This
is another one of those happy meetings of art and engineering. They call
it Blow Up, because it can magnify your breath.
A dozen small fans, or impellers, sit in a compact four-by-three array
on a desktop. Across the room, there are a dozen big fans arranged the
same way in a frame. The basic idea seems to be that, when anyone blows
on the little fans, the big ones will answer in the same pattern and everybody
grins into the breeze.
(You don't have to take our word for it. You can see for yourself at www.snibbe.com/scott/breath/blowup/
video.html.)
The artist, Scott Snibbe, calls it an installation, and as you'd
expect of a multidisciplinary project, he worked with a crew that included
engineers and designers to put it together.
Appropriately enough, given the physical nature of the piece, Blow Up
begins and ends with the work of a mechanical engineer. Michael Wehner,
a Ph.D. candidate in mechanical engineering at the University of California,
Berkeley, designed and engineered the breath console. Brett Bowman, an
engineering manager for Hiemstra Product Development in San Francisco,
designed the fan wall and the system that powers it.
 |
| Blow Up, an installation combining art and engineering, as it appears in a video on the artist's Web site. |
Snibbe, who says his primary medium is video, has done other, smaller
breath works, including one called Mirror, which works a little differently
from Blow Up. Mirror, which you can also see on Snibbe's Web site,
looks like an old radio microphone crossed with a table fan. The impeller,
tucked inside the mike, is an electrical generator using a magnet and
coil.
According to Snibbe, a drive signal is produced by greatly amplifying
the signal generated as the impeller rotates a magnet inside a large coil.
The signal is directed to a motor driver, which operates at speeds proportional
to the voltage level.
Art has become his full-time job, but he once worked at Adobe Systems
on After Effects special effects software, and also at Interval Research
on digital video research, computer vision, and haptics.
Mirror's system has too much noise in it to run something on the
scale of Blow Up, Snibbe said. In the larger installation, the blades
of the impellers are there for visual effect. The work is done by solid-state
sensors in the center of each impeller. Electric circuits keep the transistors
at a constant temperature. If you breathe on them, convection cools the
sensors, and more electricity is applied to keep heat constant. That change
in current is digitized, stored in microcontrollers, and then amplified
so a dozen fans can mimic the pattern of your breath.
The fans are mounted on an aluminum frame assembled of parts made by 80/20
Inc. in Columbia City, Ind. The company says its name comes from a theory
by an Italian economist, Vilfredo Pareto, who judged that 80 percent of
one's results come from 20 percent of one's efforts. Snibbe
said it was a guiding idea for the entire Blow Up project, to choose parts
that would save time, or give 80 percent of the result for 20 percent
of the input.
The direct-drive brushless motors that drive the fans are a case in point,
he said. They are Smartmotors from Animatics Corp. in Santa Clara, Calif.,
and saved engineering time because they included the amplifier and control
electronics.
Most components for the wall were off the shelf. According to Bowman,
the mounting plate to attach the motor and a short driveshaft to couple
the fan to the motor were the only custom-machined parts.
Blow Up was commissioned by the Yerba Buena Center for the Arts in San
Francisco, where it was shown several months ago. There are talks about
putting it in London's Institute of Contemporary Art sometime next
year. Sooner than that, the installation's next venue will be Austria's
Ars Electronica exhibition. So if you're in the neighborhood of
Linz during the first week of September, you can stop in for a breath
of fresh air.
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