Revision as of 19:20, 18 October 2024

Disambiguation page

• Gemstone based metamaterial. Gem-gum as an intentionally paradoxical concrete example of
  a mechanical metamaterial with vastly different properties to the base material. With a catchy name.
• The defining traits of gem-gum-tec. What gem, gum, and gem-gum refers to.
  Gem-gum-tech also called "gem(stone) based APM" here.

⚠️ Related warning

Molecular dynamics simulations are typically run simulating extremely high speeds thus showing jelly like wobbling which would not at all occur when operated at actually proposed (steady state) speeds many orders of magnitude slower.

Be aware that:
⚠️ Diamondoid nanoscale machinery is not at all jelly like floppy
as molecular dynamics simulations may misleadingly suggest.
This is NOT what "gum" in "gem-gum" refers to. High simulations speeds are to blame.
For details see: Misleading aspects in animations of diamondoid molecular machine elements
Actually at nominal proposed speeds (few mm/s)
nanomachinery bends and deflects LESS from machine motions
than even everyday metal macroscale machinery does.
That is due to the scaling law of same relative deflections across scales.

A better intuition: hyper-spring-steel, super-magnets, and sometimes giant forces, all at snail speed

It is still very flexible in terms of stretchability / bendability / strainabbility before breaking
but a better intuition would probably be some sort of hyper-spring-steel (way stiffer than actual spring-steel)
in an environment with super-magnets (way stronger than magnets can physically be) (wihch represent the Van der Waals forces).

Attractive forces are only 1/100 of the internal material forces so one needs to look closely for deformations from them.
Attractive forces can accelerate parts to extremely high speeds though. If not counteracted.
So better not let go of anything or else parts snap together at the speed of bullets which is then
really making them behave like jelly. When looking at the action via slow motion footage that is.
Such brutal snapping generates a lot of heat so is usually to avoid in a dense active machinery system.
Occasional snaps sparse in either space or spare in time (or sparse in both) are ok though.

Only thing where high deformations >1% (but not free wobbling jelly wiggles) may be more regularly visible
is in the transmission of very high (giant) forces (giant for the scale).
That is: In cases where both high power is needed and
heterogeneous mechanical nanoscale transmission is needed (no batching to a larger scale bundle).
Nanoscale bearings need low speeds v (in low mm/s range) to have low frictive losses
(See page: Friction in gem-gum technology) and
with power P equaling to speed v times force F (P=v*F) the force F needs to go up correspondingly.
Then again: Very high forces may also lead to notable frictive losses.
Reciptocative friction due to getting pretty far into the nonlinear elastic range.
It's an optimization problem. See page: Reciprocative friction in gem-gum technology

Not accounted for here is deformations from thermal excitations
which can be quite large especially for very thing and large aspect ratio structures.