3D printing of ultra-tough, self-healing transparent conductive elastomeric sensors

Abstract Ultra-tough transparent conductive elastomers (TCEs) with self-healing performance are of great significance for research in the fields of soft robotics, optical display electronics, wearable electronic equipment and human–computer interaction. However, their limitation, such as the desolventizing process, low polymerization rate or balance between toughness and self-healing performance, cause difficulty in manufacturing by the 3D printing technique. Here, we propose a novel preparation strategy for 3D printed TCEs based on the photopolymerization of maleic acid (MA)/choline chloride (ChCl) and acrylamide (AAm)/choline chloride type polymerizable deep eutectic solvents (PDESs). PDES can polymerize into a tough and rich in hydrogen bonds poly(PDES) in a few seconds without solvent evaporation. The printed TCEs with precision of 10 µm have high transparency (95.6%) and stable electrical signals at 50% compression for 10,000 cycles. In addition, efficient self-healing performance due to the dynamic hydrogen bonds of poly(PDES) provides broad application prospects for 3D printed TCEs in long-term pressure-resistant intelligent applications.