School Notes: School of Engineering & Applied Science
May/June 2009

Yale engineers revolutionize nano

Yale engineers have created a process that may revolutionize the manufacture of nano-devices from computer chips to biomedical sensors by exploiting a novel type of metal. The material can be molded like plastics with nanoscale detail and yet is more durable and stronger than silicon or steel. The work was reported in the February 12 issue of Nature. (For a Yale Alumni Magazine report and photo, see "Eau de Nano.")

The search for a cost-effective and manageable process for producing higher-density computer chips with nanoscale precision has been a challenge. Researchers have been exploring the use of "amorphous metals" known as bulk metallic glasses (BMGs) for about a decade, according to senior author and professor of mechanical engineering Jan Schroers. BMGs do not form crystal structures when they are cooled rapidly after heating, and although they seem solid, they are more like very slow-flowing liquid that has no structure beyond the atomic level -- making them ideal for molding fine details.

"We have finally been able to harness their unusual properties to transform the process of both making molds and producing imprints," Schroers said. "This process has the potential to replace several lithographic steps in the production of computer chips." While "plastics!" was the catchword of the 1960s, Schroers says, "we think 'BMGs!' will be the buzzword for the coming decade."

Engineering undergrads step beyond the theoretical

While Yale has long since dropped its formal program in civil engineering, members of the Yale chapter of Engineers Without Borders (EWB) are receiving hands-on civil engineering training, sometimes far from the classroom. EWB-USA is a nonprofit humanitarian organization established to partner with developing communities worldwide to improve their quality of life through the implementation of sustainable engineering projects and training of responsible international engineers and engineering students. The Yale EWB chapter was founded in 2004 by associate professor William Mitch. Since its inception, it has tackled two significant water resource challenges: the first in El Rosario, Honduras, and the second in Kikoo, Cameroon.

This past December, EWB made its third trek to Kikoo, a village whose primary drinking water source, until recently, was a stream rife with E. coli and other fecal coliforms. With the support of the villagers, in excess of 10,000 man-hours, EWB has succeeded in supplying spring water to a portion of the community. The team also led sanitation classes in the primary school and taught village leaders how to test the system periodically for bacterial contamination.

The group is working diligently to raise funds for a return trip next year. In the interim the team will move ahead with design plans and training workshops in the local area. They always welcome the participation and expertise of alumni and donations of old equipment.