Stretchable and durable Parylene/PEDOT:PSS/Parylene multi-layer induced by plastic deformation for stretchable device using functionalized PDMS

Currently, electronic components having wavy structures are being actively studied because such wavy structures exhibit stretchability through flattening under stretching. The buckling of a thin film on an elastomer is an easy and inexpensive approach of creating a wavy structure and has attracted considerable attention. Despite its simplicity and easiness, the requirement of stretchers during film deposition limits fabrication methods, such as spin-coating and printing methods, and hinders their application in industry. Here, we eliminated the requirement of stretchers during film deposition by utilizing plastic deformation of the thin film and extending methods of developing a wrinkle structure. We used poly-3,4-ethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS), the most widely used conductive polymer, as a thin film and adopted its stretchable wrinkle structure for stretchable electronic devices. The stretchability and durability of PEDOT:PSS were enhanced by sandwiching the PEDOT:PSS layer between two Parylene layers. The PEDOT:PSS layer was conductive at a stretch of up to 170%, and the change in resistance was less than 10% after 4000 cyclic loads. Additionally, we demonstrated a new concept of a flexible and stretchable light emitting device using the proposed Parylene/PEDOT:PSS/Parylene multi-layer and functionalized polydimethylsiloxane.