Toward artificial intelligent self-cooling electronic skins: Large electrocaloric effect in all-inorganic flexible thin films at room temperature

Abstract

Intelligent robots have assisted mankind in achieving and operating thousands of functions, especially with the arrival of the artificial intelligent. However, heat dissipation and thermal management in the intelligent robots remain big challenges, which limit their miniaturization and performance. Electrocaloric (EC) materials, which exhibit temperature change in response to the application or withdrawal of an electric field, open a new strategy for cooling technology and have gained a flurry of research interest in recent years. Toward artificial intelligent self-cooling electronic skins, large-scale flexible materials with high EC effect near room temperature are in demand. Here, we report a large room temperature EC effect in flexible Pb0.82Ba0.08La0.1Zr0.9Ti0.1O3 (PBLZT) inorganic thin films via a transfer-free cost-effective sol-gel process, assisted by unique two-dimensional mica substrates. The maximum adiabatic temperature change and isothermal entropy change of the flexible PBLZT thin films reach to 22.5 K and 25.9 J K− 1 kg− 1 at room temperature. In particular, the flexible PBLZT thin films exhibit a stable EC effect both under bending state and after bending for 20000 times. Our flexible EC materials offer an alternative strategy to the development of cooling technologies for both artificial intelligent robots and personal wearable cooling devices. Keywords: Electrocaloric effect, Ferroelectric thin film, Flexible electronics, Mica, Wearable device