Unraveling topology-driven flow characteristics and thermal-hydraulic synergy in TPMS microchannel heat sinks for chip cooling

Triply periodic minimal surface (TPMS) structures offer strong potential for high-heat-flux thermal management owing to their large specific surface area, smooth curvature, and interconnected flow pathways. However, the microscale convective heat transfer of TPMS microchannel heat sinks (MCHSs) remains insufficiently understood. In this study, the thermal-hydraulic performance of Diamond- and Gyroid-TPMS MCHSs is systematically investigated to clarify topology-dependent flow and heat transfer mechanisms. The effect of solid volume fraction ( V s = 20%–40%) are evaluated and benchmarked against conventional rectangular microchannel heat sinks (RMCHS). The results show that the Diamond-TPMS (D-TPMS) topology induces stronger secondary flows, vortex formation and fluid mixing, whereas the Gyroid-TPMS (G-TPMS) structure promotes smoother, more streamwise-aligned flow. Across all investigated V s , both TPMS MCHSs substantially outperform the RMCHS. The D-TPMS and G-TPMS achieve average convective heat transfer coefficient enhancements of 677.8%–809.8% and 324.0%–417.2%, respectively, with corresponding performance evaluation coefficient ( PEC ) of 3.44–5.15 and 2.60–3.53 under inlet temperature ( T in ) = 298 K, Reynolds number ( Re ) = 200 and heat flux ( q w ) = 300 W/cm 2 . To demonstrate manufacturability and validate the numerical model, copper TPMS prototypes were fabricated using an additive manufacturing (AM)-assisted investment casting method. The experimental results agree well with the numerical predictions, with maximum deviations of 0.96% for wall temperature and 34.6% for pressure drop. This work elucidates topology-dominated microscale heat transfer in TPMS microchannels and offers valuable guidance for high-power electronic devices.