Interactive Pneumatic Sponge Ball Accelerator

Craft & Design Science
Interactive Pneumatic Sponge Ball Accelerator

Friend of MAKE Niklas Roy built and installed in the Tschumi Pavilion in Groningen, The Netherlands this beautiful sponge ball apparatus to bring the joys of tangible particle acceleration to the people.  I love him for it.




What was the inspiration? In his words:

As I’m a fan of science and physics in particular, I find it a pity that the current particle accelerators make the observation of the little speedy particles so complicated. This should be something that a broader audience can enjoy! So when the Director of the Tschumi Foundation approached me and asked me if I’d like to build a machine inside their beautiful pavilion located in the center of a roundabout in Groningen, I saw my chance: I decided to construct a machine which would bring the tremendous joy of particle acceleration to everyone!

The heart of the system is a set of “particle bubbles” with a vacuum cleaner acting to reduce the air pressure in one bubble, leaving the other to equalize and suck a ball down its gullet in the process. 1000 balls flow through it at a rate of 13′ per second.



In order to make the experience interactive, Niklas created wonderful handprint touch sensor that allows people to reverse the air flow of the system, thus slowing and then reversing the ball direction.



Rather than use an existing touch sensor, he built an optical sensor from LEDs and photo resistors, illuminating it with 500 optic fibers arranged in the shape of a hand. I think this is an appealing and clear user interface — not much out there says “place your hand here” quite like the graphical outline of a human hand.




As a small bonus, check out the inside, semi-psychedelic perspective of a modified, tiny spy camera being accelerated through the system:


For more details, see the project page.

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John Edgar Park likes to make things and tell people about it. He builds project for Adafruit Industries. You can find him at and twitter/IG @johnedgarpark

View more articles by John Edgar Park


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