A group of researchers discovered the secret of nuts and their shells, which are sometimes very difficult to break. The study appeared in Advanced Science.
Walnuts have an extremely strong shell made from layers of cells that in turn have very hard walls and separation fibers that form a polygonal pattern. The researchers have in particular analyzed the shells of classic walnuts, those produced by plants of the genus Juglans, whose shell is made of very dense tissue in which the same forms that the cells create are difficult to recognize even with a high degree of magnification.
The researchers isolated the single cells of these shells thanks to a particular organic polymer and examined them with the microscopes. They identified a new type of cell, never classified before, which they called the polylobate sclereid cell (polylobate sclereid).
It is a particular cell that has irregular lobes and contours sometimes concave, sometimes convex. The result is a scheme in which each cell has 14 other cells close together in a very complex scheme which, however, makes the shell very strong, almost woody, and resistant to traction.
The results obtained could be of help in creating an equally light and resistant material based on the same type of structure.