Direct measurement of electrocaloric effect in P(VDF-TrFE-CFE) film using infrared imaging

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.