Review of elastocaloric cooling systems and their performance

Elastocaloric cooling offers a solid-state alternative to conventional vapor-compression systems by leveraging stress-induced phase transitions in materials like shape-memory alloys (SMAs). This review comprehensively analyzes the development and performance of elastocaloric cooling systems to date. We explain the thermodynamic mechanisms and material requirements, emphasizing challenges such as low latent heat and fatigue life. Subsequently, we categorize and compare thermal contact and heat-transfer-fluid (HTF)-based prototypes, discussing their achievements in temperature span and cooling power. The technical maturity of elastocaloric cooling systems is not comparable to that of commercial vapor-compression systems yet in terms of coefficient of performance (COP) and practicality. We further explore innovative approaches like work recovery, modular design, and novel loading modes (e.g., torsion) to bridge application gaps. The review concludes that elastocaloric cooling holds promise for sustainable refrigeration, though material fatigue, system COP, and heat transfer efficiency remain critical bottlenecks for future research.