Elastic Cloaking Material Makes Objects “Unfeelable” - Scientific American

Elastic Cloaking Material Makes Objects “Unfeelable” - Scientific American: The unfeelability cloak is a so-called pentamode metamaterial, an artificial structure that, despite being a solid, can behave like a fluid; although difficult to compress, its shape is otherwise easy to shift. The specific material the researchers devised is a three-dimensional hexagonal lattice reminiscent of a honeycomb, with the rods making up this lattice wider at their middles than at their ends...

The unfeelability cloak does have limits. For instance, the dimensions of the cloak's components have to be designed to specifically match whatever the cloak is hiding. Furthermore, although unfeelability cloaks can hide objects from some pokes and prods, it cannot protect against all of them—one can push on a cloak strongly enough to break it and feel the object it hides.