Anisotropic heat conduction with pyrolytic graphite
Anisotropic Heat Conduction
A thin piece of pyrolytic graphite in thermal contact with a finger cuts through an ice cube. This material, of layered graphene, has excellent electron and thermal conductivity along the layers, but poor conductivity through the layers. This made it good heat shielding material for re-entry vehicles. It's diamagnetic properties are also anisotropic, with a very strong response to fields perpendicular to the layers.