Enhanced Frictional Anisotropy and Wear Resistance via Bioinspired Hybrid Graphene Oxide -Titania Nanopatterned Surfaces

Abstract

In this work, a bio-inspired hybrid surface is developed by fabricating a glancing angle deposition (GLAD)-based titania nanopatterned surface, followed by coating with graphene oxide (GO) sheets. The nanotribological properties of both the hybrid and uncoated patterned surfaces have been characterized using lateral force microscopy. Direction-dependent friction anisotropy is observed in both cases, and the anisotropy is more pronounced on the hybrid surface. The surface also exhibits significantly enhanced wear resistance compared to the uncoated patterned surface due to the stress-shielding effect of the GO layer. Interestingly, the lateral force maps reveal a significant interaction between the scanning tip and individual nanorods beneath the GO layer, demonstrating how the buried titania nanopattern can tune the friction on the hybrid surface. Apart from friction, other quantitative nanomechanical characterizations of the system contribute to understanding the nanoscale tribological properties of the patterned surface. Altogether, the realization of the wear-resistant hybrid surface, its direction-dependent frictional response, and the interpretation of the results presented here define a robust methodology for controlling friction for engineering applications.