SCIENCE AT THE EDGE SEMINAR SERIES

Interdisciplinary Physics Seminar

Friday, 11 November 2011 at 11:30am

Room 1400 Biomedical and Physical Sciences Bldg.

Refreshments at 11:15

Speaker: Jay W. Grate
         Pacific Northwest National Laboratory

Title:   Pore Network Microfluidic Habitats & Structures for the Visualization
         and Study of Microbial Communities & Carbon Sequestration 

Abstract:

Microfabrication of planar microfluidic flow cells patterned with an array
of pillars creates a pore network in a two-dimensional format that can be
visualized through a transparent cover.  These pore networks provide a
representation of porous media that can enable study of chemical and biological
processes in microenvironments, to control advection (flow) and diffusion, to
create gradients, and to investigate pore-scale fluidic processes such as the
displacement of one liquid with another immiscible liquid.  The ability to
apply a variety of imaging methods to processes within these microfluidic
structures is a key feature enabling diverse research applications.  At PNNL,
spatially-structured microhabitats are being developed as research tools for
studying microbial communities, with a focus on cellulose degrading organisms,
as well as fluid displacement and geochemical processes related to geological
carbon sequestration.  Gas concentration sensing using fluorophores deposited
within the micromodel enable measurement of oxygen concentrations and gradients.
Methods for imaging the depletion of solid cellulose by cellulose-consuming
organisms are under development.  The displacement of pore water by immiscible
fluids including liquid carbon dioxide has been visualized and quantified using
fluorescence microscopy, demonstrating pore-scale processes and displacement
instabilities that have consequences to geological carbon sequestration at the
macro scale.