Material Characterization of Carbon-Nanotube-Reinforced Polymer Composite

The material properties of Carbon-Nanotube (CNT) reinforced polymer composite are characterized by tensile testing to find the potential application of multi-walled carbon nano-tube (MWNT) to micro-devices and electronic packaging. SU-8 is used as a polymer material and mixed with MWNT of 0.2 wt%. Dogbone samples of 0.1 mm thickness are prepared by micro-fabrication process, which is composed of spin coat, soft bake, expose and post exposure bake. Young's modulus and Poisson's ratio are measured by changing applied strain rate at elevated temperatures. In this study, an in-house tensile testing setup called Nano Characterization System (NCS) was utilized for accurate force measurement of micro-scale specimen. Also, Digital Image Correlation (DIC), in-situ strain measurement technique, was used to measure accurate strain. The material properties of CNT-reinforced SU-8 are compared with those of SU-8 material. In addition, the viscoelastic material properties of SU-8 are measured by stress relaxation test and dynamic mechanical analysis.