Compressive response of vertically aligned carbon nanotube films gleaned from in situ flat-punch indentations
Abstract
We report the mechanical behavior of vertically aligned carbon nanotube films, grown on Si substrates using atmospheric pressure chemical vapor deposition, subjected to in situ large displacement (up to 70 μm) flat-punch indentations. We observed three distinct regimes in their indentation stress–strain curves: (i) a short elastic regime, followed by (ii) a sudden instability, which resulted in a substantial rapid displacement burst manifested by an instantaneous vertical shearing of the material directly underneath the indenter tip by as much as 30 μm, and (iii) a positively sloped plateau for displacements between 10 and 70 μm. In situ nanomechanical indentation experiments revealed that the shear strain was accommodated by an array of coiled carbon nanotube "microrollers," providing a low-friction path for the vertical displacement. Mechanical response and concurrent deformation morphologies are discussed in the foam-like deformation framework with a particular emphasis on boundary conditions.
Additional Information
© 2012 Materials Research Society. Received 31 March 2012; accepted 28 September 2012. Published online: 27 November 2012. The authors acknowledge S. Hutchens and A. Needleman for helpful insights and guidance, E. Lim for data analysis, financial support from the Georgia Institute of Technology Foundation through the Joseph Anderer Faculty Fellowship, and the Institute for Collaborative Biotechnologies (ICB) for financial support through Grant No. W911NF-09-0001 from the U.S. Army Research Office. The content of the information does not necessarily reflect the position or the policy of the Government, and no official endorsement should be inferred. S.P. gratefully acknowledges support from the W.M. Keck Institute for Space Studies Postdoctoral Fellowship program for this work. We gratefully acknowledge critical support and infrastructure provided for this work by the Kavli Nanoscience Institute at Caltech.Attached Files
Published - S0884291412003664a.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:3d242b77cc619a44b7886aef2e758361
|
992.3 kB | Preview Download |
Additional details
- Eprint ID
- 38317
- Resolver ID
- CaltechAUTHORS:20130507-103249946
- Georgia Institute of Technology Foundation Joseph Anderer Faculty Fellowship
- W911NF-09-0001
- Army Research Office (ARO)
- Keck Institute for Space Studies (KISS)
- Created
-
2013-05-07Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Keck Institute for Space Studies