Photolithographic Patterning of Polypyrrole on Elastic Polydimethylsiloxane for Flexible and Conformal Organic Electronics

By preparing covalently linked polypyrrole (PPy) on elastic polydimethylsiloxane (PDMS) prior to the deposition of photoresist, the photolithographic PPy patterns on PDMS (PPy/PDMS) are fabricated, with high optical transparency up to 83% over the visible spectrum, excellent cyclic bending stability, high conformability, and the precision down to $3~\mu \text{m}$ . The photolithographic PPy/PDMS electrodes combined with a mechanical lamination strategy, enable the fabrication of all-solution-processed all-organic flexible and conformal organic transistor arrays. Benefiting from good conductivity, high mechanical stability and environmental stability of the electrodes, the transistors exhibit maximum mobility of 0.2 cm $^{{2}}\text{V}^{-{1}}\text{s}^{-{1}}$ , and extremely stable electrical properties on different 3D sphere surfaces till 99% humidity. These results demonstrate the promising application potential of the PPy/PDMS electrodes in skin-like wearable and implantable organic electronics.