Thomas J. Roussel

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We used a high-magnification shadow photogrammetric system to evaluate corneal buttons trephined from human donor globes. Whole eyes were trephined with one of five instruments: nonguarded blades held by hand or placed on a handle, Barraquer-Mateus motorized trephine, Hessberg-Barron suction trephine, or Hanna microkeratotrephine. Corneoscleral buttons were(More)
Microfabricated lab-on-a-chip devices employing a fully integrated electrochemical (EC) detection system have been developed and evaluated. Both capillary electrophoresis (CE) channels and all CE/EC electrodes were incorporated directly onto glass substrates via traditional microfabrication techniques, including photolithographic patterning, wet chemical(More)
Freely suspended microchannels with diameters ranging from 4 to 100 lm were fabricated by utilizing directly written PMMA fibers as sacrificial structures. These precisely oriented fibers served as scaffolds around which thin cylinders of glass were deposited (via sputtering), followed by a con-formal coating of Parylene to augment the mechanical integrity(More)
A scalable and rather inexpensive solution to producing microanalytical systems with "on-chip" three-dimensional (3D) microelectrodes is presented in this study, along with applicability to practical electrochemical (EC) detection scenarios such as preconcentration and interferant removal. This technique to create high-aspect-ratio (as much as 4:1) gold(More)
The diffusion mechanism of pure component Ar and binary mixtures of Ar/Kr and Ar/Ne confined in single-walled carbon nanotubes (SWNTs) and bundles was investigated by a combined Grand Canonical Monte Carlo and molecular dynamics study. For Ar confined in SWNTs, a crossover from single-file to Fickian diffusion existed when the density of Ar was a minimum as(More)
Miniaturized, battery-powered, high-voltage power supply, electrochemical (EC) detection, and interface circuits designed for microchip capillary electrophoresis (CE) are described. The dual source CE power supply provides +/- 1 kVDC at 380 microA and can operate continuously for 15 h without recharging. The amperometric EC detection circuit provides(More)
Remote unattended sensor networks are increasingly sought after to monitor the drinking water distribution grid, industrial wastewater effluents, and even rivers and lakes. One of the biggest challenges for application of such sensors is the issue of in-field device calibration. With this challenge in mind, we report here the use of anodic stripping(More)
The development of microfabricated electrochemical systems suitable for deployment in sensor networks that operate with a minimum of operator intervention are of great interest; therefore, a coulometric sensing system for exhaustive coulometry with the potential for calibration-free operation has been designed, fabricated and evaluated to support such(More)
Improving techniques for portable trace analyte collection and pretreatment is of critical concern for security, medical, food and environmental applications. The trend has been to employ MEMS technologies to meet this need as these microfabricated devices offer advantages such as small dead volumes, low power consumption, capacity for large scale(More)
Suspended microchannels suitable for electroosmotic flow were fabricated by coating and dissolving sacrificial polymer fibers created by a new technique which involves using a pressurized syringe loaded with solution to directly deposit filaments of solution on the substrate in a " connect-the-dots " style. Additionally, because both the stylus and syringe(More)
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