about how AP technology could be applied to solve a number of problems.
    The idea I had may solve at least three of them and opens up a whole bunch of other opportunities and interesting questions.


    The three problems solved are:


    A) The problem of keeping something stationary relative to the ground in a high up laminar large scale wind-current (e.g. CO2 collectors in the sky). This seemed to be impossible without expending energy to actively move against the current.


    B) I thought about what is likely to replace today's mostly three bladed windmills that barely scratch/tap the lowest percent of the troposphere (100m of 10km). Obviously some silent sail like air accelerator/decelerator sheets/cloth/sails should become possible.
    Future "power-windsails" may be quite a bit bigger than today's windmills but they still need to be linked to the ground for counter-force and counter-torque. To avoid excessively large bases advanced sail like wind generators probably would not be made excessively large (that is a large fraction of the 10km troposphere). Also giant towers permanently emanate the danger of them coming crushing down.


    C) I thought about extracting the potential energy from rain-droplets: Clouldn't one look at clouds as almost everywhere available catchment lakes in the sky?



    >> So here's the idea:


    Specifically what came to me was to massively employ lighter than air structures in form of aerogel like "strings/filaments" (quite thick in diameter) that are tied/anchored/thethered to the ground and also intermeshed with themselves up in the sky. In the following I will refer to those structures as aerial meshes or airmeshes or airgrids. Keeping everything held at all times. This is kind of remotely similar to the principle of machine phase in the nanocosm and it too comes with a some advantages.


    These structures seem to be easy to errect in giant scales. They could be applied for:
    * aerial traffic
    * large scale energy extraction
    * and even reversely as means for super large scale strong weather control (ozone too)


    Beside spanning "windsails" in the mesh loops of the "air grid" obviously "solar sails" are also possible.
    Also there may be rains sails whick I'll explain later.
    All sails could/should be equipped with temporary deployment capability and modes that let through part of the wind (lamellas?).



    >> Wind-loads


    Obviously one must worry about excessive windloads.


    Even uncompensated advanced materials might be able to withstand windloads (estimations needed) the floating air strings / air filaments could be armed with a dense rope in the core. Assuming a density of 4kg/dm^3 a strong rope of about 1cm diamater needs to be embedded in an lighter than air string of at least about half a meter so that it starts floating.


    To prevent getting critical loads and temporary collapse of the metamaterial due to windpressure making it temporarily non-buoyant there is the possibility of windload compensation.
    Luckily with APM there's no additional cost making the whole surface an active "living" structures.
    By integrating two other technologies windoads may be reducable to acceptible levels or even completely compoensatable.
    Conveniently when there is windload there is also local power for the protection mechanisms.
    Two main technologies usable for wind-load compensation are: (names freely invented)


    A) "infinitesimalbearing parallel motionion cloaking"
    B) "adiabatic normal motion cloaking"


    A) "infinitesimalbearing parallel motionion cloaking" (this was presented by Josh Halls in his book "Nanofuture" as a means for propulsion) When air moves parallel to a surface the surface is moved with the same speed in the same direction. This replaces friction in air with much lower friction of "infinitesimal bearings" that are integrated in the air-vessels (or here air mesh strings) topmost surface layers.


    B) "adiabatic normal motion cloaking"
    When the aforementioned technique is used the air still needs to get out of the way sidewards of an obstacle.
    While the aformentioned technology/technique can compensate for parallel air motion there still remains a motion component that is head on to the surface. Obviously this must be a motion of one period/impulse of incoming and then outgoing air in the frame of reference that is moving with the parallel motion compensation speed (I hope that formulation is sufficiently comprehensible).
    What one would try here is to "grab" pockets of air compressing them down as they approach (this heats them up so they must be kept sufficiently thermally isolated to not loose their enegry) and then expanding them up again. This technique may be capable of reducing bow waves. (Though I'm rather wary about whether this could/would work or not.)



    >> Robustness against lightning (and ice loads)


    Obviously one must worry about lightning. There seem to be two polar opposite options.


    A) Adding lightning protectors of highly conductive material. On a large scale this would probably be a bad Idea. They are likely to negatively influnece weather by quenching thunderstorms and air to ground potential in general.


    B) Making the "air-strings" electrically highly isolating (not hard for an aerogel metamaterial out of high bandgap base material).
    A thin layer of intermediately conducting water droplets that heats when lightning strikes (it converts to plasma and may damage the surface) may be avoidable by making the surfaces highly hydrophobic. As a nice side effect combined with small scale active surface movement this can also prevent any ice deposits and thus dangerously high ice loads.


    A&B) A third option is to make the structures switchable between the two extreme states.
    This may allow to extend the weather control to electric aspects of the atmosphere.


    Avoiding long stretches of electrical conductors (km scale) generally seems to be a good idea.
    By exclusively resorting to chemomechanical energy transmission one gets resillience against directly hitting solar storms (giant protuberances directly heading towards earth that would be devastating today due to induction of high voltages in long power lines) and maybe even even resilience against EMPs from not too near atomic blasts (that hopefully will never happen).



    >> Exotic untapped energy forms:


    There's a constant quite high electric field between ground and sky (aerostatic electricity).
    I don't know how much energy is in there and what would happen if large fractions of this electric reservoire where to be extracted or boosted. There's some questionable science going on there with todays pretty limited technology.
    Simple experiment:


    A little more dangerous:


    Slanted horizontal "sails" hanging below the clouds could be used like funnels guiding the rainwater to the "air-mesh-filaments" that then act like eavestroughs in the sky allowing to tap the full potential energy of rainwater. Then we wouldn't depend on a mountains with a suitable high up valley that can be blocked anymore.
    Most of the rain must be redistributed at a lower level (like a shower head in the sky - rain sails ?!) to not negatively influence vegetation. Yes that sounds ridiculous but it might make sense.



    >> The structure of the lifting metamaterial


    For furter discussion of the limits of the technology I need to go a little more into the detail of the structure of the lifting metamaterial. These ultra light metamaterials are made out of cells with thin gas-tight walls and internal 1D trusses (possibly fractaly arranged) that prevent collapse from external pressure. Advanced surface functionalies of the airmesh strings are not located on every cell wall but on the outermost walls of a "sky string" or independent balloon. These outermost surface functionalities are not part of the base metamaterial. The "sky strings" have many basic cells throughought their diamater. The main function of the walls of each cell is just gas exclosure. This compartmentalisation that is finer grained than the whole air string gives some redundance and safety. If the metamaterial is made out of an uncombustible base material like sapphire then there is little to no chance that these structures come crushing down. Nice! The internal trusswork might be equipped with active components to adjust cell sizes a bit such that buoyancy can be adjusted. Too much buoyancy is bad too because of too much upward pulling force on the anchor points.


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