Gordon Kirkwood has been fascinated by soap bubbles since he attached a wand to a bike some five years ago. He dialed in the perfect speed (11 mph) and rode it down the street, and was amazed by the delighted, sincere response he got from people. The obsession grew into an automated machine to blow precise soap bubbles, which he calls the CNC Bubble Iris.
He describes it as a “robotic art sculpture,” but really, it’s a CNC bubble blower. Here’s how it works: A bubble solution is dripped down a three-thread iris design, similar to the aperture of a camera. A 150-watt servo, run by an Arduno Uno with a Geckodrive servo amplifier, rotates the face where the strings are attached, wrapping them around each other so the solution drips down to the middle. Then it opens, spreading the solution out to catch the breeze. Then the servo rotates back to slice off the end of the bubble, leaving it to float free.
“People react to bubbles like nothing else,” says Kirkwood. They represent whimsy and unpredictability, though Kirkwood’s machine may take away some of the latter. The device uses high voltage to charge air particles — the same way an Ionic Breeze purifier does — and accelerate the air in precise locations around the iris. This will allow the machine to “tent” the membrane, and make precise shapes in the soap.
From here, it starts to get far out. Soap bubbles are made of water and soap, but also salt, says Kirkwood. Therefore, they are conductive. And with conductive bubbles, he says, he’ll be able to use them as condenser microphones for a musical performance. They may not sound any good, but whatever distortion they produce should at least be interesting.
Kirkwood also intends to take high-speed photos of the bubbles, especially as they collide with the faces of notable people, or as he uses electricity or touch to affect their shapes, something he calls “sculpting fluid membranes.” And with an array of many of the bubble blowers, he’ll be able to create patterns of bubbles in three dimensions. “I’ll be able to 3D print bubbles on the wind,” he says. The 150-watt servo is fast enough for precise actuation.
Right now, the device is mounted on a stand, and tethered to an electrical outlet, but Kirkwood plans to make it a closed system so he can — what else? — mount the device on a bike, allowing riders to trigger bubbles with just the press of a button.