Chemical sensor with oscillating cantilevered probe

Abstract

The invention provides a method of detecting a chemical species with an oscillating cantilevered probe. A cantilevered beam is driven into oscillation with a drive mechanism coupled to the cantilevered beam. A free end of the oscillating cantilevered beam is tapped against a mechanical stop coupled to a base end of the cantilevered beam. An amplitude of the oscillating cantilevered beam is measured with a sense mechanism coupled to the cantilevered beam. A treated portion of the cantilevered beam is exposed to the chemical species, wherein the cantilevered beam bends when exposed to the chemical species. A second amplitude of the oscillating cantilevered beam is measured, and the chemical species is determined based on the measured amplitudes.

1 . A system for sensing a chemical species, comprising:
 an array of cantilevered beams, at least a first cantilevered beam comprising a treated portion;   each cantilevered beam comprising a piezoelectric drive mechanism and a piezoelectric sense mechanism;   wherein the first cantilevered beam is driven into oscillation, and the chemical species is determined based on changes measured by the sense mechanism of the first cantilevered beam when the treated portion of the first cantilevered beam is exposed to the chemical species.