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

Revision as of 12:17, 9 September 2017

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 of 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 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 to the scaling law that surface area per enclosed volume rises with shrinking size thermal isolation shrinks down to very low levels.

When one would keep using technology of early steps of the incremental path (that is remnants of the bootstrapping process) or one starts using technology of the APM unrelated brownian technology path) in advanced gem-gum technology then the 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.

There are likely several cases where one might want 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.
• 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 technology 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.