Thermomagnetic mechanism of phase change materials for reconfigurable sensing
摘要
Phase change materials (PCMs) offer transformative potential for reconfigurable sensing due to their reversible structural transitions and dramatic property changes. However, their practical implementation remains constrained by reliance on direct Joule heating, which leads to high power consumption, complex electronics, and limited miniaturization—particularly problematic for biomedical, wearable, and harsh-environment applications. This paper proposes a paradigm shift toward contactless, energy-efficient activation using the magneto-caloric effect (MCE) in PCM composites. Through a unified theoretical and experimental analysis, we formalize thermomagnetic coupling mechanisms using Landau free energy, entropy-enthalpy compensation, and magnetocaloric formulations to enable remote phase switching via alternating magnetic fields. Key findings demonstrate that spin-lattice coupling reduces switching energy by up to 45% compared to thermal-only methods, while PCM-based sensors achieve multistate responsivity to thermal and magnetic stimuli with high cyclability (