The Green Vanguard: T is for Three-D Intelligence

Designed by Fuseproject

A task chair is, according to Yves Béhar, “the hardest industrial-design project one could take on.” First off, there are thousands of office chairs already out there, “9,000 of which look like each other,” Béhar says. And “you can’t hide the functionality in a box. Everything you see is there to serve a function. Every piece of structure has to work.”

Commissioned by Herman Miller to design a comfortable chair from scratch at an affordable price, Béhar’s San Francisco–based studio, Fuse-project, came up with a concept inspired by a suspension bridge. (The Golden Gate, of course.) Instead of boasting a mesh back like the Aeron chair and its offspring, the new chair has a frame-less back supported by a spine, or Y-shaped tower, anchored by a lower span. Over a three-year collaboration, Fuseproject and Herman Miller developed this idea into SAYL, a lightweight chair whose main feature is a “3-D intelligent” back. Rather than providing the uniform bounce of a mesh seat, SAYL has an injection-molded polyurethane version designed to give different degrees of tension for different parts of the body.

“Certain areas need a lot of flex, and others need more support, especially the lumbar and spinal area,” Béhar explains. “The question was how to do that with a lightweight material. The problem with a mesh material is that it requires a frame, which the body feels as it moves around. We envisioned a thin, lightweight open material injected with intelligence. When we started adding hinge points—thicker areas—we were able to tune up or down and match the ergonomic functionality.”

Initially, the project was conceived for overseas markets, but as the recession kicked in, it became apparent that a low-cost task chair could do well in North America too. The turning point came when, in early prototypes, the team established that the bridge concept was structurally sound: the frame could in fact be eliminated and the structural mass reduced. “We had an ‘Aha!’ moment, that everything could be different with this chair,” Béhar says.

In a synchronized and sometimes tense dance, Herman Miller wrangled anthropometric data and CAD models while the design teams built, tested, and destroyed successive prototypes with real bodies and machines. Digital models informed prototype tests and vice versa, in a feedback loop. In all, 25 prototypes were constructed at Fuseproject, and another 50 at Herman Miller’s Michigan plant. “A chair is easy to produce in the 3-D CAD world, but it’s significantly deformed with your weight in it,” notes John Aldrich, Herman Miller’s vice president of engineering. “You can’t predict it with a computer model.”

Achieving the back’s “3-D intelligence” required successive tests of makeshift prototypes (made from rope, straps, wood, and plastic) to locate the optimum “hinge points” that would support different parts of the spine. (Two Fuseproject studio designers, Bret Recor and Qin Li, offered their services to test the chair, as representatives of the upper and lower percentile range: Recor is 6’6”; Li, 5’2”.)

A process of elimination drove the design development and kept the cost down. “Each part had to work harder, do more, and help resolve problems with less material,” Béhar says. After testing 20 different materials, Herman Miller engineers and designers arrived at a new blend of thermoplastic urethane that was suitably durable, UV resistant, able to hold color, and easy to mold, and felt good to touch. The company’s Design for the Environment protocol ensured that the materials were safe and could be disassembled and recycled. Final designs for tooling also had to take into account the fact that the material is stretched and therefore 10 percent larger on the chair than off. Computer modeling for production, Aldrich says, was “the most complex thing we’ve ever done. It took over 8,000 man-hours, about seventeen weeks, to model the final tool part. I think thirteen individuals had a hand in it.”

The end result is a $399 task chair with a bulbous, biomorphic shape and an unusually light, dematerialized feel and weight. In striving for material reduction (and the ecological and economic benefits of less shipping and manufacturing), the team designed every part of the chair from scratch, except the castors. The buttons used to move the arms were eliminated in favor of a ratchet system, and the tension knob was hollowed out to remove 40 percent of the material. The chair’s synchronous tilt, which allows the back to recline at two times the rate of the seat, so the body can open up to achieve a comfortable recline, was also purpose-designed—a stripped down version of the Mirra chair’s tilt mechanism. “The challenge was how to get an equivalent performance for fifteen percent less,” Aldrich says.

If office chairs were once relatively simple assemblages of wood and metal, bolted steel and leather, or upholstered lumps of foam on wheels, today they’re ergonomic, lightweight performance equipment. The closest analogy is not furniture but running shoes. SAYL’s greatest challenge will be to win the confidence of potential buyers that the stretched, curving elastomer will hold up under duress. A 12-year warranty may allay concerns, but for the faint of heart, Béhar and Herman Miller designed a foam version. This one safely hides its intelligence in the upholstery.

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