biostudies-literatureKeum CLeverhulme TrustNational Research Foundation of Korea (NRF)United States Department of Defense | Defense Advanced Research Projects Agency (DARPA)Deutsche ForschungsgemeinschaftDeutsche Forschungsgemeinschaft (German Research Foundation)Alexander von Humboldt-StiftungUnited States Department of Defense | Defense Advanced Research Projects AgencyNational Science Foundation (NSF)National Research Foundation of KoreaNational Science FoundationEngineering and Physical Sciences Research Council6250https://www.ebi.ac.uk/biostudies/studies/S-EPMC7721873biostudies-literatureUnknown11(1)Despite widespread interest, ultrathin and highly flexible light-emitting devices that can be seamlessly integrated and used for flexible displays, wearables, and as bioimplants remain elusive. Organic light-emitting diodes (OLEDs) with µm-scale thickness and exceptional flexibility have been demonstrated but show insufficient stability in air and moist environments due to a lack of suitable encapsulation barriers. Here, we demonstrate an efficient and stable OLED with a total thickness of ≈ 12 µm that can be fully immersed in water or cell nutrient media for weeks without suffering substantial degradation. The active layers of the device are embedded between conformal barriers formed by alternating layers of parylene-C and metal oxides that are deposited through a low temperature chemicalNature communicationsA substrateless, flexible, and water-resistant organic light-emitting diode.PMC77218731706207EP/L017008/12017R1A6A3A03012331EP/R010595/1404587082RPG-2017-231N66001-17-C-4012Gather MCKwon SMurawski CArcher EMischok AKeum CfalseA substrateless, flexible, and water-resistant organic light-emitting diode.Despite widespread interest, ultrathin and highly flexible light-emitting devices that can be seamlessly integrated and used for flexible displays, wearables, and as bioimplants remain elusive. Organic light-emitting diodes (OLEDs) with µm-scale thickness and exceptional flexibility have been demonstrated but show insufficient stability in air and moist environments due to a lack of suitable encapsulation barriers. Here, we demonstrate an efficient and stable OLED with a total thickness of ≈ 12 µm that can be fully immersed in water or cell nutrient media for weeks without suffering substantial degradation. The active layers of the device are embedded between conformal barriers formed by alternating layers of parylene-C and metal oxides that are deposited through a low temperature chemical2020-01-01T00:00:00Z2020 Dec2025-04-04T11:13:05.663Z2025-04-04T11:13:05.663ZS-EPMC77218733328876910.1038/s41467-020-20016-3