Chip cooling with manifold-capillary structures enables 10⁵ COP in two-phase systems

The exploration of two-phase flow and heat transfer within confined spaces has revealed its potential to mitigate formidable heat dissipation in various applications, such as thermal management in advanced electronic devices. However, the inherent, remarkable disparity between the specific volume of two phases, coupled with size effects on liquid/vapor interactions, occasionally results in uncontrolled multiphase flow, increased pressure drop, and reduced critical heat flux. Here, we present an innovative cooling solution using a microchannel heat sink with micropillars as the capillary structure to enhance thin-film evaporation, thus controlling the chaotic two-phase flow to some extent and mitigating local dry-out issues, along with three-dimensional (3D) manifold fluidic passages for efficient distribution of coolant into the microchannels. We demonstrate a significant increase in the coefficient of performance, reaching up to 10⁵. Our approach not only sets a new benchmark for cooling efficiency but also opens pathways for thermal management in next-generation, high-performance electronic systems.