Date of Award

Spring 1-1-2010

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical Engineering

First Advisor

Victor M. Bright

Second Advisor

Yung-Cheng Lee

Third Advisor

J. Scott Bunch

Abstract

In this work, microfabricated mechanical systems have been created in a variety of forms and operated to perform nanomaterials characterization tests. A simplified integrated test system was developed and used to collect data from a range of materials including gallium nitride nanowires. A new force estimation approach was developed which enables estimation of the forces provided by electrothermal microelectromechanical (MEMS) actuators, and with knowledge of a material specimen cross-section area, an estimation of the engineering stress within the nanomaterial specimen.

In an expanded design, a MEMS micromanipulator probe interfaced with a removable specimen holder, also known as a test coupon, to apply strain to and acquire tensile data from carbon nanotubes grown directly on a test coupon. A novel approach for removably interfacing two microfabricated chips was created. This interface mechanism enables the test coupon to incorporate a selection of possible experiments. These test devices can be operated in vacuum or air environments, and serve as a proof-of-concept of a microsystem testbed for mechanical measurements that can be performed simultaneously with other types of measurements such as electron diffraction, piezoresistive measurement, scanning tunneling microscope observation, or optical measurements.

The goal of this thesis was the demonstration of a microsystem capable of performing tensile characterization of nanowire or nanotube specimens that are not permanently interfaced to the actuators used to apply mechanical strain, with emphasis on the overall operation and characterization of this system.

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