Mechanical and Strain-Sensing Capabilities of Carbon Nanotube Reinforced Composites by Digital Light Processing 3D Printing Technology

Abstract

Mechanical and strain sensing capabilities of carbon nanotube (CNT) reinforced composites manufactured by digital light processing (DLP) 3D printing technology have been studied. Both CNT content and a post-curing treatment effects have been analyzed. It has been observed that post-curing treatment has a significant influence on mechanical properties, with an increase of Young’s modulus and glass transition temperature whereas their effect in electrical properties is not so important. Furthermore, the strain sensing tests show a linear response of electrical resistance with applied strain, with higher values of sensitivity when decreasing CNT content due to a higher interparticle distance. Moreover, the electrical sensitivity of bending tests is significantly lower than in tensile ones due to the compression subjected face effect. Therefore, the good gauge factor values (around 2–3) and the high linear response proves the applicability of the proposed nanocomposites in structural health monitoring applications.

Complex Geometry Strain Sensors Based on 3D Printed Nanocomposites: Spring, Three-Column Device and Footstep-Sensing Platform

“…It is widely known that, for the calendering process, a higher viscosity of the mixture allows for obtaining a better dispersion since the shear forces applied to the CNT aggregates are more effective [ 31 , 32 ]. On the other hand, in the case of MWCNT mixtures, which are already well dispersed even for the lowest content, an increase in the CNT content slightly increases the aggregate size [ 24 ].…”

“…These sensing devices are based on nanocomposites doped with three different types of CNTs (SWCNTs, DWCNTs and MWCNTs) and manufactured by digital light processing (DLP) 3D printing technology. In this regard, the present paper is a follow-up of previous work conducted with MWCNT-doped nanocomposites [ 24 ] to study how the addition of different CNT types (DWCNT and SWCNT) affect electrical and electromechanical properties and the strong relation of these properties to the dispersion state of the nanoparticles into the matrix.…”

Highly Flexible and Photo-Activating Acryl-Polyurethane for 3D Steric Architectures

“…Photo-curing 3D printing based on the digital light processing (DLP) technique has been used consistently to produce complex architectures without the need for additional tools and machines [ 1 , 2 ]. DLP printing is an advanced technology involved in the light-mediated conversion of a monomer or oligomer resin to a solid photopolymer object [ 3 , 4 , 5 , 6 , 7 , 8 ]. UV-curable resins are suitable for the manufacture of complex and high-precision 3D objects in many fields.…”

Carbon Nanotube Reinforced Poly(ε-caprolactone)/Epoxy Blends for Superior Mechanical and Self-Sensing Performance in Multiscale Glass Fiber Composites

“…Therefore, the addition of CNTs gives the composite new and interesting multifunctionalities. More specifically, the composite shows excellent piezoresistive behavior that, in conjunction with the tunneling transport that occurs between adjacent nanoparticles, makes possible the strain and damage monitoring by means of electrical conductivity measurements [ 13 , 14 , 15 , 16 , 17 ]. This capability has been extensively explored in multiscale GF composites [ 18 ], showing a particularly high sensitivity to interlaminar [ 19 ], impact failure [ 20 ], or moisture damage propagation [ 21 ], as well as good flow and cure monitoring capabilities [ 22 , 23 ], making the multiscale composites suitable for structural health monitoring (SHM) applications.…”