Doing more with less: a chair that reimagines structural intelligence
Designed around a single cut, the Flex Chair by Madhu Rajan is a perfect example of using a material to its maximum potential.
The Flex Chair is Madhu Rajan‘s thesis project, shown at ICFF 2025 in New York, a side chair made from a single shell of fibreglass-reinforced nylon. It has no articulating joints, no foam, no upholstery, and no supplementary structure beyond four legs. The chair’s capacity to flex and yield to the body’s movement is entirely a product of how it is shaped and where it is thinned.
It is complicated to make a chair that adapts to the human body properly, and the history of seating is essentially a history of solutions to this problem: mechanisms, springs, cushioning, each of them adding weight, complexity, cost. Madhu Rajan has approached the problem from the opposite direction, coming back to the eternal principle “less is more.”
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At the sides of the seat, the chair’s shell features a split, like a paper cut, which interrupts the continuous surface just enough to allow the backrest to move rearward under load. When you stop applying the load, it returns to its original position. The intelligence of the product is entirely in its geometry and material thickness.
“The concept draws from the efficacy of paper manipulation, how a single incision or fold can create dynamic movement without additional components. In the same way, the chair’s design introduces flexibility not through additional mechanisms, but through the inherent properties of the material, shaped and refined into a form that responds naturally to the user’s movements,” says Rajan.
This approach has precedents in the history of the moulded shell chair, notably from the early 1950s, when Charles and Ray Eames pioneered the fibreglass shell chair in collaboration with Zenith Plastics. The couple’s insight was that a single moulded surface could distribute the body weight across a wide area without the need for padding.
Still, their chair did not flex responsively in the backrest. Verner Panton’s 1960 cantilever chair achieved a degree of springiness through the chair’s overall geometry, with the whole chair acting like a spring instead of a single part. Herman Miller later developed shell chairs with H-shaped slots cut into the transition zone between seat and back, a mechanical intervention to allow flexing.
Fibreglass-reinforced nylon is a precise choice for the Flex Chair, stiffer than polypropylene, but can be engineered to flex predictably at reduced cross-sections. Unlike most reinforced polymers, which can creep or deform under sustained load, glass fibre reinforcement helps the material return to its natural position. This is like what engineers call a “living hinge” application, where flexibility is derived from thinning a section of a continuous structure rather than introducing a separate joint.
Rajan achieved this result through extensive prototyping iterations, because this kind of work requires physical testing more than computational modelling. The material itself teaches you what it can and cannot do, and the form adjusts accordingly. As the current furniture market is crowded with chairs that achieve ergonomic performance through visible and invasive technology, the Flex Chair operates from the premise that the best performance is the kind that disappears.
