3D Printed Multifunctional Polymeric Nanocomposite Components With Sensing Capability

Conventional polymeric 3D printing offers efficient ways to produce 3D structures. To provide the functional capability of 3D structures, we have incorporated conductive additives such as multi-walled carbon nanotubes (MWCNTs) within the 3D printed structures by utilizing a pellet-based extrusion system. The inclusion of MWCNTs in the nanocomposites allows the creation of semiconductive structures that can detect force or strain due to piezoresistive properties. During the printing process, the shear forces can cause the MWCNTs to partially align, and this alignment is influenced by the chosen path scanning strategies. Our study aimed to determine how the alignment of MWCNTs affects the mechanical, electrical, and thermal properties of 3D-printed nanocomposite objects. We employed various characterization techniques including scanning electron microscopy (SEM), resistivity measurements, dynamic mechanical analysis (DMA), three-point bending, and cyclic bending tests at different raster angles (0°, 45°, and 90°) of 3D printed parts. A 3D Random Walk model was developed to simulate the influence of MWCNTs alignment on the piezoresistive behavior. The experimental results showed low electrical resistivity and high flexural strength in 3D printed samples, especially when printed in a longitudinal direction (0°). The highest sensing gauge factor was achieved when printing laterally (90°). To demonstrate the real-world applicability, we designed a self-sensing claw system for grippers with an integrated feedback mechanism using the 3D-printed nanocomposite. This study highlights the potential of pellet-fed polymeric nanocomposite 3D printing for generating semiconductive structures with sensing capabilities in diverse applications.