Numerical Simulation of Heat Transfer and Mechanical Stress in Microencapsulated Phase Change Materials for Wearable Textile Applications

Abstract

This paper presents a finite element simulation study of microencapsulated phase change materials (MPCMs) developed for integration into wearable thermoregulating textiles. Using COMSOL Multiphysics 6.2, heat transfer and mechanical stress analyses were conducted on n-octadecane/melamine-formaldehyde (MF) microcapsules with diameters ranging from 1 to 30 µm and shell thicknesses of 30 nm and 70 nm. Thermal simulations reveal that melting time increases with capsule diameter and wall thickness, while structural simulations demonstrate an inverse relationship between capsule diameter and von Mises stress under compressive loads of 1000–2000 µN. By overlaying both datasets, an optimisation zone was identified at a diameter of 5–6 µm with a 70 nm MF shell, balancing thermal responsiveness with mechanical integrity under textile application conditions. These simulation results guided the physical fabrication and characterisation of MPCMs for a neck cooling collar designed to assist athletes’ post-exercise recovery.