3D wet-spinning printing of wearable flexible electronic sensors of polypyrrole@polyvinyl formate

• Printing ink of polyvinyl formate was wet-spinning and mold into 3D elastic architectures. • 3D PPy@PVFm was fabricated into wearable electronic sensors. • PPy@PVFm stably and sensitively recognized physical movements over a wide range. • High DE led to shortening coagulation, improving hydrophobicity, and extending flexibility. Polymer based 3D printings are generally generated from the melt fluids or gels instead of polymer solution. Inspired by continuous wet-spinning of polymer fiber, we explored a new polyvinyl formate (PVFm) printing ink which was directly coagulated by water and mold into designed 3D elastic architectures layer-by-layer. The degree of esterification ( DE ), chemical structure, morphology, and mechanical properties of PVFm were all investigated. Furthermore, 3D PVFm was coated by polypyrrole (PPy) via in-situ polymerization to fabricate wearable flexible electronic sensors. The relative resistance changes and sensitivity of PPy@PVFm on monitoring physical strain and pressure were characterized. Results show that PPy@PVFm could stably and sensitively recognize human body activities through relative changes in resistance in a wide range of linear relationship. Therefore, a new protocol is readily to realize a strategy of 3D wet-spinning printing and wearable flexible electronic sensors.