Dr. Higgs conducts particulate flow modeling and experimental research that utilizes the basic principles of tribology, fluid and rheological mechanics. His Particulate Flow & Tribology Laboratory studies three different flows found in sliding contact interfaces:
These three dynamic flows involve nanometer, micrometer, and millimeter size particles flowing in a fluid medium. In the field known as Tribology- the study of friction, lubrication, and wear- these flows have each been studied for their ability to act as lubricants between mating surfaces, or as “reverse-lubricants”, as is the case with slurries in integrated circuit (IC) manufacturing.
One of the projects Professor Higgs is working on uses slurry flows with nanometer size particles to manufacture magnetic hard disk surfaces to near atomically-smooth levels for the purpose of developing extremely high capacity information storage systems. To achieve this, his team employs chemical mechanical polishing (CMP), a semiconductor manufacturing process used to engineer the surface to nanoscale roughness. Pursuant to the international semiconductor roadmap, his group is also working to achieve uniform material removal of copper, barrier, and dielectric layers on semiconductor wafers during CMP. In studying powder flows, the group is researching and developing high-speed, oil-free, rotating mechanical systems that will use powder as lubricants. In granular flows, nearly-elastic particles are set in colliding motion to accommodate the relative velocity between two sliding surfaces. Developing and modeling granular lubrication flow experiments would significantly advance particle flow research being conducted in the biomedical, agricultural, and geological science communities. Overall, the Particulate Flow & Tribology Laboratory will research and develop innovative mechanical and electrical technologies that are processed or protected by particulate flows.