Phase change materials meet microfluidic encapsulation

Improving the utilization of thermal energy is crucial in the world nowadays due to the 23 high levels of energy consumption. One way to achieve this is to use phase change materials 24 (PCMs) as thermal energy storage media. PCMs can efficiently store and release thermal energy 25 in the form of latent heat, which can be used to regulate temperature or provide heating/cooling in 26 various applications. This can lead to reduced energy consumption and costs, making PCMs a 27 promising solution to promote sustainable energy usage. However, PCMs have limitations like 28 low thermal conductivity, leakage, and corrosion. To overcome these challenges, PCMs are 29 encapsulated into microencapsulated phase change materials (MEPCMs) capsules/fibers. This 30 encapsulation prevents leakage and corrosion issues, ensuring the PCM remains contained and 31 functional, and the microcapsules/fibers act as conduits for heat transfer, enabling efficient 32 exchange between the PCM and its surroundings. Microfluidics-based MEPCMs has attracted 33 intensive attention over the past decade due to the exquisite control over flow conditions and size 34 of microcapsules. This review paper aims to provide an overview of the state-of-art progress in 35 microfluidics-based encapsulation of PCMs. The principle and method of preparing MEPCM 3