study of the origin of bending induced by bimetallic effect on microcantilever研究的起源对微悬臂弯曲双金属引起的影响.pdf

Sensors 2007, 7, 1757-1765 sensors ISSN 1424-8220 © 2007 by MDPI /sensors Communication Study of the Origin of Bending Induced by Bimetallic Effect on Microcantilever Daniel Ramos, Johann Mertens, Montserrat Calleja and Javier Tamayo* BioNanoMechanics Lab, National Centre for Microelectronics, IMM-CNM, CSIC Isaac Newton 8 (PTM), Tres Cantos 28760, Madrid, Spain * Author to whom correspondence should be addressed. jtamayo@m.csic.es Received: 30 July 2007 / Accepted: 4 September 2007 / Published: 5 September 2007 Abstract: An analytical model for predicting the deflection and force of a bimaterial cantilever is presented. We introduce the clamping effect characterised by an axial load upon temperature changes. This new approach predicts a non linear thermal dependence of cantilever strain. A profilometry technique was used to measure the thermal strain. Comparison with experimental results is used to verify the model. The concordance of the analytical model presented with experimental measurements is better than 10%.. Keywords: cantilever, stress, strain, temperature, Stoney’s equation, axial force, profile. 1. Introduction Atomic force microscope (AFM) cantilevers are known to be very sensitive to temperature [1]. Bimaterial microcantilevers have been used for a large number of applications that take advantage of this thermal sensitivity, as well as the reduction in the size of the probe and the high parallelizability, that impro