//CONCEPT
“I wonder how much it would cost to buy a soap bubble, if there was only one in the world.”
Mark Twain
Liquid bubbles are one of those things in life that are joyous in their simplicity and inexplicably fascinating. Not only fun to make, but equally as gratifying to chase around and pop. This project takes the real life experience of making bubbles and enhances it through technology by giving people the ability to make bubbles of various forms. A bubble wand can be dipped into one of three glass jars to select the type of bubble. Each glass jar represents one of three different bubble forms. The wand can be waved around or blown on to create bubbles which will appear on a screen projection in front of the person. Loud shouts or claps will pop the bubbles.
Early Design
//PHYSICAL CONSTRUCTION
Evolution of the Bubble Wand
VERSION 1: My first working prototype was constructed out of a plastic straw, plastic spoon, and jumper wire. Tested successfully with two sensors, a piezo and an accelerometer.
VERSION 2: The plastic straw was replaced by a stainless steel spoon straw. I tested color tracking with a glow stick to simulate the effects of EL wire as a light emitter. The main problem with the glow stick was that the bubbles did not originate from a single point but all around the wand, which was not the realistic effect I was looking for. I also removed the accelerometer because bubble generation through waving could be achieved with color tracking in Processing. This was a relief as the accelerometer itself would have proved difficult to attach to the wand aesthetically.
VERSION3: Tried a third version of the wand hoop using 3 flat IR LEDs and limiting the surface area of the wand that would emit light but still covering three main points, especially at the top to trigger the photocell that would be placed underneath the jar. The effects were still unnatural with bubbles appearing from three distinct and far apart points. Also it seemed that these smaller emitters were not as powerful as the 3mm IR LEDs.
VERSION 4: The final version of the bubble wand has two IR LEDs placed side by side near the bottom of the hoop to provide a single point light source. (The threshold of the photocell was adjusted so that the IR LEDs could be sensed even from a diameter’s distance.) Jumper wires were replaced with a thick copper wire for the hoop to be sturdy enough to withstand constant impact with the glass jars.
Box Construction
My first step was sketching out the dimensions of the box. Several parameters were considered: it needed to be long enough for three glass jars, the size of the wood needed to fit within the bed of the laser machine, and lastly, it also needed to be deep enough to house an Arduino and wires comfortably. I chose to use a compressed wood purchased from Home Depot.
The ITP laser cutter in action.
Boards cut and ready to be pieced together with Elmer’s wood glue.
Final box, with multi-colored mirrored plexiglass to better hide the photocells and refract light to give the jars a more bubble-like appearance. Three visible light filters are fitted over each photocell to limit ambient light interference between the IR LEDs on the bubble wand and the photocell.
//ARDUINO TO PROCESSING
The Processing component to this project involved the use of three libraries – serial, video and minim (sound). One of my first steps was getting the Arduino and all four sensors (3 photocells and 1 piezo) to speak to Processing. After successfully doing that, I proceeded to design the bubble shapes and finesse the movement of the bubbles and implement the bubble popping interaction. For testing purposes, a piece of visible light filter was taped over my Macbook’s iSight camera to limit the interference from other bright light sources and allow for more precise IR detection.
An early version of a visible light filter using developed 35mm film, which proved ineffective.
Testing photocells and color tracking.
Testing the Minim library. Used AudioSample for the sound of bubbles appearing and bubbles popping. Used AudioInput to detect loud sounds to trigger the popping.
//FINAL PRODUCT
//FUTURE CONSIDERATIONS
Moving forward, I would like to figure out a way to incorporate a Bluetooth component to the wands to make it wireless. This was experimented with briefly, but was not incorporated into the final presentation due to some last minute coding/technical issues involving whether Processing could process two serial events (one from the wand’s bluetooth for the piezo) and another from the photocells. I also would like to take this project to a much larger scale. To do this, I would need to incorporate a better infrared transmitter or look into a wide-range camera for better infrared detection.