7 in 7: Day 4 - Harmonics

Guiding Questions


From my presentations to external crits, I have cited a few precedents with standing wave patterns, such as that of a string rotated using a motor. I am curious as such a phenomena is common to string and wind instruments, where pressing down on a string alters its vibrating volume (such as in a guitar), similar to what closing holes do for wind instrunments. Often this is invisible and we can only hear the effects.

The Idea

For this prototype I want to explore using a luminescent material to visualize this vibration. I experimented with plastic rods of varying thicknesses, transparent as the intention was to pass light through internal reflection along the length of the rod.


I secured both ends to metal brackets using a glue gun, and stepping on the brackets to keep the tension.

I then plucked it and observed. I also tried passing light (flashlight from phone) into the rod to observe the effect. I also tried using strobe lights via an app to see if I could freeze the harmonic waveform as performed with lab equipment, an effect which I could not replicate.

I also tried using the slow mo video recording to see if I could get some interesting images.


Plastic rods did not catch light very well, but they have a rigidity that lends well to oscillations. A light tube materiaL I later acquired captured light very well, and could possibly be used once the tensioning is done better. It would be interesting to test what would happen in the case of fixing the oscillating material at a certain point, much like pressing on the frets of a guitar. Furthermore, this is just an exercise to see the visual aspects, where sound has not come in. Using the strobe light/slow mo method, others were able to capture the vibration of guitar strings as they were being played.

I would like to explore how to better increase the interactivity beyond just plucking or adding a bridge, in terms of what the users can do, like changing the tension or triggering tones and effects depending on where they pluck.