Date of Award

12-2016

Degree Name

Master of Science in Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Dr. Muralidhar K. Ghantasala

Second Advisor

Dr. William W. Liou

Third Advisor

Dr. Pavel Ikonomov

Access Setting

Masters Thesis-Open Access

Abstract

Carbon Nanotubes (CNTs) have excellent mechanical, electrical and electromechanical properties. These properties led to a lot of novel applications. Due to change in electrical properties under mechanical loading, these composites have potential applications in strain sensors, when these are fabricated as films. CNT-based films are commonly fabricated using different physical and chemical techniques based on the property requirements governing those applications. In this work, CNT films were prepared using wet chemical based methods and chemical vapor deposition techniques.

Plasma chemical vapor deposition using microwave power is used in the first method to deposit films on silicon substrates, using Nickel film as a catalyst layer. The effect of different processing steps in this method, viz., hydrogen annealing, hydrogen plasma pre-growth treatment and MWCVD deposition properties on the film properties is studied in the first stage. In the second method, Carbon nanotube-polyurethane nanocomposite films of different loading proportions (1 to 8%) are prepared along with N-methyl-2-pyrrolidone (NMP) on different substrates using a spin coating. These film properties were analyzed using different characterization techniques.

These studies demonstrated the optimization of the growth and preprocess parameters with respect to the structural phase, microstructure and conductivity of these films in both the methods. Simulation of the CNT sensor characteristics was performed using COMSOL Multiphysics software. Optical lithography is used to fabricate the sensor structures using CNT nanocomposite films. The results of these studies were discussed in detail.

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