Rational Design of Soft, Thermally Conductive Composite Liquid-Cooled Tubes for Enhanced Personal, Robotics, and Wearable Electronics Cooling

Thermoregulatory garments composed of liquid-cooled plastic tubes have users ranging from astronauts to multiple sclerosis patients and are emerging as a flexible cooling solution for wearable electronics and high-power robotics. Despite the plethora of applications, the current cooling systems are cumbersome to use due to their excessive size. In this work this issue is resolved by developing soft, thermally conductive silicone–aluminum composite tubes. To achieve optimal device performance, the material must be designed to balance the decrease in bulk thermal resistance and the increase in interfacial tube-substrate resistance due to composite stiffening. Thus, to enable the rational design of such tubes, a closed form thermomechanical model that predicts cooling performance as a function of tube geometry and filler fraction is developed and experimentally validated. Predictions via this model and experiments are used to reveal how the tube's geometrical and material design can be adjusted to minimize the required length of tubing and maximize the heat extracted from a metallic surface and skin. Lastly, through a holistic analysis, this work demonstrates that besides significantly increasing overall cooling capability, the use of low-resistance tubing can provide a multifold reduction in the cooling system size and enable novel operating modes.