Thermoelastic Damping in Nanomechanical Resonators with Finite Wave Speeds

Abstract

ABSTRACT The operation of micro-/nanobeams vibrating at very high frequencies, such as encountered in micro-/nanoelectromechanical systems (MEMS/NEMS), hinges on the minimization of intrinsic material losses. We study the associated thermoelastic damping in such beams from the standpoint of a generalized theory of thermoelasticity with one relaxation time. Some of our results relate to: (i) the cooling (instead of heating) in the compressed surface of the beam; (ii) the existence of not one damping peak appearing in the classical theory, but many peaks, with a decreasing amplitude as the frequency tends to infinity; (iii) the relevance of thermoelasticity with finite wave speeds for frequencies on the order of 1012 Hz. Keywords: Thermoelastic dampingGeneralized thermoelasticityNanoelectromechanical systems We benefited from discussions with Prof. S. Vengallatore. This work was made possible by the support of the Canada Research Chairs program and the funding from NSERC. Communicated by Józef Ignaczak on April 20, 2005.