Polymer brushes consisting of end-grafted polymers on surfaces are frequently used to develop smart or responsive surfaces including biocompatible surfaces for retarding the non-specific adsorption of macromolecules, nanodevices, and self-biolubricating surfaces. We are interested in using atom transfer radical polymerization (ATRP) for examining the various parameters to control the density of the initiator grafted on silica surfaces and mica surfaces. Controlled polymerization will afford polymer brushes of consistent lengths that can easily be hydrolyzed affording charged brushes. The effect of different cations on the mechanical properties of the surfaces will be examined. In collaboration with Prof. S. Giasson, we are investigating covalent grafting of ATRP initiators and the controlled polymerization on activated mica to afford polymers with discrete molecular weights. Mica is the choice substrate for measuring mechanical properties by Surface Forces Apparatus (SFA). Because of the challenges to characterize the grafted materials to mica, we have developed new methods allowing to measure the absolute height of the brushes. Polymer brushes of controlled/known lengths are desired to examine the effect of different cations of the surface friction between two polymer surfaces measured by SFA. Various other techniques including AFM and ellipsometry are also used to characterize the brushes polymerized from the surface.