Engineering Student Redesigns Casing for Deodorant, Wins
National Contest

by Elizabeth Luciano
News Office staff

January 28, 2000

Nearly two years ago, Mechanical and Industrial Engineering student Nathaniel Mulcahy bumped into the bathroom sink, and his Mennen Speed Stick smashed to the floor. "What a lot of bits of plastic," the Mechanical and Industrial Engineering senior thought as he cleaned up the mess. Then he decided to build a better deodorant stick. Mulcahy's resulting "Speedy Speed Stick" led him to win the student contest at the 1999 International Mechanical Engineering Congress and Exposition in Nashville, Tenn., late last year.

Mulcahy bought two cases of Speed Sticks --nearly 300 of them -- and handed them out among "friends, teachers, and strangers" in the College of Engineering. He needed to determine what the "wear patterns" were after real people used the sticks. Two weeks later, he collected the deodorants and found that there were three primary categories of wear that occurred on the surface of the deodorant, depending on the position of the arm under which it is applied. Using what he learned in professor Byung Kim's manufacturing processes class, he began his design by hand, then moved on to 3D computer modeling for more specific images and structural analysis. The process took about a year.

Mulcahy also evaluated the usefulness of each part of the deodorant's plastic casing. He found that the separate inner cap, which gives the deodorant a rounded top edge, is used only during the assembly process. It is intended to be thrown away as soon as the consumer opens the package. Mulcahy considered this needless waste. In the re-design, the inner cap has become a curved inner surface of the outer cap. In all, 11 original parts have been reduced to four. Mulcahy realized that jobs could be lost as the number of parts in the design was reduced, so the parameters of the project grew to include not only a reduction in the plastic parts of the package, but also zero loss of manufacturing jobs among the people making those parts.

G. Albert Russell, associate professor in the Mechanical and Industrial Engineering Department, suggested that Mulcahy enter his designs in the contest sponsored by the American Society of Mechanical Engineers (ASME) being held in the Campus Center at the time. His "Speedy Speed Stick" won locally, and Mulcahy was invited to compete at the ASME Regional Student Contest in Dartmouth last spring. "I was shocked to win," said Mulcahy, who entered engineering school after a 10-year career as a teacher. "I was up against some amazing designs." Mulcahy went on to compete in the national competition in Nashville in November 1999.

Mulcahy is now finished with his deodorant project and is focusing on his applications to graduate schools. If there is any money to be made from his deodorant design, it will be donated to the Lemelson Assistive Technology Development Center, a division of the Lemelson National Program at Hampshire College. The center provides students with the opportunity to design, develop, and make available equipment for people with disabilities. Mulcahy's donation would fund projects aimed at helping disabled children. He plans to keep just $500, to cover the costs that went into his research project. "It's not right for me to make money off an accident," he said. "It was a gift to me and it will be a gift to the foundation if someone buys the rights to the research," Mulcahy said. "I don't feel it is my right to keep it."

After graduate school, Mulcahy aims to found a company that would produce affordable prosthetic limbs for children. These prostheses often cost as much as $48,000, because they must be custom-designed. Many insurance companies won't pay for the devices because children outgrow them so quickly, he said. Hence, these children never develop the upper-leg muscles that would allow them to wear prostheses as adults. "We're condemning generations of people to live in wheelchairs, and it doesn't have to be that way," he said.