Direct measurement of electrocaloric effect in P(VDF-TrFE-CFE) film using infrared imaging
Ashwath Aravindhan, Pierre Lhéritier, Àlvar Torelló, Uroš Prah, Youri Nouchokgwe, Asmaa El Moul, Xavier Chevalier, Fabrice Domingues Dos Santos, Emmanuel Defaÿ, Veronika Kovacova
Abstract
Poly (vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) P(VDF-TrFE-CFE) is a relaxor ferroelectric polymer, which exhibits a temperature-independent electrocaloric effect at room temperature. In this work, the electrocaloric effect in P(VDF-TrFE-CFE) film was directly analysed using infrared imaging. P(VDF-TrFE-CFE) 64.8%/27.4%/7.8% (in mole) film of (15 ± 1) μm thickness was deposited on polyethylene naphthalate substrate. Direct ECE of P(VDF-TrFE-CFE) film was measured from 15 to 35 °C at different electric fields. A maximum adiabatic temperature change (ΔTad) of 3.58 K was measured during the cooling cycle at a field of 100 V/μm at 30 °C. Finite element analysis of temperature dissipation through the sample estimated that the actual temperature change within P(VDF-TrFE-CFE) film was 4.3 K. Despite the thermal mass of the substrate, a substantial ECE was observed in P(VDF-TrFE-CFE) films. This electrocaloric terpolymer composition could be of interest for electrocaloric cooling applications.