A thin and lightweight miniature loop heat pipe for cooling mobile electronic devices

The escalating thermal challenges in compact electronics necessitate micrometer-scale thermal management innovations. We designed a thin (0.7 mm) and lightweight (3.95 g) miniature loop heat pipe (mLHP). We developed an integrated wick structure with a stepped-serrated main wick and a braided copper wire as the supplementary wick. The copper-based evaporator and polymer-based vapor-liquid lines/condenser are integrated via a solder-free bonding technique to evaporate heat transfer with a maximum equivalent thermal conductivity of 24,449 W/(m·K), exceeding commercial graphene heat spreaders more than 15-fold. Accelerated aging tests at 90°C demonstrate stable performance over 30 days, confirming structural robustness and process stability for scalable mass production.