Approximately 14,500 people were killed in traffic crashes where the driver was legally intoxicated in 2005, constituting 33% of all traffic fatalities that year. While social efforts to reduce the number of traffic fatalities have shown to be moderately successful, alcohol has remained a factor in 40% of all traffic deaths over the past decade. Transdermal ethanol detection is a promising method that could prevent drunk driving if integrated into an ignition interlock system; potentially preventing 90 million drunk driving trips a year in the US. However, experimental data from previous research has shown significant time delays between alcohol ingestion and detection at the skin which makes real time estimation of blood alcohol concentration via skin measurement difficult. Using a validated model we studied the effects that body weight, metabolic rate and ethanol dose had on the time lag between the blood alcohol concentration and transdermal alcohol concentration. The dose of alcohol ingested was found to have the most significant effect on the skin alcohol lag time. Additionally, custom transdermal ethanol sensors were designed and fabricated and a pilot study on human subjects was conducted to determine if inexpensive transdermal ethanol sensors could be used to detect alcohol in drivers. / Master of Science

The goal of this research project was to characterize the physical and electrochemical properties of a commercially available fuel cell-based breath alcohol sensor. Characteristics of the existing sensor were compared with state of the art power generating fuel cells with the goal of understanding the factors that limit performance, lifetime and cost effectiveness of the sensors. This will guide the development of the next generation of breath alcohol sensors. The average lifetime of the current sensor falls short of the industry standards. In particular, sensors operating in dry conditions experience more rapid loss of sensitivity and failure. Two primary causes of degradation were investigated in this study. Loss of proton conductivity as a result of membrane dehydration was shown to be reversible by rehydrating the membrane in humid conditions. Loss of electrochemically active surface area of Pt is irreversible and seems to be caused by a change in sensor morphology after long-term exposure to dry conditions. / UOIT