Abstract: Highly sensitive sensor platforms for the detection of specific reagents, such as chromate, gasoline and biological species, using microcantilevers and other microelectromechanical systems (MEMS) whose surfaces have been modified with photochemically attached organic monolayers, such as self-assembled monolayers (SAM), or gold-thiol surface linkage are taught. The microcantilever sensors use photochemical hydrosilylation to modify silicon surfaces and gold-thiol chemistry to modify metallic surfaces thereby enabling individual microcantilevers in multicantilever array chips to be modified separately. Terminal vinyl substituted hydrocarbons with a variety of molecular recognition sites can be attached to the surface of silicon via the photochemical hydrosilylation process.

Abstract: Methods for the preparation of a stable, self-assembled monolayer on the silicon surface or metallic coating of a microcantilever are disclosed. The methods produce a microcantilever suitable as a chemical sensor. In a microcantilever produced using one version of the method, a metallic coating is disposed on a side of the microcantilever, a bridging atom is bonded to the metallic coating, a first spacer group is bonded to the bridging atom, a second spacer group is bonded to the bridging atom, and a chemical recognition agent is bonded to the first spacer group. In another version of the method, a silicon surface of a microcantilever is hydrogen terminated, and a calixarene chemical recognition agent is carbon linked to the silicon surface using photochemical hydrosilylation. Among other things, the calixarene may be bonded to a crown ether for ion detection or bonded to a area for the recognition of explosives by hydrogen bonding to nitro groups.

Abstract: Highly sensitive sensor platforms for the detection of specific reagents, such as chromate, gasoline and biological species, using microcantilevers and other microelectromechanical systems (MEMS) whose surfaces have been modified with photochemically attached organic monolayers, such as self-assembled monolayers (SAM), or gold-thiol surface linkage are taught. The microcantilever sensors use photochemical hydrosilylation to modify silicon surfaces and gold-thiol chemistry to modify metallic surfaces thereby enabling individual microcantilevers in multicantilever array chips to be modified separately. Terminal vinyl substituted hydrocarbons with a variety of molecular recognition sites can be attached to the surface of silicon via the photochemical hydrosilylation process.

Abstract: A chemically functionalized cantilever system has a cantilever coated on one side thereof with a reagent or biological species which binds to an analyte. The system is of particular value when the analyte is a toxic chemical biological warfare agent or an explosive.

Abstract: A chemically functionalized cantilever system has a cantilever coated on one side thereof with a reagent or biological species which binds to an analyte. The system is of particular value when the analyte is a toxic chemical biological warfare agent or an explosive.

Abstract: Highly sensitive sensor platforms for the detection of specific reagents, such as chromate, gasoline and biological species, using microcantilevers and other microelectromechanical systems (MEMS) whose surfaces have been modified with photochemically attached organic monolayers, such as self-assembled monolayers (SAM), or gold-thiol surface linkage are taught. The microcantilever sensors use photochemical hydrosilylation to modify silicon surfaces and gold-thiol chemistry to modify metallic surfaces thereby enabling individual microcantilevers in multicantilever array chips to be modified separately. Terminal vinyl substituted hydrocarbons with a variety of molecular recognition sites can be attached to the surface of silicon via the photochemical hydrosilylation process.

Abstract: A two-track piezoresistive cantilever detects explosives in ambient air by measuring resistance changes in the cantilever when one piezoresistive track is pulse heated to cause deflagration of explosive adhered to the surface of the cantilever. The resistance measurement is through the second piezoresistive track, which is located at the most resistance-sensitive area. The resistance change of this track is caused by the temperature change of the cantilever as well as the bending of the cantilever due to bi-material thermal expansion. The detecting method using this novel cantilever avoids the use of any optical components such as a laser and position sensing detector (PSD), which are necessary in traditional detecting systems using cantilevers. Therefore, it can extremely reduce the complexity of the detecting system and make a portable chemical detection system possible that is small, less expensive, and able to be mass produced and is particularly useful for the detection of explosives.

Abstract: An instrument for analyzing a sample has an enclosure that forms a chamber containing an anode which divides the chamber into a discharge region and an analysis region. A gas inlet and outlet are provided to introduce and exhaust a rare gas into the discharge region. A cathode within the discharge region has a plurality of pins projecting in a geometric pattern toward the anode for exciting the gas and producing a plasma discharge between the cathode and the anode. Low energy electrons (e.g. <0.5 eV) pass into the analysis region through an aperture. The sample to be analyzed is placed into the analysis region and bombarded by the metastable rare gas atoms and the low energy electrons extracted into from the discharge region. A mass or optical spectrometer can be coupled to a port of the analysis region to analyze the resulting ions and light emission.

Abstract: A gas laser includes an enclosure forming a first chamber, a second chamber and a lasing chamber which communicates through a first opening to the first chamber and through a second opening to the second chamber. The lasing chamber has a pair of reflectors defining a Fabry-Perot cavity. Separate inlets enable different gases to be introduced into the first and second chambers. A first cathode within the first chamber is provided to produce positive ions which travel into the lasing chamber and a second cathode of a pin-hollow type within the second chamber is provided to produce negative ions which travel into the lasing chamber. A third inlet introduces a molecular gas into the lasing chamber, where the molecular gas becomes excited by the positive and negative ions and emits light which lases in the Fabry-Perot cavity.