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To cite this version:Sébastien Tétin, Benjamin Caillard, Francis Ménil, Hélène Debéda, Claude Lucat, et al.. Modeling and performance of uncoated microcantilever-based chemical sensors. Sensors and Actuators B: Chemical, Elsevier, 2010, 143, pp. AbstractChemical sensors based on vibrating silicon microcantilevers without sensitive coating are investigated herein.The sensor signal is the relative variation of the microcantilever resonant frequency which depends on both the viscosity and the density of the fluid surrounding the microcantilever. This principle has been applied to the detection of binary gas mixtures. Experimental data for He/N 2 and CO 2 /N 2 environments are presented and compared to results of theoretical modeling. The advantages of such a gas sensor based on changes of physical properties are discussed (response time, sensitivity, selectivity, stability).

Abstract:The use of microcantilevers as (bio)chemical sensors usually involves the application of a chemically sensitive layer. The coated device operates either in a static bending regime or in a dynamic flexural mode. While some of these coated devices may be operated successfully in both the static and the dynamic modes, others may suffer from certain shortcomings depending on the type of coating, the medium of operation and the sensing application. Such shortcomings include lack of selectivity and reversibility of the sensitive coating and a reduced quality factor due to the surrounding medium. In particular, the performance of microcantilevers excited in their standard outof-plane dynamic mode drastically decreases in viscous liquid media. Moreover, the responses of coated cantilevers operating in the static bending mode are often difficult to interpret. To resolve these performance issues, the following emerging unconventional uses of microcantilevers are reviewed in this paper: (1) dynamic-mode operation without using a sensitive coating, (2) the use of in-plane vibration modes (both flexural and longitudinal) in liquid media, and (3) incorporation of viscoelastic effects in the coatings in the static mode of operation. The advantages and drawbacks of these atypical uses of microcantilevers for chemical sensing in gas and liquid environments are discussed.

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