Electrocaloric^1,2 and electrostrictive^3,4 effects concurrently exist in dielectric materials. Combining these two effects could achieve the lightweight, compact localized thermal management that is promised by electrocaloric refrigeration⁵. Despite a handful of numerical models and schematic presentations^6,7, current electrocaloric refrigerators still rely on external accessories to drive the working bodies^8,9,10 and hence result in a low device-level cooling power density and coefficient of performance (COP). Here we report an electrocaloric thin-film device that uses the electro-thermomechanical synergy provided by polymeric ferroelectrics. Under one-time a.c. electric stimulation, the device is thermally and mechanically cycled by the working body itself, resulting in an external-driver-free, self-cycling, soft refrigerator. The prototype offers a directly measured cooling power density of 6.5 W g⁻¹ and a peak COP exceeding 58 under a zero temperature span. Being merely a 30-µm-thick polymer film, the device achieved a COP close to 24 under a 4 K temperature span in an open ambient environment (32% thermodynamic efficiency). Compared with passive cooling, the thin-film refrigerator could immediately induce an additional 17.5 K temperature drop against an electronic chip. The soft, polymeric refrigerator can sense, actuate and pump heat to provide automatic localized thermal management.

电热^1,2效应和电致伸缩^3,4效应同时存在于介电材料中。将这两种效应结合起来可以实现电热制冷⁵所承诺的轻质、紧凑的局部热管理。尽管有一些数值模型和示意图^6,7，当前的电热制冷机仍然依赖外部配件来驱动工作机构^8,9,10，因此导致设备级冷却功率密度和性能系数 (COP) 较低。在这里，我们报告了一种电热薄膜器件，该器件利用聚合物铁电体提供的电热机械协同作用。在一次性交流电刺激下，该装置通过工作体本身进行热循环和机械循环，从而形成一种免外部驱动的、自循环的软冰箱。该原型机的直接测量冷却功率密度为 6.5 W g ^-1，在零温度跨度下峰值 COP 超过 58。该器件仅是一块 30 µm 厚的聚合物薄膜，在开放环境中在 4 K 温度跨度下实现了接近 24 的 COP（热力学效率为 32%）。与被动冷却相比，薄膜制冷机可以立即使电子芯片额外降温 17.5 K。这种柔软的聚合物冰箱可以感应、驱动和泵送热量，以提供自动局部热管理。