The nanomechanical NOSE

We present a novel chemical sensor based on a microfabricated array of silicon cantilevers. Individual cantilevers are sensitized for the detection of analytes using metal coatings. Analyte molecules chemisorbing or physisorbing on the cantilever coating and chemical reactions produce a change in interfacial stress between analyte molecules and cantilever. This leads to a nanomechanical response of the cantilever, i.e. bending. The bending is read out using a time-multiplexed optical beam-deflection technique. From magnitude and temporal evolution of the bending, quantitative information on analyte species and concentration is derived. Here, we demonstrate the detection of ethene and water vapor with such a nanomechanical nose.