Difference between revisions of "Effects of current day experimental research limitations"
From apm
m |
(added notes on diffusion) |
||
Line 8: | Line 8: | ||
* Focus on the for current day directly applicable material science (alloys) | * Focus on the for current day directly applicable material science (alloys) | ||
* Focus on the for material science interesting heavy metallic elements with intersting magnetic properties (f shells) – rare elements ... | * Focus on the for material science interesting heavy metallic elements with intersting magnetic properties (f shells) – rare elements ... | ||
− | * Barely controllable diffusion: on surfaces, in grain boundaries, of dislocations | + | * Barely controllable diffusion: on surfaces, in grain boundaries, of dislocations <br> Partly due to a focus on metals with exotic properties (lower periodic table) as catalysts where valence electron shells are vast and surface diffusion is fast <br>(totally unphysical) visual analogy: Focus on a slippery ice rink rather than a muddy sticky gravel field. |
* High difficulty to achieve very high levels of vacuum (UHV at best – nowhere near [[PPV]]) | * High difficulty to achieve very high levels of vacuum (UHV at best – nowhere near [[PPV]]) | ||
* Immense difficulties with [[SPM]]: getting and keeping tips sharp reliably, limits in imageable hight steps, speed limits, ... | * Immense difficulties with [[SPM]]: getting and keeping tips sharp reliably, limits in imageable hight steps, speed limits, ... |
Revision as of 14:46, 6 July 2021
(wiki-TODO: discuss this)
High level physical effects that misleadingly may suggest infeasibility:
- High wear in MEMS due to "stiction"
- Focus on the for current day directly applicable material science (alloys)
- Focus on the for material science interesting heavy metallic elements with intersting magnetic properties (f shells) – rare elements ...
- Barely controllable diffusion: on surfaces, in grain boundaries, of dislocations
Partly due to a focus on metals with exotic properties (lower periodic table) as catalysts where valence electron shells are vast and surface diffusion is fast
(totally unphysical) visual analogy: Focus on a slippery ice rink rather than a muddy sticky gravel field. - High difficulty to achieve very high levels of vacuum (UHV at best – nowhere near PPV)
- Immense difficulties with SPM: getting and keeping tips sharp reliably, limits in imageable hight steps, speed limits, ...
- Difficulties in designing artificial proteins for binding (not to speak of catalysis)
- ....
Why is should be feasible despite all that
Low level physical effects (from first principles) that prove feasibility:
- Macroscale style machinery at the nanoscale
- A Minimal Toolset for Positional Diamond Mechanosynthesis (paper)
There is also high level evidence but this is weaker:
- Experimental demonstrations of single atom manipulation
- Progess in de-novo protein design and structural DNA nanotechnology
Both low and high level evidence: