( ( Microtribology ( using ( Friction ( Force Microscope ) ) ) ) . )
(ROOT (S (VP (ADVP (RB Microtribology)) (VBG using) (NP (NNP Friction) (NNP Force) (NNP Microscope))) (. .)))
Microtribology using Friction Force Microscope.
(ROOT (S (NP (NN Friction) (NN force)) (VP (VBZ is) (VP (VBN caused) (PP (IN by) (NP (NP (JJ microscopic) (NNS bumps)) (, ,) (VP (VBZ lumps)) (, ,) (CC and) (NP (NP (NNS imperfections)) (VP (VBG colliding))))))) (. .)))