High thermal conductivity and remarkable damping composite gels as thermal interface materials for heat dissipation of chip

Abstract

The emerging applications of composite gels as thermal interface materials (TIMs) for chip heat dissipation in intelligent vehicle and wearable devices require high thermal conductivity and remarkable damping properties. However, thermal conductivity and damping properties are usually correlated and coupled each other. Here, inspired by Maxwell theory and adhesion mechanism of gecko's setae, we present a strategy to fabricate polydimethylsiloxane-based composite gels integrating high thermal conductivity and remarkable damping properties over a broad frequency and temperature range. The multiple relaxation modes of dangling chains and the dynamic interaction between the dangling chains and aluminum fillers can efficiently dissipate the vibration energy, endowing the composite gels with ultrahigh damping property (tan δ > 0.3) over a broad frequency (0.01 – 100 Hz) and temperature range (–50 – 150 °C), which exceeds typical state-of-the-art damping materials. The dangling chains also comfort to the interfaces between polymer matrix and aluminum via van der Waals interaction, resulting in high thermal conductivity (4.72 ± 0.04 W m–1 K–1). Using the polydimethylsiloxane-based composite gel as TIMs, we demonstrate effective heat dissipation in chip operating under vigorous vibrations. We believe that our strategy could be applied to a wide range of composite gels and lead to the development of high-performance composite gels as TIMs for chip heat dissipation.

Keywords

• Thermal interface materials
• Composite gels
• Damping
• Thermal conductivity
• Dangling chains