Supercritically superlubric - Revision history

Apm: /* Overpowered remnant static friction for the possibly subcritical superlubrication cases */ added == Challenge of achieving the effect == and cleanups

2026-05-03T16:11:07Z

Overpowered remnant static friction for the possibly subcritical superlubrication cases: added == Challenge of achieving the effect == and cleanups

← Older revision		Revision as of 18:11, 3 May 2026
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	* reduction of waviness from cange of uinterface distance and/or pressure		* reduction of waviness from cange of uinterface distance and/or pressure
	* raising of temperatue so log the matrials and surfacs still tolerate it		* raising of temperatue so log the matrials and surfacs still tolerate it

			== Challenge of achieving the effect ==

			The effect described here mayb be somewhat challenging to realize. <br>
			Needed is a very small surface contact area <br>
			yet still big enough for superbubricity <br>
			and that at sufficiently high temperatues. <br>

	== Overpowered remnant static friction for the possibly subcritical superlubrication cases ==		== Overpowered remnant static friction for the possibly subcritical superlubrication cases ==

	A more interesting and practically relevant question ~~is usually~~ <br>		'''A usually more interesting and practically relevant question:''' <br>
	~~for~~ subcritical superlubric cases or even non subperllubric cases <br>		For subcritical superlubric cases or even non subperllubric cases: <br>
	~~if or if not the~~ [[vdW suck-in]] forces do overpower ~~<br>~~		'''Do [[vdW suck-in]] forces overpower the remnant sliding energy potential waviness or not.''' <br>
	the remnant sliding energy potential waviness. <br>		In other words: Is the [[vdW slide-on threshold]] exceded or not? <br>

	== Related ==		== Related ==

Apm: /* Not truly zero friction. => Actually zero static(!) friction after all. */

2026-05-03T16:00:50Z

Not truly zero friction. => Actually zero static(!) friction after all.

← Older revision		Revision as of 18:00, 3 May 2026
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	That is actually only true … <br>		That is actually only true … <br>
			* speed dependent friction
	* for the broad concept of suprlubricity.		* for the broad concept of suprlubricity.
	* for pretty much all what is today (2026) expermentally acessible.		* for pretty much all what is today (2026) expermentally acessible.

			We have an exception for static friction in as of yet (2026) <br>
			likely experimentaly still inacessible systems.

	== The qualitative change ==		== The qualitative change ==

Apm: /* Possible criticism of the concept */

2026-05-03T15:57:33Z

Possible criticism of the concept

← Older revision		Revision as of 17:57, 3 May 2026
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	One could argue that diffusion happens at low temperatures and high energy barriers too just exponentially slower. <br>		One could argue that diffusion happens at low temperatures and high energy barriers too just exponentially slower. <br>
	So in that sense static friction is always zero. That's a bit absurd though. ~~[[wikitodo\|Max fore threshold?]]~~ <br>		So in that sense static friction is always zero. That's a bit absurd though. <br>

	~~One~~ could look if there is an acceleration happening but this goes quickly into dynamic fricion instead.		In this case there is a clead distinction between <br>
			– Diffusiion direction probabilty being skewed by force and <br>
			– static friction being overcome startung a maningfully fast motion. <br>

			Latter case one could look if there is an acceleration happening <br>
			but this goes quickly into dynamic fricion instead. <br>

			There sould be a point where these two start blurring together.<br>
			This might not exactly coincide with the criticality criterion here, but is should roughly. <br>

	== Enginering / encountering supercritical superlubricity ==		== Enginering / encountering supercritical superlubricity ==

Apm: basic page

2026-05-03T15:49:02Z

basic page

New page

{{site specific term}}
Characteristic thermal energy kT exceeding the remnant energy waviness of the energy potential along the sliding direction(s).

== Not truly zero friction. => Actually zero static(!) friction after all. ==

The reader might have encountered statements like: 
''"Superlubricity is not like superconductivity as there is no sudden qualitatye jump to unmeasurably small friction"''

That is actually only true … 
* for the broad concept of suprlubricity.
* for pretty much all what is today (2026) expermentally acessible.

== The qualitative change ==

The "supercritical" in the title refers to characteristic thermal energy kT exceeding lsiding ebnergy potential waviness.

There is a qualitative change happening 
'''when the thermal enegy kT suddenly exceeds the remnant energy waviness of the surface contact sliding potential'''. 
Causing static friction to go to literally zero or rather making it stop to make sense. 
Granted while a qualitatibve change not a very sharp and sudden change. 

Even if there is no force present at all the sliding interface diffuses around. 
So every epsilon of force (no matter how small) will eventualy lead to a motion in this driving direction. 
The hallmark of zero static friction. 

== Possible criticism of the concept ==

One could argue that diffusion happens at low temperatures and high energy barriers too just exponentially slower. 
So in that sense static friction is always zero. That's a bit absurd though. [[wikitodo|Max fore threshold?]] 

One could look if there is an acceleration happening but this goes quickly into dynamic fricion instead.

== Enginering / encountering supercritical superlubricity ==

Supercriticality of superlubricity (as defined here) can be ebbginnered or happen by …
* reduction of waviness from more incommensural interface (rotations, other sirface pairings)
* reduction of waviness from cange of uinterface distance and/or pressure
* raising of temperatue so log the matrials and surfacs still tolerate it

== Overpowered remnant static friction for the possibly subcritical superlubrication cases ==

A more interesting and practically relevant question is usually 
for subcritical superlubric cases or even non subperllubric cases 
if or if not the [[vdW suck-in]] forces do overpower 
the remnant sliding energy potential waviness. 

== Related ==

* [[Superlubricity]]
* [[Design of crystolecules]]