Quasi-elastic liquid metal thermal interface material with varying surface wettability for heat dissipation from vibrating and deforming heat sources

In the thermal management of electrical components, the highest thermal resistance typically occurs between the heat sources and heat-dissipating parts. Thermal interface materials (TIMs) are used to reduce the thermal resistance between these parts, but for conventional TIMs the thermal resistance increases upon repeated deformation of the heat source due to vibration and thermal expansion/contraction. To overcome this challenge, we have developed a novel TIM system that maintains low thermal resistance even after repeated deformation by using a liquid metal (eutectic gallium–indium) as a quasi-elastically deformable material with a surface possessing regions of different wettability. The proposed TIM prevents the increase in thermal resistance caused by voids generated during deformation and exhibits the lowest thermal resistance when used with vibrating and deforming heat sources compared with various commercial TIMs, with no change in thermal resistance after repeated compression to 65% of the initial thickness. This TIM is highly promising for heat sources subject to vibration and thermal expansion, such as automotive electrical materials and central processing units.