High damping, soft and reprocessable thermal interface materials inspired by the microstructure of skin tissue

Thermal interface materials (TIMs) play a critical role in heat dissipation of modern electronics with their development towards integration and miniaturization. Shock-induced vibration damage is another extremely harmful to electronics, which requires TIMs remarkable damping properties, reprocessability, softness, and high thermal conductivity. However, current TIMs still lack the ability to dampen vibrations and reprocessability, because integrating these properties into one TIM still remains a dilemma. Inspired by the synergistic effects of fiber networks and adipocytes in skin tissue, here, we report on a high damping, soft and reprocessable TIM, by infusing viscous polymer into polybutadiene bottlebrush polymer network meanwhile combing with aluminum nitride filler. The obtained TIMs show damping factor as high as 0.95-1.0 in the frequency range of daily life (1-300 Hz), excellent reprocessability efficiency (92 %), low Young's modulus (55.8 kPa) and thermal conductivity of 2.25 W m-1 K-1. Analyzing the polymer structure and chain dynamics by rheology, broadband dielectric spectroscopy, solid state nuclear magnetic resonance, and FTIR spectroscopy, we confirm that these excellent properties is attributed to the enhanced migration ability of polymer chains, thermally conductive aluminum nitride fillers, and hierarchical hydrogen bonds in the bottlebrush polymer network. We further demonstrate the potential application of the TIMs in heat dissipation of an electronic device under vibrations. The current work provides a unique structure design approach towards high-performance TIMs in shock-resistant electronics.