<p>The article presents a novel and effective heat dissipation technique from electronic devices by using lattice heat sinks. Lattice heat sinks have a larger surface area when compared to the conventional plate fin and pin-fin heat sinks for improved heat dissipation. In this study, the thermal performance of four lattice structures, including the truncated octahedron, Kelvin cell, Weaire-Phelan and fluorite were studied and compared with conventional pin-fin and plate fin heat sinks under identical boundary conditions. This study also compares pure copper and aluminum, along with aluminum–graphene nanocomposites, as the heat sink material. The results show that the thermal performance of Octa and Weaire-Phelan lattice structures are better than conventional heat sinks as the lattice structures yielded 6.5°C lower temperature than the conventional heat sink. Also, the heat sink made from aluminum–graphene composite did better than copper and aluminum by reducing the temperature of about 1.5–2°C. This suggests that an aluminum heat sink made with graphene nanocomposite can improve heat transfer similar to copper and offers lower mass compared with copper.</p>