MAGNETIC ALIGNMENT OF TiO2 NANOTUBES
Casey S. Mungle and Steve Semancik
A novel method for magnetically aligning TiO2 nanotubes into preferred orientations is being investigated as a potential methodology for fabricating improved chemical sensors. Metal oxide nanotubes have shown potential as highly sensitive chemical detectors due to their inherent material properties and structural scale. The TiO2 nanotubes are produced via template-assisted sol-gel methods, and Ni nanowires are electrodeposited inside the nanotubes, before dissolution of the alumina template, to provide a ferromagnetic core. Related techniques have been reported in the literature for fabrication of high-density data storage and similar devices. However, we intend to use the magnetic core as a sacrificial layer to assemble ordered arrays of nanotubes. After removal of the template and dispersion of the nanotubes in solution, externally applied magnetic fields may be employed to manipulate these nanotube/nanowire structures. A gradient in the magnetic field strength directs the nanotubes towards a substrate surface while the direction of the magnetic field aligns the nanotubes in parallel orientation. Once in the desired orientation the Ni nanowires may be etched out using chemical processes. This magnetic alignment technique will enable the fabrication of model assemblies that will be used to investigate how the scale and orientation of nanotube arrays affects their sensing characteristics.
Casey S. Mungle
Mentor: Steve Semancik
Process Measurements Division (836)
A303, Bldg. 221
Sigma Xi: No