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.

Self-sensing array of microcantilevers for chemical detection

The invention provides a liquid cell for an atomic force microscope. The liquid cell includes a liquid cell housing with an internal cavity to contain a fluid, a plurality of conductive feedthroughs traversing the liquid cell housing between the internal cavity and a dry side of the liquid cell, a cantilevered probe coupled to the liquid cell housing, and a piezoelectric drive element disposed on the cantilevered probe. The cantilevered probe is actuated when a drive voltage is applied to the piezoelectric drive element through at least one of the conductive feedthroughs. A method of imaging an object in a liquid medium and a method of sensing a target species with the liquid cell are also disclosed.

Liquid cell and passivated probe for atomic force microscopy and chemical sensing

A disclosed chemical detection system for detecting a target material, such as an explosive material, can include a cantilevered probe, a probe heater coupled to the cantilevered probe, and a piezoelectric element disposed on the cantilevered probe. The piezoelectric element can be configured as a detector and/or an actuator. Detection can include, for example, detecting a movement of the cantilevered probe or a property of the cantilevered probe. The movement or a change in the property of the cantilevered probe can occur, for example, by adsorption of the target material, desorption of the target material, reaction of the target material and/or phase change of the target material. Examples of detectable movements and properties include temperature shifts, impedance shifts, and resonant frequency shifts of the cantilevered probe. The overall chemical detection system can be incorporated, for example, into a handheld explosive material detection system.

Cantilevered probe detector with piezoelectric element

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.

Chemical sensor with oscillating cantilevered probe and mechanical stop

Cantilevered probes having piezoelectric layer, treated section, and resistive heater, and method of use for chemical detection

The present invention relates to a micromechanical sensor (1) for detecting a target substante in a liquid or a gas and comprising at least one sensor unit with a capture surface (30) and at least one conducting element (2) of an electrically conducting material with a pair of wires for applying an electrical field over the conducting element. The conducting element comprises at least two divisional units (34) and the conducting element has a larger conductance in one sensor state than in another sensor state due to a change in contact area for electrical conduction between two or more divisional units on deformation from one sensor state to another in response to surface stress arising from a chemical interaction at the capture surface. The conducting element may preferably comprise 2-100 divisional units or even more which divisional units may be systemically arranged or randomly ordered e.g. in a non-conductive dispersant material. In a preferred embodiment, the sensor is used to detect DNA, and the conducting element (2) contains carbon nanowires.

Carsten Faltum

Papers

A sensor for use in detection of a target substance in a sample