Difference between revisions of "Consistent design for external limiting factors"

Latest revision as of 20:32, 14 June 2021

When designing a product one usually wishes that it poses some resilience to environmental influences. A few critical delicate components in a mainly robust system can bog down the whole system. Those components are the weakest links and constitute a bottleneck.

To be able to avoid including components that disproportionately bog-down the whole system one should pair components with their resilience ranges. That is microcomponents could be tagged with links to information (stored somewhere else) describing the allowed operational ranges. Just like the usual "absolute maximum ratings" section in datasheets of todays electronic components. This way one can design a system consistently for a chosen set of the external limiting factors that one requires. Or maximize for one specific spec (performance parameter).

Some examples for external limiting factors are:
temperature T, radiation I , .., acceleration a, pressure p,
chemical resilience when exposed to "surface" (pH, redox-potential), ...

Absolute maximum/minimum Temperature

The allowed temperature range of a whole system is defined by the intersection of all the allowed temperature ranges of the system components. This is of course only true when one assumes thermally equilibrium at the size scale of the whole system. Otherwise one could just protect the sensitive parts by thermally isolating them.

At and below the microscale thermal equilibrium is almost always present (more or less) due very low levels of thermal isolation which are caused by the scaling law that surface area per enclosed volume rises with shrinking size.

When one would keep using technology of early steps of the incremental path to advanced gem-gum technology (that is when one would keep in remnants of the bootstrapping process) in advanced gem-gum technology then this new technology will be bogged-down to an accordingly restricted allowed range of operation temperature. Especially much of the otherwise completely allowed low temperature regime all the way down to zero kelvin will be cut off. The same happens when one would start using technology of the (with gem-gum technology unrelated) brownian technology path.

There are likely several cases where one might want to include temperature sensitive parts and accept the implicated severe cuts in thermal resilience. Some of these could be:

• Entropic batteries – They might work better with smaller molecules that are prone to freeze.
  (In case of an implementation with floppy singly linked chain molecules they likely "feature" high sensitivity to radiation damage beside thermal limits.)
• A situation where thermal capacity bog-down due to integration of thermally sensitive parts does not matter at all are advanced medical nanodevices since those are embedded in a highly temperature sensitive environment anyway.
• ...

The different technology path branches (micro chamber managed brownian technology path vs late stages of incremental path) have vastly different allowed temperature ranges. It is probably advisable to keep track off all the allowed temperature ranges for system components and keep the technology path branches as separate as possible.

Potentially thermally weak structures to look out for could be:

• Very strongly strained parts of crystolecules like cylindric shells. Here less thermal energy is required to overcome the remaining energy barrier and break stuff.
• Bistable structures with low energy barriers.
• Close proximity of atoms that like to form low-energy highly volatile compounds. Many nitrogen atoms close together e.g. may tend to form N₂ gas on heating. Also water and carbon dioxide may form in very harsh thermal conditions.
• Diamond is metastable and can turn into graphite at too high temperatures. Other refractory materials are better suited for high temperature applications.