In the 1960s, NASA engineers pioneered a next-generation space suit for the most famous space exploration program in history. Woven fiberglass was coated with DuPont’s Polytetrafluoroethylene (PTFE) to form a membrane which became the base material used by the Apollo astronauts, including Neil Armstrong and Buzz Aldrin. This high-tech material protected the astronauts from micrometroids and abrasive lunar dust as well as harmful solar radiation and the threat of fire.
This durable material possessed all the qualities that bolstered its transition to an architectural product in 1973; the Teflon®-coated woven fiberglass membrane is extremely durable and weather resistant. The translucent, high-strength material made its debut on the LaVerne College Student Activities Center, which still exists today. The material went on to be the cornerstone of iconic projects such as Cynthia Woods Amphitheater (The Woodlands, TX) and several retractable-roof stadia.
A similar story exists with another material developed by DuPont, originally developed as an industrial product due to its excellent chemical and electrical resistance properties. Ethylene tetrafluoroethylene (ETFE), a fluorine-based plastic, was repurposed in 1982 as a roof cladding for an exhibit at the Burgers Zoo in Arnhem, Netherlands. From there, the ETFE pneumatic system went on to star at the 2008 Beijing Olympic Games as the cladding on the iconic Watercube Aquatic Center. Transparent foils, such as ETFE, are quickly becoming the preferred solution among architects and engineers. For example, the iconic KC Live Entertainment District is the first single-layer ETFE application in North America.
Both technologies are excellent examples of quality cladding systems whose roots originated outside of the architectural mainstream. Both, however, have their limitations and are showing their age. PTFE fiberglass is over four decades old and ETFE is three decades old (in addition to being very limited in strength, requiring it to be installed in a pillow form for structural stability). Single-layer applications require significant amounts of cables or steel to support the ETFE material, often leading to excessive material and installation costs.
So what is the future of membrane and foil cladding systems? Smart materials, in contrast to conventional materials, are dynamic in nature, meaning that their properties can be changed by an external condition such as temperature, light, pressure, or electricity. More simply, smart materials respond to and interact with their immediate environments to exhibit adaptive characteristics that fulfill previously impossible functions. New, technologically superior cladding materials and systems are on the near horizon and will continue to reinvigorate the design community and re-shape the built environment as new architectural forms and structural feats are made possible.