Evan Peairs plays the mandolin, guitar, and bodhrán, the ancient drum used in Celtic music. Now he plays a "new thing with no name" that he invented himself, a musical instrument similar to a bell plate that the 2016 Reed College graduate designed from a slab of aluminium.

Peairs, who is majoring in physics, originally planned to write his senior thesis on the acoustics of church bells. Church bells were too expensive and difficult to make, so – as with many discoveries born of necessity or accident before his – he turned to bell plates. The bell plate is a percussion instrument made of a flat aluminium or bronze piece that, when played, makes a sound similar to a gonglike bell. Peairs wondered why the bell plate was always shaped like a rectangle, and decided to see what happens when it's not.

By using structural optimization techniques typically applied in other engineering disciplines, Peairs was able to analyze the unique fingerprint of a recorded church bell and then translate it mathematically into a two-dimensional spline curve. He took the next phase to the machine shop, where he cut that precise spline curve form from an aluminium block by using a waterjet cutter. The finished bell plate, punched free from the aluminium, sounded exactly like the church bell tone it was meant to replicate.

Since this was, after all, his senior thesis, Peairs was required to prove that the novel instrument he created really did match the sound of the original church bell. He did that by using electronic speckle pattern interferometry, which relies on laser beams to create image models of the spatial sound waves.

When Peairs strikes the bell plates, they vibrate. Those vibrations create disturbances and interfere with a laser beam that bounces off of the instrument and then reflects the beam – and therefore the data – back to a camera. The process generates a precise pattern of the sound. When Peairs and his Reed College thesis advisor, John Essick, compared the patterns of the church bell source and the no-name spline curve, they found that the acoustic portraits for the resonance they generated were identical.

Once Peairs knew he was on the right track, he started making an assortment of bell plates, including one that sounds like a pipe organ, another that mimics a xylophone, and even a trumpet. The process makes it possible to create new sounds, and the theoretical instruments needed to make previously unknown music, on the basis of knowing which sound you want and creating the shape to match it.

A similar project completed by computer scientists at Harvard, MIT, and Columbia Engineering showed how computer algorithms to design xylophone shapes can use 3D printing to create and control their sounds – a discovery that, like Peairs' own research, isn't limited to the musical world in its application or even to acoustics. The science can inform everything from bridge construction to computer designs.

Peairs says that most students in his department do their work in theoretical physics, but he welcomed the chance to complete his "Designing, Building, and Testing Novel Musical Instruments" thesis in a different way. The thesis, to be published by Reed College, kept Peairs immersed in multiple disciplines that are lifelong passions. His other pursuits span an eclectic range, from designing giant hamster wheels with a more whimsical Reed student group, to running the research nuclear reactor on site at Reed, but he hopes to move to California's digitally driven Bay Area and pursue a career in robotics.