(a) Homogeneous structure with isotropic diffusion. (b) Temperature distribution of (a) at a specific moment. (c) and (d) Insulator-conductor-insulator (ICI) structure with anisotropic diffusion in yellow strips (high thermal conductivity) and isotropic diffusion in green areas (low thermal conductivity). (e) and (f) Graded structure with asymmetric diffusion towards the center.