Tom is the director of IEE, professor of Agricultural and Biological Engineering. His Bioconversion Research Group applies fundamental engineering science to microbial ecosystems, developing innovative strategies for a more sustainable agriculture and the emerging bio-based economy. A particular emphasis is on microbial processes that occur in three-phase porous media, where solid, liquid, and gas phases all play critical roles. These porous media systems are referred to variously as: solid-state fermentation in the biotechnology, pharmaceutical, and food processing industries; composting in the manure management and solid waste realms; ensilage on dairy and beef cattle farms; and soils in agroecosystems. The complexity of these systems lies not only in their immediate physical, chemical, and biological dimensions, but also in the human and natural systems within which they are embedded. Understanding and improving the performance of these microbial processes demands a multi-dimensional perspective and invites interdisciplinary collaboration.