Bubble Talk: Turn Your Speech Into Bubbles!

”quod, ut dicitur, si est homo bulla, eo magis senex

(for if, as they say, man is a bubble, all the more so is an old man) ”

- Marcus Terentius Varro (116 BC - 27 BC), De Re Rustica

A soap bubble is ephemeral. It lasts only for a brief moment and quickly disappears even by a light breeze. The bubble's symbolic meaning as a metaphor of human's fragile and insubstantial life was first coined by a Roman writer Varro in the 1st century BC. Also, in 1572 the philosopher Erasmus reintroduced the Latin expression ''Homo bulla'' (''man is a bubble'') in his collection of proverbs, Adagia. This special characteristics of bubble attracted lots of artists in 17th century and also other periods. A paint, 'Cupid Blowing a Soap Bubble (1634)', by Rembrandt Harmensz van Rijn is one of examples. Metaphor of bubble continues to the modern century and a modern artist, Thomb Kubli, also uses bubbles as a media to transfer invisible and intangible sounds to visible but fleeting form in a 3D space.

The attractiveness of bubble might be coming from its ironical representation of our transient life which reminds us of the value of our existence at a moment and makes us seize the present.

Step 1: Inspiration

A word and shape of 'bubble' were used as a graphic convention describing a imaginary form of speech and thought of characters in comic books. Inspired from those metaphors of bubble, I introduce an interactive art/ toy project representing the ephemeral and intangible properties of human's communication.

Once speech is shouted out from a speaker, the sound of speech never lasts and it lost its meaning unless there is a listener. Even if the speech is heard by someone, the message will be forgotten as time goes. The shapeless, intangible, and invisible speech is transformed into a semi-tangible yet still insubstantial form of visible bubble. To present this art concept, I created a bubble machine that provides person-to-person and person-to-space interaction.

The machine has a iris mechanism that varies its outlet size reacting to your speech pattern as if it tries to speak something. Once the participant pauses, a fan inside of the machine generates airflow toward a bubble membrane created on the iris outlet and transforms it to various sizes of bubble.

The floating bubble represents the subtle state of a message from interpersonal communications that lies in the middle of real and digital world. Also, it creates a few seconds of delay until it explodes, through which we like to say that it is never possible to have a real-time synchronized communication between two people even in a same space due to the limit of human perceptions.

I'd like to invite all of you guys to be an artist through playful interactions with the 'Bubble Talk' machine! :D

• Iris Mechanism

Inspired by the amazing great work The CNC Bubble Iris by Gordon Kirkwood, this project introduces the way to build a bubble iris machine in smaller and mobile size using 3D printer and Laser cutter, and shows you to make it interactive to your speech to have fun!

As Gordon Kirkwood well explained in his instructables post, the core mechanism of the machine is iris using strings.

Step 2: Materials You Need

Here is the link for the materials I used to build a iris bubble machine.

Material List

I used to a laser cutter to cut the acrylic sheet and a 3D printer to print some components (bearing mounts, servo mount, pulley etc.) For the outer structure components, I used Form2 with Clear V4 material.

Step 3: Schematics and 3D Files

Here are the STL files for 3D printing parts, and PDF file for laser cutting part.

• STL Files for 3D Printing
  

https://drive.google.com/drive/folders/1EcchA65buvjBsyPmMD-R2n_9MbgLdhrV?usp=sharing

Quantity for each part is stated at the end of the file name. (e.x. Servomount_1EA.STL)

• 2D Schematics for Laser Cutting
  

https://drive.google.com/drive/folders/1do6HraR7O8gMoUk7EMBF5PTJL62ruPnI?usp=sharing

• PCBs: DC Motor Driver, Microphone amplifier.
  

At the time I was building this project, in my lab I didn't have a microphone amplifying board and DC Motor driver but an Electret Microphone, several electronic components, so I designed a simple board and milled using CNC machine (Roland Modela MDX20 CNC Mill) with copper board

In case you want to mill your own boards, here I also attached the EAGLE schematics and image file for CNC route. Or you can just use the product from Adafruit or any other provider.

Step 4: Fabrication

• 3D Printing and Laser Cutting
  

To meet the purpose of an art toolkit for everyone, I tried to use easily accessible material and fabrication equipment. I laser-cut a acrylic sheet to create a structure of the Bubble Talk machine as shown on figures above. Other parts that requires strength and certain 3D shapes are 3D printed using a customer level filament-fused (Sindoh 3dwox) or stereolithography 3D printer (e.g. Form 2).

• Soap Bubble Liquid Recipes

In the Soap Bubble Wiki Page, it introduces variety of different bubble soap liquid recipes.

I followed the Mike's "Gooey Mix" as Gordon recommended on his post too.

You can also find all the product link for making this liquid in my material list sheet I shared.

Step 5: Assembly

Once you have all the 3D printed parts and acrylic sheet cuts, and assembly components (bearing, cotton thread, spring, fan, MCU, etc.) Follow the process as shown on the pictures above.

1. Horizontal (3 ea) and vertical (6 ea) bearing assembly with 3D printed mounts (purple parts on the picture)
2. Fix the bearing mounts with bearings on the acrylic sheet for the front face structure
3. Insert the white acrylic rings that can be rolling around the bearing smoothly
4. Fix the pump and servo motor on the front face structure. (servo should be mounted on the 3D printed servo mount first)
5. Assemble 3 pulleys on the front structure (it has three holes matching with the pulley's inner hole diameter)
6. Cut the cotton string to be 3 threads and tie them with spring
7. Fix the other end of spring on the 3 points and make the thread go around the pulley. (The spring has a role of maintaining the enough tension on each string (always should be tight)
8. Tie the string ends to the white acrylic ring's hole. Make sure to have the 3 strings are crossing each other forming a triangle. All the thread should contact each other on the 3 points of triangle.
9. Fix the servo pulley (blue part on the picture) on the servo's shaft
10. Circle around the pulley with a fishing line about 2 cycle, and make a cross at the end (The fishing line connects the motion of servo and acrylic ring working as a driving belt.
11. The each end of the fishing line should go round the white acrylic ring and fixed on it with a spring (this spring works as tension keeper)
12. Cut a copper tube and connect it with the pump's outlet to guide the soap liquid around the strings
13. Assemble a DC fan in the middle of the back structure of the machine
14. Put the outer structure (3D printed) around the back structure and glue it using a epoxy glue
15. Cover the top with the front face structure assembled with servo, pump and strings.
16. Done!

Connect the DC motor driver with the pump and DC fan. Connect the microphone with amplifying board and servo to microcontroller (e.g. teensy, Arduino, etc.)

Step 6: Test and Have Fun!

Now it's all assembled and ready to be run!

The input for the machine is your speech and the output is opening of iris creating a soap membrane and running of fan to blow it out.

Make sure all the power is correctly connected, check the polarity before run the machine.

Depending on the fan's speed and the iris size (soap membrane surface area), the size of bubble and its emission motion are varied. I'd recommend to run several times to tune the parameter of fan speed and run timing in relation with the servo actuation for iris mechanism open/close.

Sometimes, the machine makes very funny motions like a teddy bear snoring with bubble coming out from his nose.

The material list I shared also includes the parts needed for making the machine mobile with Lipo battery, so try with that and playing with it walking around outside.

Have fun! and Talk through Bubbles!