Magnetic liquid metal core-shell microparticles for dynamic thermal regulation and magnetothermal conversion

This research explores the dynamic thermal regulation of nickel core-EGaIn shell composite microparticles (Ni@EGaIn) through assembly and disassembly under magnetic field, and their high magnetothermal conversion efficiency under alternating magnetic fields. The application of external magnetic field leads to the formation of chain-like Ni@EGaIn micro-assembly with enhanced heat conduction pathways. By adjusting the filler weight percentage to 80 %, Ni@EGaIn particles achieve controlled thermal conductivity ranging from 0.38 to 0.83 W/(m·K) under a 90 mT magnetic field. The Ni@EGaIn composite materials achieve a remarkable thermal switch ratio of 2.19 through magnetic control, surpassing most of previous published results. Such thermal switch can not only be used to design dynamical thermal regulation system for thermal management, but also serve as dynamical temperature-controlled heat-pack system for thermal therapy. Additionally, the Ni@EGaIn composite microparticles exhibit significant magnetothermal conversion efficiency due to the coupling interaction of magnetocaloric effect of Ni and the magnetic induction heating effect of EGaIn, and their biocompatibility allow such composite microparticle to be potentially used as magnetothermal ablation in the biomedicine.