Lipoic acid-derived high-performance polythiourethane elastomers for flexible electronic devices

Bio-based polythiourethanes are attractive candidates for sustainable soft electronics, but the pronounced plasticity and insufficient dimensional stability of lipoic acid-derived networks limit their practical use. Here, a lipoic acid-derived polythiourethane elastomer (FLPU) is constructed by integrating thermally reversible Diels-Alder (DA) crosslinks with dynamic thiourethane chemistry. The resulting covalent adaptable network combines high tensile strength (15.12 ± 2.42 MPa), large elongation at break (∼800%), efficient stress relaxation, and self-healing efficiency above 95% after healing at 60 °C for 36 h, while retaining optical transparency, reprocessability, and excellent cytocompatibility. Direct ink writing of a photopolymerizable ionic-liquid ink on FLPU enables rapid room-temperature fabrication of stretchable conductive patterns with strong interfacial adhesion, matched mechanical compliance, and stable ionic conduction. The printed devices tolerate large deformation and long-term cyclic loading with negligible signal drift, providing a sustainable route to mechanically robust, recyclable, and wearable polymer electronics.