Compliant Polymeric Sheet‐Based Heat Exchangers

ABSTRACT Heat exchangers provide essential thermal management, spanning from the food industry to chemical processing and beyond; however, they are often made from metals with correspondingly high material and manufacturing costs, along with susceptibility to fouling and corrosion. To address these limitations, researchers have worked to achieve similar performance with heat exchangers made from polymers, but early designs remain expensive, geometrically complex, and limited by low thermal conductivities and operational temperatures. Additionally, previous studies are primarily empirical in nature and lack a sufficient link to theory to enable future design. In this work, we create and characterize heat exchangers made of thin (∼50 µm), transparent polymeric sheets that exhibit heat transfer coefficients up to 2000 W/m ² K while providing a heat exchange capacity per cost 2 to 4 times greater than metal and previous polymer counterparts. These heat exchangers are deployable up to 60 times their initial volume, allowing for compact storage and use in volume‐constrained applications (e.g., takeoff preceding space missions or terrestrial shipping logistics), and their performance can be predicted accurately by an analytical model. This sheet‐based approach enables effective heat exchange using polymeric materials while also providing in‐situ flow visualization, device‐level deployability, and flexibility for compact thermal management.