We discovered that it is possible to produce mechanical structures with regular pentagonal totally or partially void dodecahedrons without any void between dodecahedron elements (Drawing 1).
The tough of the structure versus used matter amount and taken volume is optimized and the best possible and very better than honeycomb structures used for example in aerospace industry.
Microscopic structures made of molecular, small microscopic segments or crystallographic regular dodecahedron lattices is also possible and can produce very though material versus weight of the material.
In the aim to produce that mechanical structure it is possible to glue the regular dodecahedron elements faces. It is also possible to make tips or spikes or solder points on faces of the regular pentagonal dodecahedrons in the aim to produce welding (solder) with electrical current passing throw the metallic dodecahedron and the metallic mechanical structure in construction.