Fracture Diodes: Directional asymmetry of fracture toughness

It is demonstrated here that fracture toughness of a material can be asymmetric, i.e., the resistance of a medium to a crack propagating from right to left can be significantly different from that to a crack propagating from left to right. Such asymmetry is unknown in natural materials, but can be built into artificial materials through the proper control of microstructure.

This paves the way for control of crack paths, where fracture – when unavoidable – can be guided through pre-designed paths to minimize loss of critical components.