The team took on the challenge of designing a metallophone (a type of metal instrument that produces sounds based on vibrations of the instrument itself, rather than a reed or strings). Because shape is so important to the instrument, the design process is typically complex and slow. And because of that, we've been limited to boring, simple bars instead of interesting animal shapes. Instead, Zheng and his team 3D printed elephants, lions, giraffes, turtles, and other animal shapes to make up the keys of the instrument. To obtain the desired pitch, machines perforated and deformed the pieces automatically using a set of parameters.