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Cantilever-Based Resonant Gas Sensors With Integrated Recesses For Localized Sensing Layer Deposition, C. Carron, P. Getz, J. J. Su, D. S. Gottfried, Fabien Josse, Stephen M. Heinrich

Civil and Environmental Engineering Faculty Research and Publications

This work presents mass-sensitive hammerhead resonators with integrated recesses as a gas-phase chemical microsensor platform. Recesses are etched into the head region of the resonator to locally deposit chemically sensitive polymers by ink-jet printing. This permits the sensing films to be confined to areas that (a) are most effective in detecting mass loading and (b) are not strained during the in-plane vibrations of the resonator. As a result of the second point, even 5-μm thick polymer coatings on resonators with a 9-12 μm silicon thickness barely affect the Q-factor in air. This translates into higher frequency stability and ultimately higher …