As kids, making and chasing bubbles was a source of great entertainment. For some of us adults, it may still be. In architecture, the idea of bubbles has inspired innovative use of materials in order to create enclosures that may not have otherwise been structurally possible or would have severely lacked experiential quality. Two projects highlight the idea of the bubble in architecture, and the material and structural innovation that led to.
Completed in 2000, the Eden Project is a series of artificial biomes created in an abandoned mining pit in Cornwall, UK. Two design issues drove the development of the enclosure shape. The first issue was to create a large enough area to house each biome and its plant mass while the second required that sunlight be able to penetrate the living biology inside. These design challenges led to the use of a geodesic dome as the structure but filling the spaces between the hexagons became problematic. The weight of glass and its tolerance meant looking for a different solution. Designers and engineers eventually used a triple-layered pillow of ETFE (ethylene tetrafluoroethylene) plastic to enclose the frame.1 Not only does the ETFE weigh a tiny percentage of the weight of glass but it also allows more sunlight through. By inflating the layers of ETFE, designers were able to trap air between layers and provide a thermal barrier from outside.
A second project using ETFE to enclose a structural frame is the Beijing National Aquatic Center, nicknamed the “Water Cube”. Used for the 2008 Beijing Olympics, the Water Cube took inspiration from bubbles in an additional way. Its structural space-frame was designed to achieve long, unsupported spans with a method known as the Weaire-Phelan structure that simulates the way in which bubbles pack in nature. The seam along each “bubble” meeting another became a structural steel member. Between steel hexagon’s ETFE pillows .2mm thick complete the enclosure. Not only are light and thermal performance improved from the ETFE but the effect from the outside at night is a spectacular cube of blue, glowing bubbles.
Not only does the use of ETFE allow for the ability to build expansive enclosures, but the layering and pillowing of the material manipulates light creating unique experiential qualities. A recent proposal by Dillar Scofido + Renfro architects focuses on the potential experiential qualities of bubbles, or in this case, one large bubble. Planned as an expansion to the Hirshhorn Museum on the mall in Washington D.C., the “Bubble” is an inflatable event space planned for the cylindrical courtyard.2 In the architects’ words, “The Bubble is an architecture of air: a pneumatic structure enclosed only by a thin translucent membrane that squeezes into the void of the building and oozes out the top and beneath… the Bubble produces a soft building inside of a hard one in which existing and new spaces are intertwined.”3
Though un-built, the Bubble project will likely drive the need for a new material or advance the application potentials of a material like ETFE. Initially, the use of ETFE on the Eden Project and the Water Cube allowed the project to be physically achieved. Seemingly emboldened by the success of such precedents, the DS+R project proposal explores new experiential potentials of the bubble idea and challenges how materials like ETFE might interact with other materials.