Nonlinear Feedback Controller of a Microbeam Resonator Hassen M. Ouakad 1 , Ali H. Nayfeh 2 , Slim Choura 3 , Eihab M. Abdel-Rahman 4 and Fehmi Najar 5 1 Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi-Arabia. 2 Department of Engineering Science and Mechanics, MC 0219, Virginia Tech, Blacksburg, VA 24061, USA. 3 Ecole Nationale d'Ingénieurs de Sfax, Mechanical Engineering Sfax, Sfax, Tunisia 4 Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada. 5 Applied Mechanics and Systems Research Laboratory, Tunisia Polytechnic School, University of Carthage, B.P. 743, La Marsa 2078, Tunisia. Corresponding author e-mail: anayfeh@vt.edu