Honeycomb Film Morphologies for High-Performance Stretchable Electrochemical Transistors

The realization of fully stretchable electronic materials is central to advancing new types of mechanically agile and skin-integrable optoelectronic device technologies. Here we demonstrate a materials design concept combining a porous organic semiconductor honeycomb film morphology with a biaxially pre-stretched platform that enables high-performance organic electrochemical transistors (OECTs) with charge transport stability up to 30-140% tensional strain, limited only by metal contact fatigue. The pre-stretched honeycomb channel semiconductor, donor-acceptor polymer DPP-g2T (DPP=diketopyrrolopyrrole, 2T=dithiophene), exhibits high ion uptake with ultra-stable electrochemical and mechanical properties, > 1500 redox cycles with 10000 stretching cycles under 30% strain. Highly reliable electrocardiogram recording cycles and synapse responses under varying strains, along with mechanical finite element analysis, underscore that the present stretchable OECT design strategy is suitable for diverse applications requiring stable signal output under deformation with low power dissipation and robustness to mechanical deformation.