Microfluidic-Encapsulated Phase Change Fibers with Graphene Coating for Passive Thermal Management

This paper introduces a novel method for encapsulating phase change materials (PCM) into non-toxic, flexible fibers using microfluidic techniques, enhances with graphene coating to passive thermal management. The phase change fibers feature a uniform core-shell structure with a lightweight porous yet dense shell that prevents PCM leakage. The dimensions of the fibers and the ratio of PCM to the shell material can be precisely controlled as required. A graphene coating is applied to the surface of the phase change fiber to enhance its thermal conductivity and emissivity, thereby improving passive cooling performance without compromising the fiber's structural integrity or sealing stability. In particular, thermal management experiments on the electronic components undergoing intermittent operation under periodic thermal load demonstrate that the thermal management by the graphene-coated phase change fiber (GPCF) can effectively reduce both peak and average temperatures of electronic devices. Remarkably, the pure passive cooling without any power consumption based on the GPCF amounts to the performance of the forced air cooling with an airspeed of 0.8 m s^-1, delivering substantial energy savings. The GPCF shows a great potential in thermal management of electronic devices subjected to periodic, short-term high loads, potentially offering significant savings in cooling-related energy consumption.