1 The morphology of TiO 2 nanotube arrays grown from atomically peened and non-atomically peened Ti films Samira Farsinezhad 1 , Arash Mohammadpour 1 , Mourad Benlamri 1 , Ashley N. Dalrymple 1 and Karthik Shankar 1,2* 1 Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada 2 National Institute for Nanotechnology, National Research Council, 11421 Saskatchewan Drive, Edmonton, AB, T6G 2M9, Canada *Author to whom correspondence should be addressed. Email: kshankar@ualberta.ca Submitted: May 24, 2016 Accepted: Jun 16, 2016 ABSTRACT The growth of TiO 2 nanotube arrays (TNTAs) on non-native substrates is essential for exploiting the full potential of this nanoarchitecture in applications such as gas sensing, biosensing, anti- fouling coatings, low-cost solar cells, drug-eluting bimedical implants and stem-cell differentiators. The direct formation of anodic TNTAs on non-native substrates requires the vacuum deposition of a thin film of titanium on the substrate followed by subsequent electrochemical anodization of the film. In this report, we studied the effect of atomic peening on the formation of Ti thin films on technologically important non-native substrates. We compared