Thermal and mechanical phenomena in aligned carbon nanotube films
Abstract/Contents
- Abstract
- Efficient heat conduction is critical to the performance and reliability of a variety of devices. To ensure efficient heat removal from electronic devices, thermal interface materials (TIMs) are used to enhance heat conduction between two contacting surfaces. Ideal TIMs have high thermal conductivity, conform to the microscale roughness of the surfaces in contact, and accommodate stresses due to mismatch in thermal expansion coefficients. Commercial TIMs exhibit a tradeoff between these desired thermal and mechanical properties. Vertically aligned carbon nanotube (VACNT) films have great promise as TIMs because they have high through-plane thermal conductance and mechanical compliance. VACNT films are typically composed of a complex, entangled network of CNTs and the density and alignment of CNTs within a film affect its mechanical and thermal properties. Given the variety of growth techniques and variations in film morphology, it is important to understand how these factors influence film behavior. The present work combines three major aspects of VACNT film characterization: mechanical and thermal characterization, analysis of the film microstructure, and modeling of the film properties. The inhomogeneous VACNT film morphology is investigated by using image analysis to quantify CNT alignment and density and by measuring the elastic modulus at the top and bottom film surfaces using nanoindentation. The alignment and density information is input into a model of the mechanical response of the VACNT film, which is compared to measured data. The through-plane thermal properties of VACNT films are measured using thermoreflectance techniques. Multiwall VACNT films are grown directly on a thermoelectric material and the thermal properties of the films are characterized using nanosecond thermoreflectance. A set of eight single-wall VACNT films are measured using frequency domain thermoreflectance to extract four relevant thermal properties: thermal conductivity, heat capacity, and the upper and lower boundary resistances.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Gao, Yuan |
|---|---|
| Associated with | Stanford University, Department of Mechanical Engineering |
| Primary advisor | Goodson, Kenneth E, 1967- |
| Thesis advisor | Goodson, Kenneth E, 1967- |
| Thesis advisor | Cai, Wei |
| Thesis advisor | Kenny, Thomas William |
| Advisor | Cai, Wei |
| Advisor | Kenny, Thomas William |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Yuan Gao. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2012. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Yuan Gao
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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