Rice University researchers tested the strength of graphene by firing microscopic projectiles, also referred to as microbullets, at the graphene to determine how difficult it is to penetrate it at the nano level. The researchers used their laser-induced projectile impact test (LIPIT) to shoot a single microscopic sphere with precision at almost 3 kilometers per second at multilayer graphene sheets.
Sheets of various thicknesses up to 300 layers of graphene were tested and regardless of the thickness, the microbullets punctured the graphene. The spheres left a fractured pattern of “petals” around the impact point, signifying the graphene stretched before breaking. This experiment showed that graphene is a stretchy membrane that could lead to it being used for body armor or shielding spacecraft.