Self-oscillating polymeric refrigerator with high energy efficiency.

Autor: Han, Donglin, Zhang, Yingjing, Huang, Cenling, Zheng, Shanyu, Wu, Dongyuan, Li, Qiang, Du, Feihong, Duan, Hongxiao, Chen, Weilin, Shi, Junye, Chen, Jiangping, Liu, Gang, Chen, Xin, Qian, Xiaoshi
Zdroj: Nature; May2024, Vol. 629 Issue 8014, p1041-1046, 6p
Abstrakt: Electrocaloric1,2 and electrostrictive3,4 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 presentations6,7, current electrocaloric refrigerators still rely on external accessories to drive the working bodies8–10 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.We report on a near-zero-power flexible heat pump that uses both electrocaloric and electrostrictive properties of a tailored polymer to create a chip-scale refrigerator device. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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