"If you listen to any '50s doo-wop music, there's one progression of four chords that was extremely common,"
explains Professor Michael Duffey of the Department of Engineering Management and Systems Engineering.
"It's called the '50s progression' or the 'ice cream change'." So, naturally, when Duffey gave his
undergraduate students a systems engineering senior design project that required them to build a
programmable thermal organ that could play this progression, they called the project the "ice cream change."
Duffey is a strong proponent of "hands-on" learning as a complement to the applied mathematics of optimization
and stochastic modeling that is the core of the systems engineering curriculum. "To teach core systems engineering
principles to undergraduates, they need to get their hands dirty with projects," he says. To accomplish this, he
created a new approach last semester to the department's senior design course and came up with the thermo-acoustic
The project combines simple robotics and a small, table-top energy device called a thermo-acoustic laser to
produce an integrated "system of systems" that can perform a piece of music. The energy sub-system consists of
a series of test tubes, each with a piece of honeycomb ceramic, which when heated make a loud sound.
The robotics sub-system consists of servo motors with crank-and-piston mechanisms controlled by the microprocessor.
The pistons vary the lengths of the tubes. "The idea was that they could hook the motors up to a computer, and a
piece of software could control the changes in frequency," states Duffey. "It's kind of like a trombone."
While a project called the "ice cream change" may at first glance seem less than serious, Duffey is very serious about
the project. "We tried to treat it just like a real world design project," he says. He divided the students into
various sub-teams with each working on a different sub-system: some worked on the structure, some on the software
programming, some on the robotics system. "We put up a schedule for the whole semester that included developing
the proof of concept designs, procuring parts, and conducting formal design reviews. We structured it like a project
at NASA and we used the format NASA uses to review projects."
Duffey hopes that projects such as this will introduce students to some of the same techniques and methods that are
necessary to make large technical projects work. He uses the recent Deepwater Horizon oil spill as an example.
"You had all the best engineers in the world trying to figure out how to plug that darn hole," he remarks.
"Part of engineering is being able to work in a team where you have a lot of unknowns. You're drawing from your
core technical knowledge, but some of it is improvised. You can't learn that from a textbook but it is engineering."