An implantable medical device includes a lead body having a distal end and a proximal end, a lumen and at least one lead wire extending through the lumen. The lead wire has an outer surface and a polymeric coating on at least a portion of the outer surface of the lead wire. The coating includes a first structure having a first end proximate the outer surface of the lead wire and a second end opposite the first end. The second end is movable relative to the first end and relative to the lead wire.