Vertical-Structure Overcomes the Strain Limit of Stretchable Organic Electrochemical Transistors.

Intrinsically stretchable organic electrochemical transistors (IS-OECTs), utilizing organic mixed ionic-electronic conductors (OMIECs) as their channel materials, have drawn great attention recently because of their potential to enable seamless integration between bioelectronic devices and living systems. However, the fabrication of IS-OECTs presents challenges due to the limited availability of OMIEC materials that possess the desired combination of mechanical and electrical properties. In this work, 1) we report the first successful fabrication of a vertical intrinsically stretchable OECT (VIS-OECT), achieved by using elastoadhesive electrodes; 2) we experimentally proved that vertical architecture can push the strain limit of an IS-OECT from 20% to 50%; and 3) the above finding introduces an unconventional design concept: the strain limit of an IS-OECT can surpass the intrinsic stretchability of the constituent OMIECs by employing vertical structure.