Mechanical Sensors and Systems

We have been developing cantilever-based sensors for physical, chemical, and biological detection. We have also developed cantilever arrays of selective detection of a given chemical in presence of interfering molecules. Molecular adsorption on cantilevers results in cantilever bending (provided the adsorption is confined to a single side of the cantilever). In addition the resonance frequency of the cantilever varies sensitively as a function of mass loading. The bending of the cantilever is directly related to changes in adsorption-induced changes in surface energy. Both mass information (resonance frequency) as well as energy (cantilever bending) can be measured simultaneously. The response from the array is analyzed using pattern recognition algorithms. Efforts are presently underway to design nano and microcantilever sensor systems with detection sensitivity down to parts-per-trillion.