Thin　film　encapsulation　(TFE)　with　high　barrier　performance　and　mechanical　reliability　is　essential　and　challenging　for　the　reliable　operation　of　flexible　organic　light-emitting　diodes　(OLEDs).　To　break　the　trade-off　relationship　between　high　flexibility　and　low　permeability,　this　work　proposed　an　Al2O3/acrylic　multi-layered　structure　with　wavy　stacking　interfaces　to　reduce　the　tensile　strain　of　the　brittle　Al2O3　film　under　bending.　It　was　found　from　simulation　analysis　that　3-dyad　wavy　Al2O3/acrylic　multi-layered　structures　with　periods　in　the　ranges　of　500–1500　nm　and　amplitudes　in　the　ranges　of　600–1600　nm　were　preferred　due　to　a　smaller　maximum　stress　under　bending.　A　novel　approach　to　generate　wavy　structures　with　controllable　periods　and　amplitudes　was　proposed　by　combining　argon　plasma　treatment　and　soft-lithography.　The　findings　suggest　that　the　water　vapor　transmission　rate　(WVTR)　of　a　3-dyad　wavy　Al2O3/acrylic　multi-layer　was　3.18　×　10−5　g/m2/day　after　100-iteration　bending　with　the　bending　radius　of　1　cm,　corresponding　to　the　tensile　strain　exceeding　1.09%.　The　lifetime　of　OLED　encapsulated　using　corresponding　Al2O3/acrylic　multi-layers　with　wavy　structures　and　under　the　same　bending　condition　was　around　50　h,　showing　a　40%　increase　compared　to　that　without　wavy　structures.　The　wavy　structures　can　improve　the　mechanical　properties　of　Al2O3/acrylic　remarkably.　©　2023　Elsevier　B.V.