In general, the adhesive structure and mechanism of an animal could be connected to the micro-structured roughness of natural substrata (e.g. plant surfaces) in the natural environment.
This manuscript focuses on the nanometer scale, which is involved in everything from gecko spatulae to the waxy nanotubules of the lotus leaf, to the fibroin protein materials that constitute spider silks.
In general, spider silks display superior mechanical properties, but only in the last few decades, researchers investigated various types of silks and evaluated their very different mechanical properties. The dragline and the flag silks (or radial and circumferential) of orb weaving spiders have been characterized in scientific literature while, to our knowledge, few studies have been conducted on bundles, which connect the cocoons of Meta menardi to the ceiling of caves.
E. Lepore is Senior Postdoctoral Fellow and N. Pugno is Full Professor of Solid and Structural Mechanics at the University of Trento.