fractal metamaterial redundance principle

thingiverse

A building method for high tolerance against damage. It shows that certain fractal designs have high practical value beyond the obvious application of saving weight. And that when building a device from many identical units with a certain mechanical function (that is a mechanical metamaterial) putting them together naively in a grid configuration (a crystal) is a rather bad option. How the demo works The present 2D example object thats made to illustrate this uses simple springs as instructive placeholders for more complex units. An actual 3D design may have - in place of the springs - things like linear actuators ("motor-muscles" - more below) or interconnected bearing-layers that evenly distribute speed differences ("infinitesimal bearings" - more below). Stick one or multiple of the helpful sabotaging platelets into the springs to block them and see how much actuation length you loose. (The sabotaging-platelets can be tied to the loop on the main part so they dont get lost.) Practiacal applications Concrete application 1:http://apm.bplaced.net/w/index.php?title=Artificial_motor-muscles In a naive bulk block of linear actuator units the lost actuation length adds up almost linearly with the number of units that got stuck. When a fractal design is choosen instead the effect of accumulated damage becomes nonlinear and way smaller for damage-states that are reasonably below 50% destroyed units - in case this state is exceeded the device should probably get repaired or scrapped anyway. Concrete application 2:http://apm.bplaced.net/w/index.php?title=Infinitesimal_bearing In the case of a naive bearing-stack layer disconnection could lead to the majority of speed difference occuring on just this layer leading to excessive heatup there. Fractal design can confine the disconnection to just a small region - keeping the bearing in working order. (Sidenote: Stuck layers could be completely disconnected by some kind overload protection mechanism.) Further notes The reason for "units" to get damaged and stuck can be: ionizing radiation, thermal overheating, dirt and some more. General about nanomechanical metamaterials.http://apm.bplaced.net/w/index.php?title=Metamaterialhttp://apm.bplaced.net/w/index.php?title=Diamondoid_metamaterial Note that the slimmest connection points of the fractal structure must scale proportionally to size to avoid loss of structural integrity with the number of iterations.