<p>➀ Fraunhofer IAP develops ultrathin electrocaloric polymer films (4 micrometers) for refrigerant-free heating/cooling systems, targeting applications in vehicles, electronics, and laser systems;</p><p>➁ These polymers use electric fields to generate rapid temperature changes, enabling energy-efficient heat pump designs with alternating warm/cold zones;</p><p>➂ Multilayer stacking and material optimization enhance performance, offering eco-friendly alternatives to compressor-based refrigeration in the ElKaWe flagship project.</p>