Microcantilevers: Sensing Chemical Interactions via Mechanical Motion

摘要

Micromechanical devices comprise emerging sensor platforms with straightforward sensing mechanisms. Molecular adsorption onto the sensing element, typically a cantilever, shifts its resonance frequency and changes its surface forces (surface stress). Adsorption onto the sensing element composed of two chemically different surfaces produces a differential stress between the two surfaces and induces bending. The analyte that induces the mechanical response may be physi- or chemisorbed onto the cantilever in a reversible or irreversible process. Devices that respond to chemical stimuli in this manner are more commonly referred to as microcantilever sensors.1-6 A compelling feature of microcantilever sensors is that they can be operated in air, vacuum, or liquid. The rapid growth in microcantilever-based sensor technology parallels advancements in micromachining methodologies and is in response to the need for more sensitive and selective detection of airborne and waterborne toxic and pathogenic substances.