PDMS-based artificial lung membranes with enhanced permeation to overcome the bottleneck in CO2/O2 selectivity

•PDMS coating thickness is optimized to 376 nm under comprehensive consideration.•The ultimate samples behaved excellent with JO2 = 502 GPU and JCO2 = 4117 GPU.•Hemocompatible tannic acid layer is deposited continuously by Fe(III) chelation.•Membrane area can be saved by about 90 % for general extracorporeal oxygenation.•The increase in permeation successfully neutralized the lacking in selectivity.