Architecting optimized thermal conduction pathways in colonnade-structured polydimethylsiloxane-based thermal...

The rapid rise in chip heat generation places increasing demands on thermal interface materials (TIMs), requiring higher thermal conductivity and more efficient thermal conduction pathways. Here, we introduce a new design strategy for TIMs that directs heat transfer in three stages: horizontal distribution, vertical transfer, and horizontal dissipation. Using the direct ink writing three-dimensional printing technique, we fabricate polydimethylsiloxane (PDMS)-based TIMs with a colonnade-inspired architecture. The top and bottom "corridors" are formed from a boron nitride nanosheet (BNNS)/PDMS composite, where BNNS fillers are aligned in the in-plane direction to enhance lateral heat conduction. The central "pillar" layer is composed of a reduced graphene oxide (rGO)/PDMS composite, with rGO fillers aligned in the through-plane direction to promote vertical heat transfer. Compared with conventional PDMS-based TIMs containing randomly dispersed fillers or sandwich structures with only in-plane alignment, our prepared colonnade-structured PDMS-based TIMs demonstrate significantly improved thermal conductivity and reduced thermal resistance for interfaces.