Difference between revisions of "Stiffness"
From apm
(→Related: added link to {{stub}} page: Lattice scaled stiffness) |
(→Related: added links to pages * '''Stiffness focusing''' and '''Foldamer technology stiffness nesting''') |
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is of key importance for [[bootstrapping]] the far term goal of advanced [[nanofactories]] through a series of earlier increasingly more powerful atomically precise [[productive nanosystems]]. | is of key importance for [[bootstrapping]] the far term goal of advanced [[nanofactories]] through a series of earlier increasingly more powerful atomically precise [[productive nanosystems]]. | ||
| − | Sufficient stiffness is: | + | Sufficient stiffness (more precisely: [[lattice scaled stiffness]]) is: |
* necessary for sufficient suppression of thermal vibration amplitudes. <br> First sufficiently below the size of pre-produced atomically precise blocks and self-alignment/self-centering slots. <br>Later sufficiently below atom to atom distance to exponentially suppress misplacement errors. | * necessary for sufficient suppression of thermal vibration amplitudes. <br> First sufficiently below the size of pre-produced atomically precise blocks and self-alignment/self-centering slots. <br>Later sufficiently below atom to atom distance to exponentially suppress misplacement errors. | ||
* necessary to archive [[atomically precise positioning]] capability not just [[topological atomic precision]] | * necessary to archive [[atomically precise positioning]] capability not just [[topological atomic precision]] | ||
| Line 14: | Line 14: | ||
== Sufficient lattice scaled stiffness for early low stiffness systems == | == Sufficient lattice scaled stiffness for early low stiffness systems == | ||
| − | Usage of self assembled [[topological atomic precision|atomically precise]] base parts (aka "vitamins") allow for less stringent conditions on stiffness. | + | Usage of self assembled [[topological atomic precision|atomically precise]] base parts (aka "vitamins") allow for less stringent conditions on stiffness. <br> |
Only the '''lattice scaled stiffness''' must be sufficient for block based self centering assembly (which is not really callable "mechanosynthesis" yet). | Only the '''lattice scaled stiffness''' must be sufficient for block based self centering assembly (which is not really callable "mechanosynthesis" yet). | ||
| Line 21: | Line 21: | ||
== How stiffness scales with size == | == How stiffness scales with size == | ||
| − | The [[scaling law]] for stiffness is such that smaller structures have lower stiffness ("softer"). {{wikitodo|Add math and graph.}} Nanoscale diamond e.g. has a compliance that when interpreted at the macroscale lies in a very intuitively understandable range. <br> | + | The [[scaling law]] for stiffness is such that smaller structures have lower stiffness ("softer"). {{wikitodo|Add math and graph.}} <br> |
| + | Nanoscale diamond e.g. has a compliance that when interpreted at the macroscale lies in a very intuitively understandable range. <br> | ||
(See: [[The feel of atoms#Softness]]) | (See: [[The feel of atoms#Softness]]) | ||
| + | |||
| + | Main page: [[Lower stiffness of smaller machinery]] | ||
== Influence of stiffness on manipulator design == | == Influence of stiffness on manipulator design == | ||
The choice of geometric design of nano-manipulators must be taken such that the compliance of the material is compensated for. Long skinny serial mechanics robotic arms (like many industry robots on the macroscale) are a bad choice for the deep nanoscale. Bulky parallel mechanic manipulators are a good choice. | The choice of geometric design of nano-manipulators must be taken such that the compliance of the material is compensated for. Long skinny serial mechanics robotic arms (like many industry robots on the macroscale) are a bad choice for the deep nanoscale. Bulky parallel mechanic manipulators are a good choice. | ||
| + | |||
| + | This may be mostly an issue for [[molecular mills]] in [[assembly level 1]]. | ||
== Influence of stiffness on friction == | == Influence of stiffness on friction == | ||
| Line 33: | Line 38: | ||
This allow for lower levels of friction.<br> | This allow for lower levels of friction.<br> | ||
See: [[Friction in gem-gum technology]] | See: [[Friction in gem-gum technology]] | ||
| + | |||
| + | == The limit to zero stiffness in early systems == | ||
| + | |||
| + | Unfolded foldamers basically have zero stiffness (or rather the concept of stiffness breaks down) due to <br> | ||
| + | their chains of single bonds allowing for quite unconstrained freedom of rotation. | ||
| + | |||
| + | They can attain stiffness when they fold up though by formation of internal bonds like <br> | ||
| + | hydrogen bonds, dative bonds, [[Van der Waals force|Van der Waals bonds]], and sometimes even covalent crosslinking bonds. <br> | ||
| + | Some for this property optimized [[de-novo proteins]] can attain quite significant stiffness. | ||
| + | |||
| + | [[Structural DNA nanotechnology]] is an interesting case. | ||
| + | Even after assembly locally there is practically zero stiffness. | ||
| + | On a larger scale there is stiffness albeit quite low one. | ||
| + | |||
| + | Consequences of this include: | ||
| + | * [[Structural DNA nanotechnology]] features [[topological atomic precision]] but no [[positional atomic precision]]. | ||
| + | * [[Structural DNA nanotechnology]] can on it's own position something to [[positional atomic precision]] only over a time average. | ||
== General == | == General == | ||
| Line 41: | Line 63: | ||
== Related == | == Related == | ||
| − | * [[ | + | * '''[[The defining traits of gem-gum-tec]]''' |
* [[Macroscale style machinery at the nanoscale]] | * [[Macroscale style machinery at the nanoscale]] | ||
* [[Lattice scaled stiffness]] | * [[Lattice scaled stiffness]] | ||
| Line 47: | Line 69: | ||
* [[Gemstone like compound]] | * [[Gemstone like compound]] | ||
* [[High pressure]] | * [[High pressure]] | ||
| + | * '''[[Energy, force, and stiffness]]''' | ||
| + | * [[Lower stiffness of smaller machinery]] – a [[scaling law]] | ||
| + | * '''[[Same relative deflections across scales]]''' | ||
| + | * [[Sloppy finger problem]] | ||
| + | ---- | ||
| + | * '''[[Stiffness focusing]]''' and '''[[Foldamer technology stiffness nesting]]''' | ||
| + | ---- | ||
| + | * [[Characteristic bending length]] | ||
| + | * [[Spiroligomers]] | ||
| + | * [[Highly polycyclic small molecule]] | ||
== External links == | == External links == | ||
| Line 56: | Line 88: | ||
* Blogpost 2009-02-20: [https://web.archive.org/web/20160331095526/http://metamodern.com/2009/02/20/nanomaterials-for-nanomachines/] <br>"Nanomachines, Nanomaterials, and K<sub>lm</sub>" <br>Subtitle: "Toward Advanced Nanotechnology: Nanomaterials (5)" | * Blogpost 2009-02-20: [https://web.archive.org/web/20160331095526/http://metamodern.com/2009/02/20/nanomaterials-for-nanomachines/] <br>"Nanomachines, Nanomaterials, and K<sub>lm</sub>" <br>Subtitle: "Toward Advanced Nanotechnology: Nanomaterials (5)" | ||
* Blogpost 2009-02-15: [https://web.archive.org/web/20160327213120/http://metamodern.com/2009/02/15/nanomaterials-nanostructures-and-stiffness/]. <br>"Nanostructures, Nanomaterials, and Lattice-Scaled Stiffness"<br> Subtitle: "Toward Advanced Nanotechnology: Nanomaterials (4)" <br>(Note: the uncrecovered direct link [http://metamodern.com/2009/02/15/nanomaterials-nanostructures-and-stiffness/] works for this specific post '''BUT'''<br> many internal links are broken. Database damage presumably?) | * Blogpost 2009-02-15: [https://web.archive.org/web/20160327213120/http://metamodern.com/2009/02/15/nanomaterials-nanostructures-and-stiffness/]. <br>"Nanostructures, Nanomaterials, and Lattice-Scaled Stiffness"<br> Subtitle: "Toward Advanced Nanotechnology: Nanomaterials (4)" <br>(Note: the uncrecovered direct link [http://metamodern.com/2009/02/15/nanomaterials-nanostructures-and-stiffness/] works for this specific post '''BUT'''<br> many internal links are broken. Database damage presumably?) | ||
| + | |||
| + | === Wikipedia === | ||
| + | |||
| + | * [https://en.wikipedia.org/wiki/Persistence_length Persistence length] – See: [[Characteristic bending length]] | ||
| + | ---- | ||
| + | * [https://en.wikipedia.org/wiki/Stiffness Stiffness] | ||
| + | * [https://en.wikipedia.org/wiki/Hooke%27s_law Hook's law] | ||
| + | * [https://en.wikipedia.org/wiki/Young's_modulus Young's modulus]] | ||
| + | ---- | ||
| + | Some of the German pages seem better as of 2022: | ||
| + | * Stiffness – [https://de.wikipedia.org/wiki/Steifigkeit Steifigkeit] | ||
| + | * Spring constant – [https://de.wikipedia.org/wiki/Federkonstante Federkonstante] | ||
| + | * Elastic modulus – [https://de.wikipedia.org/wiki/Elastizit%C3%A4tsmodul Elastizitätsmodul] | ||
Latest revision as of 12:42, 16 November 2024
the less soft the nanomachinery the less imprecise the mechanosynthesis
Gradually introducing sufficient stiffness into atomically precise structures is of key importance for bootstrapping the far term goal of advanced nanofactories through a series of earlier increasingly more powerful atomically precise productive nanosystems.
Sufficient stiffness (more precisely: lattice scaled stiffness) is:
- necessary for sufficient suppression of thermal vibration amplitudes.
First sufficiently below the size of pre-produced atomically precise blocks and self-alignment/self-centering slots.
Later sufficiently below atom to atom distance to exponentially suppress misplacement errors. - necessary to archive atomically precise positioning capability not just topological atomic precision
- necessary for making force applying mechanosynthesis possible
- one reason for the choice of gemstone like compounds as good base material / far term target material
Contents
Sufficient lattice scaled stiffness for early low stiffness systems
Usage of self assembled atomically precise base parts (aka "vitamins") allow for less stringent conditions on stiffness.
Only the lattice scaled stiffness must be sufficient for block based self centering assembly (which is not really callable "mechanosynthesis" yet).
(wiki-TODO: Add external link to lattice scaled stiffness explanation page.)
How stiffness scales with size
The scaling law for stiffness is such that smaller structures have lower stiffness ("softer"). (wiki-TODO: Add math and graph.)
Nanoscale diamond e.g. has a compliance that when interpreted at the macroscale lies in a very intuitively understandable range.
(See: The feel of atoms#Softness)
Main page: Lower stiffness of smaller machinery
Influence of stiffness on manipulator design
The choice of geometric design of nano-manipulators must be taken such that the compliance of the material is compensated for. Long skinny serial mechanics robotic arms (like many industry robots on the macroscale) are a bad choice for the deep nanoscale. Bulky parallel mechanic manipulators are a good choice.
This may be mostly an issue for molecular mills in assembly level 1.
Influence of stiffness on friction
More stiffness causes less or harder to excite degrees of freedom for thermal motion.
This allow for lower levels of friction.
See: Friction in gem-gum technology
The limit to zero stiffness in early systems
Unfolded foldamers basically have zero stiffness (or rather the concept of stiffness breaks down) due to
their chains of single bonds allowing for quite unconstrained freedom of rotation.
They can attain stiffness when they fold up though by formation of internal bonds like
hydrogen bonds, dative bonds, Van der Waals bonds, and sometimes even covalent crosslinking bonds.
Some for this property optimized de-novo proteins can attain quite significant stiffness.
Structural DNA nanotechnology is an interesting case. Even after assembly locally there is practically zero stiffness. On a larger scale there is stiffness albeit quite low one.
Consequences of this include:
- Structural DNA nanotechnology features topological atomic precision but no positional atomic precision.
- Structural DNA nanotechnology can on it's own position something to positional atomic precision only over a time average.
General
- The SI unit of stiffness is newtons per square meter (N/m2)
- The inverse of stiffness is called compliance. Not softness which would be the inverse of hardness.
Related
- The defining traits of gem-gum-tec
- Macroscale style machinery at the nanoscale
- Lattice scaled stiffness
- Mechanosynthesis
- Gemstone like compound
- High pressure
- Energy, force, and stiffness
- Lower stiffness of smaller machinery – a scaling law
- Same relative deflections across scales
- Sloppy finger problem
External links
Related pages from
Eric Drexler's blog: Metamodern – The Trajectory of Technology
Recovered with the internet archives wayback machine.
(More recovered pages from this blog can be found here: Eric Drexler's blog partially dug up from the Internet Archive)
- Blogpost 2009-02-20: [1]
"Nanomachines, Nanomaterials, and Klm"
Subtitle: "Toward Advanced Nanotechnology: Nanomaterials (5)" - Blogpost 2009-02-15: [2].
"Nanostructures, Nanomaterials, and Lattice-Scaled Stiffness"
Subtitle: "Toward Advanced Nanotechnology: Nanomaterials (4)"
(Note: the uncrecovered direct link [3] works for this specific post BUT
many internal links are broken. Database damage presumably?)
Wikipedia
Some of the German pages seem better as of 2022:
- Stiffness – Steifigkeit
- Spring constant – Federkonstante
- Elastic modulus – Elastizitätsmodul
