SPECIAL SEMINAR Evaluation of laser-induced breakdown spectroscopy (LIBS) as a new in situ chemical sensing technique for the deep ocean

Speaker: Anna P. M. Michel, MIT/Woods Hole Oceanographic Institution Joint Program in Oceanographic Engineering

Date: Tuesday, February 20, 2007

Time: 4:00 PM - 5:00 PM Location: Room 3-133

Abstract:

Present-day expeditionary oceanography is beginning to shift from that of short-term ship and submersible deployments to that of an ocean observatory mode where long-term temporally focused studies are feasible. As a result, a critical need for in situ chemical and biological sensors is evolving. New sensors take a significant amount of time to develop; thus, the evaluation of techniques in the laboratory for use in the ocean environment is becoming increasingly important. Laser-induced breakdown spectroscopy (LIBS) possesses many of the characteristics required for such in situ chemical sensing and is a promising technique for field measurements in extreme environments. Unlike many other analytical techniques, LIBS can be used to analyze samples that are solids, liquids, or gases; thus, there are numerous possible applications of LIBS in the ocean including the analysis of rocks, sediments, and hydrothermal vent fluids. Although many LIBS researchers have focused their work on solids, very little attention has been paid to bulk liquid analysis, and especially to the effect of oceanic pressures on LIBS signals.

In this work, laboratory experiments validate the LIBS technique in a simulated deep ocean environment with a focus on studying hydrothermal vent fluids. The results suggest that LIBS is a viable chemical sensing method for in situ analyte detection in high pressure environments like the deep ocean. The results also demonstrate the feasibility of developing LIBS into a new oceanographic chemical sensor for the simultaneous detection of multiple elements.

Biography: Anna Michel earned Bachelor of Science degrees in Chemical Engineering and Biology in 1998 from MIT. She then went on to earn a Masters of Science in Ocean Engineering from MIT in 2002 in the area of marine hydrodynamics. Michel is currently a doctoral candidate in the MIT-Woods Hole Oceanographic Institution Joint Program in Oceanographic Engineering with research focusing on chemical sensors. When not working in the laboratory, Michel leads the MIT Women's Initiative, a program geared at introducing pre-college women to the field of engineering.