Connection method
In the context of APM locking mechanisms are the simplest most compact physical structures that one can built that hold things together.
They can be split into three classes:
- energy barrier locks
- hierarchical locks
- friction locks
[Todo: Improve this article, add info-graphics]
Energy barrier locking
In the macro-scale springs, magnets, gravitation, and almost unused electrostatic attraction belong to this class.
In the nano-scale springs, VdW-force (Van der Walls attraction), chemical bonds and in some cases electrostatic attraction are well usable.
There thermal movement can knock a lock open by probabilistic chance which must be taken under consideration in system design. Energy barriers high enough to effectively prevent opening by chance can be easily reached. [Todo add VdW math example; add more details]
All other locking methods do too display energy barriers but have other more predominant traits.
Hierarchical locking
Something is hierarchical locked when one has to remove a part such that a locking part can be removed. The structure can be disassembled only in a specific order. Hierarchically locked structures can have tree shaped topologies.
If the energy barrier of the lower levels is overcome first it would lead to a complete destruction of the structure.
Friction
Nails and screws base their locking ability on friction but in AP products one usually finds super-lubrication between surfaces.
One can design surfaces such that thay perfectly intermesh but this would effectively create a series of energy barriers (energy barrier locking) in which the barrier adter the first one won't have much use (linear instead of exponential decrease of accidental disassembly probability). Furthermore the energy might be not well recoverable (honstiff hydrogen bonds dissipate power) leading to unnecessary waste heat. Thus the classical nail and screw design probably makes no sense at the nanocosm (To investigate: inhowfar is this statement true?)
Examples
- snap buckles: pure energy barrier locking - zero hierarchical levels
- snap ring: hierarchical locking of at least one but most of the time two layer
- door handle mechanism: hierarchical locking of one layer (with retention of the locking part)
