Preparation and surface modification of vertically structured indium/graphite elastomer thermal pad for effective heat dissipation

In recent years, with the increasing integration level of modern electronics and the rise of artificial intelligence (AI) models, the development of advanced thermal interface materials (TIMs) for heat dissipation in high-power chips has become indispensable. Here in this work, based on the intrinsic high thermal conductivity of graphite and indium, the densely aligned vertical indium/graphite (@VInGr) thermal pad is prepared. The @VInGr exhibites a high through plane thermal conductivity (κ_⊥ of 103.6 W/m·K) and low compression modulus (1.45 Mpa). Based on the excellent wettability of liquid metal (LM) on indium, we performed surface modification to reduce the thermal resistance and further improve heat dissipation efficiency. As a result, due to the formation of a ‘solid-liquid’ interface bridge, the total thermal resistance (R_total) decreased from 0.58 cm² K/W to 0.38 cm² K/W. Practical heat dissipation tests shows that when LM/@VInGr/LM is used as a thermal interface material (TIM), the temperature of LED bulb significantly decreases compared to commercial thermal pads (decreased: ΔT = 8.6 °C). These results demonstrate that the surface modified @VInGr composite thermal pad has pioneered a new TIM for effective thermal management in modern high-power electronics.