Study of Thermally Induced Higher Order Microcantilever Modes

School of Graduate Studies The University of Alabama in Huntsville Degree Doctor of Philosophy Program Materials Science Program Name of Candidate Ashwini Kadam Title Study of Thermally Induced Higher Order Microcantilever Modes Microcantilevers have been widely studied for sensing tiny quantities of chemical and biological analytes in both vapor and liquid media. They have been shown to respond to changes in chemical, biological, thermal and physical processes. The primary sensing mechanisms are static bending due to induced differential surface stress and changes in the fundamental resonant frequency upon mass uptake. Although the possibility of using thermally induced higher order modes has been suggested for sensing and for understanding the mechanical behavior of microcantilevers, experimental demonstrations have not been given in the literature. Studies of thermally induced spectra provide an alternate in-situ detection technique for microcantilever sensing that is attractive in that no external excitation mechanism is required. However, thermally induced higher order modes have smaller amplitudes than what is obtained with external excitation. This dissertation examines the use of thermally induced higher order microcantilever modes both for sensing and studying adsorption induced interfacial changes between the Au coated microcantilever surface and Hg. The use of a thermally