Driving the future of fabric structures
Today’s advanced technologies will drive the future of fabric structures.
Specialty Fabrics Review | June 2011
By Blaine Brownell
Fabric is one of the oldest materials humans have used for shelter; it remains an important material with diverse applications in design and construction today, and it will play an even more important role in the constructed environment in the future.
Predictions of energy scarcity and resource depletion, exacerbated by the burgeoning middle class in developing countries like China and India, point to ensuing decades of high commodity prices and fuel shortages. In these circumstances, existing resources and structures will be valued more highly, and traditional, energy-intensive practices like “raze and rebuild”—in which buildings are demolished to make way for others—will be less attractive. Instead, architects and builders will have to be more resourceful in their treatment of existing contexts and materials.
Fabric will be a critical ingredient in the post-peak oil economy. One of the lightest and nimblest of building materials, fabric is easy to transport and install, and has a relatively low embodied energy and carbon footprint—making it a choice material in adaptive reuse situations. Furthermore, new technologies demonstrate the extent to which fabric is a highly adaptive, multifunctional material, capable of addressing a variety of future building needs far beyond the level of passive sheltering.
Increasing energy scarcity will encourage buildings to harness their own power from renewable sources. Thin-film photovoltaics will play an important role in solar harvesting envelopes. Organic photovoltaics (OPVs) are thin films made of multiple nanostructured layers of semiconducting organic materials that can be fabricated using low-cost, mass-production processes, such as inkjet or screen printing.
Boston, Mass., architecture firm KVA Matx has experimented with ways in which OPVs may be integrated into architecture, combining flexible energy harvesting textiles with digitally fabricated structural elements. Their Soft House, for example, features 3-D knit, FR-coated polymer fabric with woven aluminum inserts, integrated printed photovoltaic cells and Li-ion rechargeable batteries—a system that generates more than half the daily power needs of an average U.S. household. As these technologies are further developed for the marketplace, we may anticipate the combination of KVA Matx’s textiles and framing to form an integrated fabric structure solution.
Future fabric structures will harness energy from the wind as well as the sun. University of California, Berkeley-based scientists have developed a textile that generates electricity when moved or twisted. The organic polyvinylidene fluoride (PVDF)-based fabric is made of nanofibers of electrospun piezoelectric material, and test samples have produced up to 30 millivolts of electricity in the laboratory. The material has demonstrated a 25 percent conversion efficiency rating, and will initially be used for clothing applications. Once this technology is scaled to building envelopes, piezo-electric textiles will be used to clad fabric structures that continually harness energy from the wind.
Fabric will not only harvest energy, but also utilize energy to transmit light and visual effects efficiently. Delight Cloth from Lumen Co. Ltd., Tokyo, Japan, is a light-emitting textile made of thousands of fiber optic strands. With a diameter of only 0.25 to 0.5 mm, the optical fibers are woven into a large translucent tapestry that can be hung vertically or horizontally, providing a low-energy light source. Developed by Japan-based Tsuya Textile Co. Ltd. in cooperation with the University of Fukui Engineering Center, the material is currently used for wall or ceiling treatments as well as banner signage or clothing, and may be used to emit a wide variety of colors of illumination. Future applications include the integration of optical fiber textiles into fabric structures that emit their own light.
Textiles will also be used to convey moving images and information. Fabcell is a chameleon-like fabric that changes color when conducting an electric charge. Developed by Dr. Akira Wakita’s , Information Design Laboratory at Keio University in Japan, Fabcell is a flexible fabric made of fibers dyed with liquid-crystal ink and conductive yarns. These materials are connected to electronic components and woven into a square textile. When a low voltage is applied, the temperature of the fabric increases, changing the color of the fabric. When arranged in structural matrices, Fabcells can display transforming images within the complex curvature formed by flexible textiles.
Architectural textiles will increasingly serve structural roles in buildings, providing durable shelter and thermal protection for occupants; air-supported structures will be an important part of this adaptable future.
Designed by Vienna, Austria-based architect Thomas Herzig, Pneumocell is an assembly kit consisting of inflatable building elements analogous to biological cell-structures, which can be connected in numerous combinations to form complete constructions. With a common polygonal edge length for all of the cells, the various element types fit together precisely. The cells are airtight and do not require constant inflation as in other air-supported structures. If one element is damaged, the other elements can still give support to the construction, and the damaged element can be replaced—much like cells in a biological organism.
In addition to inflatable textiles, frame-supported fabric structures will continue to flourish, providing shade and wind protection in the form of lightweight, low-embodied energy enclosures. Such structures are capable of exhibiting spatial complexity and multiple visual readings—appearing opaque during the day and translucent by night when illuminated.
The 1,800-square-foot bandshell at Central Park, Playa Vista, Los Angeles, Calif., exhibits these traits. Designed by Michael Maltzan Architecture, Los Angeles, the multifaceted, cantilevered steel structure clad in a fiberglass and PTFE textile appears to hover like a tethered blimp above the ground, its taut fabric skin partially obscuring the ribbed steel elements within.
Smart technologies will enable fabric to respond to changing environmental conditions. One type of response involves a transformation in fabric’s physical properties. Dow Corning’s Active Protection System is a smart textile that remains soft and flexible until it is struck by high-impact force, in which case the material instantly stiffens to help protect against injury. When the collision has passed, the material immediately becomes flexible again. Currently used in athletic wear and military uniforms, Active Protection System technology will impart greater resilience against extreme loading conditions in fabric structures as well. The active ingredient in the fabric is a dilatant silicone coating, which is a shear thickening fluid. The viscosity of this coating increases with the rate of shear, therefore defining it as a smart material that actively responds to changes within its environment.
Other smart textiles will allow intelligent control of complex systems in fabric structures. Shutters, from the MIT Media Lab, Cambridge, Mass., is a shape-changing permeable textile for environmental control and communication. It consists of a curtain composed of actuated louvers that can be individually addressed for precise control of ventilation, daylight incidence and information display. Shutters’ soft mechanics are based on the electronic actuation of shape-memory alloy strands. Each strand is controlled to angle Shutters’ louvers and dynamically adjust their aperture, regulating shade and ventilation for energy savings, as well as displaying images and animations.
Due to heightened demand for diminishing petroleum resources, future fabrics will be made of alternatives to petrochemical-based polymers. Notable departures from petroleum-based textiles include Teijin Fibers’ Biofront and Designtex’s Ingeo fabrics. These bio-based textiles derive their fibers from corn, an annually renewable resource. Bacterial fermentation is used to convert corn from a starch to a sugar and then to polylactic acid, which in turn is processed like most thermoplastics into fiber. These textiles point to sustainable, closed-loop manufacturing processes, since their biopolymer may be safely biodegraded at the end of its useful life. Bio-based textiles have been applied to building and car interior furnishings, and will eventually be scaled to buildings. Increasingly, corn-based textiles will utilize corn husks and other inedible parts of the plant so as not to strain limited food supplies.
Self-structuring fabrics will also be made from biocomposite materials. Developed by John Christer Hoiby as a collaborative thesis between the Department of Architecture and Department of Textile and Apparel at Cornell University, Ithaca, N.Y., Fiber Wall is a fully biodegradable textile-based panel system that consists of plant fibers and plant-based resin. Designed to combine properties such as high structural stiffness, light transmittance, and the appearance of natural fiber, it functions as a self-bearing, translucent space divider. It consists of three shapes of double-curved composite panels made from sisal fiber, linen textile, and soy-protein resin that may be combined to extend the surface in multiple directions. Circular cutouts create multiple possibilities in transparency and light filtering.
As these examples demonstrate, future limitations in resources will not dampen creative thinking. Because of architectural textiles’ unparalleled properties of lightness, adaptability, multi-functionality, and resource effectiveness, fabric structures will play a critical role in the future physical environment.