Abstract: A microscale collector and injector device comprises a microscale passive pre-concentrator (?PP) and a microscale progressively-heated injector (?PHI). The ?PP devices comprises first and second substrate portions, a first collection material, a ?PP heater, and an outlet. The first substrate portion defines an array of microscale diffusion channels. The first and second substrate portions cooperate to define a first compartment in fluid communication with the diffusion channels. The first collection material is disposed within the first compartment, at least partially surrounding the outlet. The ?PP heater is disposed in thermal communication with the second substrate portion. The ?PHI device comprises third and fourth substrate portions, a second collection material, and a plurality of ?PHI heaters. The third and fourth substrate portions cooperate to define a second compartment. The second collection material is disposed within the second compartment.

Abstract: A microscale collector and injector device comprises a microscale passive pre-concentrator (?PP) and a microscale progressively-heated injector (?PHI). The ?PP devices comprises first and second substrate portions, a first collection material, a ?PP heater, and an outlet. The first substrate portion defines an array of microscale diffusion channels. The first and second substrate portions cooperate to define a first compartment in fluid communication with the diffusion channels. The first collection material is disposed within the first compartment, at least partially surrounding the outlet. The ?PP heater is disposed in thermal communication with the second substrate portion. The ?PHI device comprises third and fourth substrate portions, a second collection material, and a plurality of ?PHI heaters. The third and fourth substrate portions cooperate to define a second compartment. The second collection material is disposed within the second compartment.

Abstract: A microscale collector and injector device comprises a microscale passive pre-concentrator (?PP) and a microscale progressively-heated injector (?PHI). The ?PP devices comprises first and second substrate portions, a first collection material, a ?PP heater, and an outlet. The first substrate portion defines an array of microscale diffusion channels. The first and second substrate portions cooperate to define a first compartment in fluid communication with the diffusion channels. The first collection material is disposed within the first compartment, at least partially surrounding the outlet. The ?PP heater is disposed in thermal communication with the second substrate portion. The ?PHI device comprises third and fourth substrate portions, a second collection material, and a plurality of ?PHI heaters. The third and fourth substrate portions cooperate to define a second compartment. The second collection material is disposed within the second compartment.

Abstract: A passive and reusable preconcentrator/injector device for measuring gas-phase analytes and methods of use. The device includes an upper plate defining an array of micro-scale diffusion channels and a lower plate secured to the upper plate. The lower plate defines a cavity for a reusable collection material in fluid communication with the micro-scale diffusion channels. An integral heating unit is provided adjacent the lower plate and configured for heating the cavity. A loading port may be included for introducing the reusable collection material into the cavity. An inlet port and an outlet port are provided, both in fluid communication with the cavity. The device may include a fluidic manifold system comprising a plurality of conduits disposed between the adsorbent cavity and the outlet port.

Abstract: A two-dimensional gas chromatography system having first and second separation columns, a thermal modulator disposed between the first and second columns and having a plurality of stage channels, and a micro heater monolithically integrated in the thermal modulator. The thermal modulator is operable to trap and focus gas/vapor species within the plurality of stage channels upon cooling and release the gas/vapor species to the second column upon heating by the micro heater.

Abstract: A two-dimensional gas chromatography system having first and second separation columns, a thermal modulator disposed between the first and second columns and having a plurality of stage channels, and a micro heater monolithically integrated in the thermal modulator. The thermal modulator is operable to trap and focus gas/vapor species within the plurality of stage channels upon cooling and release the gas/vapor species to the second column upon heating by the micro heater.

Abstract: A device for accumulation of vapor analytes incorporating nanotubes grown by CVD is described. The devices are used in sensors and as a preconcentrator for a gas chromatograph.

Abstract: A microelectromechanical heating apparatus and fluid preconcentrator device utilizing same wherein heating elements of the apparatus are sized and spaced to substantially uniformly heat a heating chamber within a heater of the apparatus. Tall, thermally-isolated heating elements are fabricated in Si using high aspect ratio etching technology. These tall heating elements have large surface area to provide large adsorbent capacity needed for high efficiency preconcentrators in a micro gas chromatography system (?GC). The tall heating elements are surrounded by air gaps to provide good thermal isolation, which is important for a low power preconcentrator in the ?GC system.

Abstract: A microelectromechanical heating apparatus and fluid preconcentrator device utilizing same wherein heating elements of the apparatus are sized and spaced to substantially uniformly heat a heating chamber within a heater of the apparatus. Tall, thermally-isolated heating elements are fabricated in Si using high aspect ratio etching technology. These tall heating elements have large surface area to provide large adsorbent capacity needed for high efficiency preconcentrators in a micro gas chromatography system (&mgr;GC). The tall heating elements are surrounded by air gaps to provide good thermal isolation, which is important for a low power preconcentrator in the &mgr;GC system.