Elastomeric thermal interface materials with high through‐plane thermal conductivity by 3D printing

Abstract Creating directional heat pathways within polymer‐based elastomeric thermal interface materials (TIMs) using oriented thermally conductive fillers is an effective strategy for developing highly thermally conductive materials. In this work, we report the fabrication of oriented carbon fibers/alumina/silicone gel composites through a three‐dimensional printing method. Because of the high orientation degree of carbon fiber (CF) in the vertical direction, the resulting material demonstrates a through‐plane thermal conductivity of up to 27.77 Wm −1 K −1 with a composition of 21.75 wt% CF and 65.25 wt% spherical alumina, which is over 10 times higher than that of a parallel structure, surpassing the characters in most works of literature. In addition, the TIMs not only show outstanding flexibility (stress 62.27 psi at 30% strain) but also exhibit excellent resilience performance. These findings hold great potential for various scalable thermal and mechanical applications.