NSF support for Engineering a Better Economy includes

• Developing fundamental new technologies for long-term economic growth, such as technologies to enable ultrafast computers and ultrasmall, nanoscale manufacturing

• Designing practical, cost-effective, environmentally friendly manufacturing and energy technologies, such as hydrogen fuel cells and industrial processes that avoid the use of toxic solvents

• Developing advanced, flexible manufacturing techniques, such as rapid fabrication and prototyping technologies

Imagine the computer chip factory of the future . . .
where “dry” industrial processes avoid millions of tons of wastewater, virtually eliminate the use of environment- and health-damaging chemical solvents, reduce chip defects, and substantially lower construction costs.

Joseph M. DeSimone of the University of North Carolina–Chapel Hill and North Carolina State University and his colleagues at the NSF Science and Technology Center for Environmentally Responsible Solvents and Processes are developing innovative manufacturing methods that save money as well as reduce pollution.

Based on the use of liquid and supercritical carbon dioxide (CO₂) as a cleaning agent and reaction medium, the technology eliminates the large streams of wastewater and airborne emissions created by conventional processes.

The new technology is already being used in a new chain of dry-cleaning stores called “Hangers,” where liquid CO₂ replaces the volatile organic solvent perchloroethylene, a known contaminant of groundwater. In addition, DuPont has adopted the technology in a new $40 million Teflon manufacturing facility, which unlike plants using the conventional water-based process, does not use a pollutant known as C8.

Micell Technologies, a private company co-founded by DeSimone, is now targeting the cleaning process for wafers and chips in the microelectronics sector as the next important industrial application of the new technology. Processes involving CO₂ could be especially important in cleaning components with fragile nanostructures, which would collapse under the high surface tension of water (liquid CO₂ has virtually no surface tension and the surface tension of supercritical CO₂ is zero by definition). Because of the enclosed nature of CO₂–based processes, new computer chip manufacturing plants using this technology may have less need for “clean rooms” and thus be less costly to build than those featuring conventional cleaning technologies.