Self-sensing array of microcantilevers chemical detection

Abstract

The invention provides a chemical detection system for detecting at least one target chemical species, including a self-sensed cantilevered probe array having a plurality of self-sensed cantilevered probes, at least one chemical-sensitive coating material applied to at least one cantilevered probe in the cantilevered probe array, and an interface circuit that is coupled to the cantilevered probe array. At least one cantilevered probe in the cantilevered probe array exhibits a shifted cantilevered probe response when the cantilevered probe array is exposed to the target chemical species and the interface circuit actuates the cantilevered probe. A handheld chemical detection system and a method of operation are also disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This utility application claims the priority benefit of, and hereby incorporates by reference in its entirety, the applicant's prior U.S. Provisional Application No. 60 / 512,504, filed Oct. 17, 2004.FIELD OF THE INVENTION[0002]This invention relates generally to chemical-sensing methods, and in particular, relates to a method and system for sensing specific chemicals and biological materials using an array of piezoelectrically driven cantilevered probes with selectively disposed chemical sensitive coatings.BACKGROUND OF THE INVENTION[0003]Micromachined cantilevers are used in atomic force microscopy (AFM) for surface scanning and for chemical, biological, and other sensing applications. Micromachined cantilevers may become the basis for specialized, ultraminiature, ultrasensitive sensors for detection of specific target chemical species such as chemical compounds, bioactive agents, or toxins. Miniaturized chemical sensors hold promise for ...

AI Technical Summary

Benefits of technology

The system achieves compactness, reduced power consumption, and efficient chemical detection with minimal heat generation, enabling rapid detection of minute chemical concentrations and biomaterials in various environments.

Problems solved by technology

Lasers can be used for optical detection of cantilever movement, though AFM systems using lasers require comparably high power on the order of milliwatts, need alignment, have limited resolution, and are prone to drift because of the size of the optical path.

Current systems typically require external lighting for sample illumination and setup, and are not very compact because of the long optical path, the need to have the photodetector at an ample distance from the sample, and constrained viewing and positioning systems for optical alignment.

Sample testing in liquids such as water or saline solution presents additional difficulties for optical sensing due to aberrations and refraction of the light beam traversing the fluid.

Other limitations of capacitive schemes include small tolerances for fabrication and coatings of a cantilever, a reliance on a small sensing gap size, and difficulties with sensing in liquid solutions.

Piezoresistive sense methods are more compact than optical systems, though they can self-heat and cause drift.

Furthermore, piezoresistive sensing typically consumes large portions of available power when used in a portable device.

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