Mechanical Characteristics of FIB Deposited Carbon Nanowires Using an Electrostatic Actuated Nano Tensile Testing Device

Abstract

This research is directed at the development of Electrostatic Actuated NAno Tensile testing devices (EANATs) for measuring mechanical properties of carbon nanowires, deposited by focused ion beam-assisted chemical vapor deposition (FIB-CVD) using phenanthrene gas. The EANATs were composed of the specimen part, actuator part and measurement part. 1000, 3000 and 5000 pairs of comb drive actuators were prepared within the actuator part for stretching the nanowires. The measurement part had a cantilever used as a lever motion amplification system for measuring tensile displacement of the nanowires. A theoretical resolution of 0.17 nm in tensile displacement was achieved using the amplification system and imaging analysis. The uniaxial tensile force was derived from the total spring constant of suspended beams built within the EANATs, with the theoretical resolutions ranging from 108 to 113 nN. This research was therefore successful in obtaining accurate load-displacement curves for carbon nanowires. The Young's modulus observed for the nanowires provided the scatter in absolute values ranging from 42.6 to 80.7 GPa. The fracture stress and strain of the nanowires exhibited larger values of 4.3 GPa and 0.08 strain, respectively. Discussion of the deformation behaviors and failure mechanisms of the nanowires is made from FE-SEM observations of the nanowires before and after tensile failure