Polymer Brush-Assisted Reduction of Contact Thermal Resistance via Interfacial Diffusion of a Liquid Polymer

In this study, we propose a thermal contact strategy to significantly reduce contact thermal resistance by introducing polydimethylsiloxane (PDMS) polymer brushes at the interface between Si substrates. When PDMS oil is sandwiched between the PDMS-brush-modified Si substrates, the contact thermal resistance is reduced by approximately a factor of 5 compared with unmodified Si substrates, achieving values comparable to or lower than those of commercial thermal greases. The time evolution of thermal resistance as a function of molecular weight and temperature suggests that this reduction is consistent with interfacial structural changes associated with the diffusion of PDMS oil into the polymer brush layer. This approach provides a promising route for increasing interfacial thermal transport.