3D PRINTED HIGHLY ELASTIC STRAIN SENSORS OF MULTIWALLED CARBON NANOTUBE/THERMOPLASTIC NANOCOMPOSITES

摘要

3D-printable, flexible, and electrically conductive thermoplastic-based material was successfully developed for strain sensing applications. Thermoplastic polyurethane/ multiwalled carbon nanotube (TPU/MWCNT) nanocomposites were compounded, their filaments fabricated, and sensor samples 3D printed using fused deposition modeling (FDM). Mechanical, electrical, and piezoresistivity behaviors for bulk and 3D printed TPU/MWCNT nanocomposites were investigated under monotonous and cyclic loadings. The results revealed very modest decreases in the printed nanocomposites moduli (~14.4%, compared to those of bulk counterparts), indicating excellent interlayer adhesion and performance. Electrical conductivity was largely preserved after printing and piezoresistivity gauge factors for the printed and bulk samples were found to be similar, indicating no decay in the printed samples under applied strains as large as 100%. Furthermore, a highly repeatable resistance-strain response was observed under cyclic loadings. The results demonstrate TPU/MWCNT nanocomposites as excellent piezoresistive feedstock for 3D printing.