Self-sensing array of microcantilevers for 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.

1 . A chemical analysis system, comprising:
 an array of microcantilever probes, wherein each microcantilever probe of the array is the same or different, or a combination thereof, and wherein the microcantilever probes of the array are physically arranged in rows, columns, or a combination of rows and columns; and   a plurality of drive and sense elements, wherein drive and sense elements of the plurality of drive and sense elements individually are coupled to microcantilever probes of the array.   
     
     
         2 . The chemical analysis system of  claim 1 , wherein the drive and sense elements of the plurality of drive and sense elements are unitary piezoelectric elements. 
     
     
         3 . The chemical analysis system of  claim 2 , wherein the drive and sense elements are electrically connected to one another in series, parallel, or a combination thereof. 
     
     
         4 . The chemical analysis system of  claim 1 , wherein at least one microcantilever probe of the array includes a resistive heater comprising a resistive heating element thermally coupled to the at least one microcantilever probe. 
     
     
         5 . The chemical analysis system of  claim 4 , wherein a plurality of resistive heaters are electrically connected in series, parallel, or individually to an electrical current source. 
     
     
         6 . The chemical analysis system of  claim 4 , wherein the resistive heater is configured to be heated to clean the at least one microcantilever probe. 
     
     
         7 . The chemical analysis system of  claim 4 , wherein the resistive heater is configured to be heated to cause a target chemical exposed to the at least one microcantilever probe to burn off, deflagrate, or otherwise chemically react on a surface of the at least one microcantilever probe. 
     
     
         8 . The chemical analysis system of  claim 1 , further comprising at least one reference microcantilever probe in the array, wherein the at least one reference microcantilever probe is uncoated, coated with an inert material, or protected from exposure to a target chemical species. 
     
     
         9 . The chemical analysis system of  claim 8 , wherein the at least one reference microcantilever probe is configured to correct responses from the array for effects of temperature, pressure, or viscosity. 
     
     
         10 . The chemical analysis system of  claim 8 , further comprising a controller configured to determine the target chemical species through one or more of pattern recognition techniques, statistical processes, or fuzzy logic by comparing a response from a microcantilever probe of the array to a reference set of microcantilever probe responses. 
     
     
         11 . The chemical analysis system of  claim 1 , wherein a drive and sense element of the plurality of drive and sense elements is configured to sense a shifted resonant frequency, a shifted quality factor, a shifted impedance, or a shifted deflection amplitude when a microcantilever probe to which the drive and sense element is coupled is exposed to a target chemical species. 
     
     
         12 . The chemical analysis system of  claim 1 , wherein one or more of the microcantilever probes comprises at least one chemical-sensitive coating material formulated and configured for chemical analysis and specificity. 
     
     
         13 . The chemical analysis system of  claim 1 , further comprising an interface circuit or a controller comprising a fast Fourier transform generator configured to perform a fast Fourier transform on a probe response from a microcantilever probe of the array to detect the target chemical species. 
     
     
         14 . The chemical analysis system of  claim 1 , further comprising a system enclosure including filters or scrubbers. 
     
     
         15 . The chemical analysis system of  claim 1 , further comprising a concentrator configured to concentrate a target chemical species proximal to the array. 
     
     
         16 . The chemical analysis system of  claim 1 , further comprising an adjustable frequency generator configured to drive each drive and sense element of the plurality of drive and sense elements by scanning through a predetermined frequency range to excite the microcantilever probes through the resonant frequency range of one or more of the microcantilever probes. 
     
     
         17 . The chemical analysis system of  claim 16 , wherein the scan through the predetermined frequency range is used to establish a baseline response of the array. 
     
     
         18 . The chemical analysis system of  claim 1 , wherein the array comprises up to one million microcantilever probes. 
     
     
         19 . The chemical analysis system of  claim 1 , further comprising a software application running on a computer or digital device, wherein the software application is used to analyze a response from microcantilever probes exposed to an analyte of interest and determine one or more components of the analyte of interest. 
     
     
         20 . A chemical analysis system, comprising:
 an array of microcantilever probes, wherein each microcantilever probe of the array is the same or different, or a combination thereof, and wherein the microcantilever probes of the array are physically arranged in rows, columns, or a combination of rows and columns;   a plurality of drive and sense elements, wherein drive and sense elements of the plurality of drive and sense elements individually are coupled to microcantilever probes of the array;   a plurality of resistive heating elements, wherein resistive heating elements of the plurality of resistive heating elements individually are coupled to microcantilever probes of the array; and   wherein the drive and sense elements are electrically connected to one another in series, parallel, or a combination thereof;   wherein the resistive heating elements are electrically connected in series, parallel, or individually.   
     
     
         21 . The chemical analysis system of  claim 20 , wherein one or more resistive heater elements are configured to be heated to clean at least one microcantilever probe of the array. 
     
     
         22 . The chemical analysis system of  claim 20 , wherein one or more resistive heater elements are configured to be heated to cause a target chemical exposed to at least one microcantilever probe of the array to burn off, deflagrate, or otherwise chemically react on a surface of the at least one microcantilever probe. 
     
     
         23 . The chemical analysis system of  claim 20 , further comprising at least one reference microcantilever probe in the array, the at least one reference microcantilever probe being uncoated, coated with an inert material, or otherwise protected from exposure to a target chemical species. 
     
     
         24 . The chemical analysis system of  claim 23 , wherein the at least one reference microcantilever probe is configured to correct responses from the array for effects of temperature, pressure, or viscosity. 
     
     
         25 . The chemical analysis system of  claim 20 , wherein drive and sense elements of the plurality of drive and sense elements are configured to sense a shifted resonant frequency, a shifted quality factor, a shifted impedance, or a shifted deflection amplitude when at least one microcantilever probe is exposed to a target chemical species. 
     
     
         26 . The chemical analysis system of  claim 20 , further comprising at least one chemical sensitive coating material on one or more microcantilever probes of the array, wherein the chemical sensitive coating material is formulated and configured for chemical analysis and specificity. 
     
     
         27 . The chemical analysis system of  claim 20 , further comprising an interface circuit or a controller comprising a fast Fourier transform generator configured to perform a fast Fourier transform on a response from one or more microcantilever probes of the array to detect a target chemical species. 
     
     
         28 . The chemical analysis system of  claim 20 , further comprising a system enclosure includes filters or scrubbers. 
     
     
         29 . The chemical analysis system of  claim 20 , further comprising a concentrator configured to concentrate a target chemical species proximal to the array. 
     
     
         30 . The chemical analysis system of  claim 20 , further comprising an adjustable frequency generator configured to drive each drive and sense element of the plurality of drive and sense elements by scanning through a predetermined frequency range to excite the microcantilever probes through the resonant frequency range of one or more of the microcantilever probes. 
     
     
         31 . The chemical analysis system of  claim 20 , wherein the microcantilever probes of the array of microcantilever probes are connected to a pair of drive pads. 
     
     
         32 . The chemical analysis system of  claim 20 , further comprising electrodes above and below each drive and sense element of the plurality of drive and sense elements, wherein the electrodes of one drive and sense element are connected in parallel with electrodes of another drive and sense element. 
     
     
         33 . The chemical analysis system of  claim 20 , further comprising a species attraction electrode underneath or adjacent to a chemical-sensitive coating material on at least one microcantilever probe of the array. 
     
     
         34 . The chemical analysis system of  claim 20 , wherein the array of microcantilever probes comprises at least a first group of microcantilever probes connected in series or in parallel to drive pads electrically coupled to at least another group of microcantilever probes. 
     
     
         35 . A chemical analysis system, comprising:
 an array of microcantilever probes, wherein the microcantilever probes are arranged in rows, columns, or a combination of rows and columns and wherein the array comprises at least a first group of microcantilever probes and a second group of microcantilever probes; and   a plurality of piezoelectric drive and sense elements each comprising a piezoelectric material, wherein piezoelectric drive and sense elements individually are associated with microcantilever probes of the array;   wherein the first group of microcantilever probes comprises a network of series-connected and parallel-connected microcantilever probes electrically connected to a pair of drive pads and the second group of microcantilever probes comprises another network of series-connected and parallel-connected microcantilever probes electrically connected to another pair of drive pads.