AVS 53rd International Symposium
    Advanced Surface Engineering Wednesday Sessions
       Session SE-WeM

Paper SE-WeM11
Nanospring Pressure Sensors and Branched Nanorods grown by Glancing Angle Deposition

Wednesday, November 15, 2006, 11:20 am, Room 2007

Session: Glancing Angle Deposition
Presenter: S.V. Kesapragada, Rensselaer Polytechnic Institute
Authors: S.V. Kesapragada, Rensselaer Polytechnic Institute
D. Gall, Rensselaer Polytechnic Institute
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Periodic arrays of Cr zigzag nanosprings and nanorods, 15-55 nm and 40-80 nm wide respectively, and Y-shaped Cu nanopillars were grown on patterned substrates by Glancing Angle Deposition (GLAD) in pure Ar discharges at 1 mTorr. Cr nanospring and nanorod arrays exhibit a reversible change in resistivity upon loading and unloading, by 50% for nanosprings and 5% for nanorods, indicating their potential as pressure sensors. The resistivity drop is due to a compression of nanosprings (by a measured 19% for an applied external force of 10@super -10@ N per spring), which causes them to physically touch their neighbors, providing a path for electric current to flow between nanosprings. We demonstrate a novel process for the formation of Y-shaped nanorods by exploiting the combination of atomic shadowing effects during GLAD and the spontaneous stacking fault formation in fcc metals. <110> oriented Cu nanorods self-organize into branched Y-structures due to stacking fault formation on two oppositely tilted 111-facets, followed by a growth suppression at the developing grain boundary. @FootnoteText@ @footnote 1@ S.V. Kesparagada, P. Victor, O. Nalamasu, and D. Gall, "Nanospring Pressure Sensors by Glancing Angle Deposition" Nano Lett. 6 [4] 854 (2006)@footnote 2@ J. Wang, H. Huang, S.V. Kesapragada, and D. Gall, "Growth of Y-shaped Nanorods by Physical Vapor Deposition" Nano Lett. 5 [12] 2505 (2005).