Visitors to the Dubai Mall can now encounter two spiral clusters of glass poles rising up to 14 feet from the pavement. The tubes are inhabited by colored electronic pixels which create genies of light floating in their containers. The poles look like groves of giant lightsabers with their stainless handles planted in the ground. They are screens without sides, and you can walk right through them.
Touch a pole, and a burst of colored light originates from your hand and expands for a second or two, accompanied by the sound of birdsong. Slide your hand up or down and you learn to throw a bolus of light which crashes either into the ground or sky and then spreads reflections to the surrounding poles. This propagation of light is accompanied by sound moving around you from pole to pole. Hold still for a few seconds and the light fills the tube like an expanding luminous gas while the sounds morph from representational to abstract.
The experience of stopping to play with these poles is akin to shaking raindrops from a tree, scaring birds into flight or making ripples in the surface of a pond. The children of the iPhone generation are enthusiastic visitors, and they know just what to do. The poles provide them with a familiar interface that is shifted in scale, form and context.
Designed and produced in collaboration with Howeler + Yoon Architecture, the installation is called Aviary and was completed in May 2013. It consists of two groves of poles, both arranged in tight spirals. The smaller group has 10 poles and its larger counterpart has 20. It is a reincarnation of the original concept for the Sound Grove in Washington DC, which was produced before the iPhone came along in 2006 and redefined touch sensitivity. Ubiquitous touch interfaces have conditioned people to expect immediate feedback from their electronic environments, so we knew that revisiting the idea today required an immersive experience with a continuous interactive surface, fluid video and sensors with minimal latency.
It was clear from the beginning that the project would require collaboration with others beyond the core partnership of HYA and Parallel. The story of the piece and its final realization is one that depended on the involvement of a wide team of people from around the world working together.
At the start of the project we hired engineer Deqing Sun, who had done capacitive touch sensing projects at NYU’s ITP and jumped right into developing prototypes and experimenting with different materials. We explored a number of surface materials but liked glass for its surface durability, compatibility with capacitive sensing and complex materiality. Early design ideas and a bench prototype used a Y shaped structural metal core clad in glass or acrylic ‘petals’, but the joints were wide and clumsy and maintaining a waterproof seal was difficult.
A glass tube was the clean design solution we needed, and it was made possible with structural engineers Hauke Jungjohann and Tom Reiner of Knippers Helbig onboard. Schott made the borosilicate glass tubing and HiTech Glas lined the tubes with a clear film which keeps them intact in the event of breakage. Knippers Helbig designed a base glazing detail which uses an elastomer to support the glass in its stainless socket, so impact loads to the tube are absorbed by the flexible joint.
All of the electronics were custom designed by Parallel specifically for the project. The larger poles can consume up to 300W of power and their bases are crammed with power supplies, a speaker cavity, and a multimedia control board. The controller is based on the Gumstix computer module and has circuity for LED video control, audio amplification, and wired networking. We hope to use it as open-source embedded multimedia platform for future work, and will soon release a software image for other multimedia artists to use.
Inside the poles are four sided cores of color LEDs spaced 18mm apart. The poles are low resolution displays; a larger pole is about 200 pixels high by 4 pixels around. The displays are primarily linear but images can also wrap around their seamless periphery. It was a hard call, but we decided to conceal the pixels with a diffusing film lining the inside of the glass. The film blurs the pixels and lowers the contrast, but keeps the poles simple luminous surfaces without LED hotspots.
The touchfilm itself presented numerous challenges. We needed a clear conductive material that is resilient enough to withstand sharp bends from handling – the classic clear material, indium tin oxide, is a brittle coating that would crack during the pole lining process. We settled on a film made by Carestream LLC that is made from silver nanowires deposited on a polyester substrate. Carestream generously offered material and technical support, but we couldn’t find anyone who would process the raw materials into the large sized films we required.
So we ended up fabricating the films in house, a process that required a number of techniques we’d never used before. Alex Marshall from Howeler Yoon came down to the studio and figured it all out – registration and laser structuring, screen printing with conductive inks, oven curing, lamination and bonding the film to circuit boards.
Tim Bishop had our Haas churning out parts. He applied high speed machining practices that we’d only employed on aluminum before to milling the numerous stainless components. The pole bases include a structural baseplate with a custom junction box and waterproof bulkheads to separate the speaker openings from the electronics. We picked up an old manual Okuma lathe to turn, bore and finish the base tubes. In the meantime we welded and painted the steel core and began the laborious process of integrating and testing the electronics.
The finished stainless bases were shipped to Germany for bonding into the glass tubes, while the baseplates were delivered to Dubai to be set into the pavement and wired. Extra tubes were shipped to Brooklyn so we could build a test installation here in the shop, which was used to master the process of assembling and erecting the poles. Finally, the electronic cores and touchfilms were air freighted to Dubai where they met the German glass.
Facing an extremely tight schedule, we brought Jason Cipriani on board to write the underlying software that controls the poles and a simulator to test the installations behavior on a single computer screen. Jason’s modular client/server architecture led to a number of diagnostic tools to help with pole production and testing, and allowed him to offload computation to a central system with little rework. Audio programmer Nick Joliat wrote scripts that playback and process the sounds of composer Erik Carlson. Jason stayed on to develop the visual content of the piece and followed us to Dubai for the installation.
A 4-axis setup for machining the perforation pattern in the stainless steel bases