For the 2011 ITP Winter Show, I worked with Bruna Calheiros to build an organ which plays perfumes.
My wife Eliza is a perfumer, so I have absorbed some of her knowledge over the years. Of particular interest to me (as a musician) was this chart I came across in one of her books:
The was devised by the 19th century perfumer Septimus Piesse as an aid to ‘composing’ perfumes.
Perfumers use many musical analogies to describe their art. Individual scent components are ‘notes’ — there are ‘top notes’ which dissipate quickly and ‘bass notes’ which dissipate slowly. Accords are build of multiple notes, and in less technical conversation perfumers speak of harmony and balance and even rhythm. Even the stepped shelves that house a perfumer’s bottles are referred to as the ‘organ’ because of its similarity to a pipe-organ.
I thought it would be very interesting to reify this metaphorical relationship. Thus, a musical keyboard which, when played, would release scent ‘notes’, while also playing corresponding musical notes, and for good measure associating these scents with colors.
Bruna has two very good posts on the design process, so I won’t repeat it here. In short, we built a device with a series of small computer fans controlled by an Arduino. When the keyboard is played, it sends a midi signal to a Processing sketch which then signals the Arduino board via serial link. The Arduino turns on the appropriate fans, which send a gentle stream of air past a scent-infused piece of felt and through the acrylic tubes to the nose of the user.
It worked surprisingly well; there was only a short delay from the time a key was played to the time the note could be clearly scented by the user. Chords were distinct; you really could compose perfumes with it.
However, my biggest regret was that, due to time and cost limitations, we were only able to incorporate six individual scents. I asked Eliza to pick two each of bass notes, heart notes, and top notes that she thought would go well together. (She chose, from ‘low’ to ‘high’, musk, cistus labdanum, rose, jasmine, aldehyde, and bergamot.) In my dreams, I would have loved to have three full octaves of scents to choose from, like the chart above. But overall it turned out pretty good.