This work presents a proposed mechanism for fabricating Y-shaped nanorods, demonstrates the feasibility of the proposal through classical molecular dynamics simulations, and validates the simulations through magnetron sputter deposition experiments. The proposed mechanism relies primarily on the formation of stacking faults during deposition and to a lesser degree on diffusion kinetics and geometrical shadowing. Applications of the proposed mechanism may enable the design of nanorod arrays with controlled branching.

Arrays of Cr zigzag nanosprings and slanted nanorods, 15-55 nm and 40-80-nm-wide, respectively, were grown on SiO2/Si substrates by glancing angle deposition. The 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(-10) N per spring), which causes them to physically touch their neighbors, providing a path for electric current to flow between nanosprings. Repeated loading and unloading at large loads (> or =1 MPa) results in irreversible plastic deformation and a degradation of the pressure sensitivity.

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A macroscopic block ͑ϳ9 mm 3 ͒ of aligned carbon nanotubes ͑CNTs͒ was grown by chemical vapor deposition and its simultaneous electrical conductivity and compressive strain responses were measured parallel and perpendicular to the CNT alignment. The block exhibits elastic moduli of 0.9 and 1.6 MPa for compressive strain of Ͻ20% in parallel and perpendicular configurations, respectively. The electrical conductivity increases with increasing compressive strain in both configurations. The reversible electrical conductivity and compressive strain responses of block is attributed to elastic bending of CNTs. These excellent properties of CNT block can be used in compressive strain sensing applications.

Regular arrays of freestanding Cu nanostructures were grown on patterned Si substrates using glancing angle deposition ͑GLAD͒ from two oppositely positioned sputtering sources. Continuous azimuthal substrate rotation during deposition leads to the formation of vertical 430-nm-wide rods, which broaden anisotropically during subsequent growth with a stationary substrate. Statistical analyses of plan-view micrographs combined with numerical simulations indicate a linear increase in the width aspect ratio with deposition time that is attributed to a change in the growth front direction. This technique, termed simultaneous opposite GLAD, provides a unique approach for nanostructure shaping.