Synthetic-biology-based approaches to design practices, which have a material engagement with design and engineering practices, propose a new set of conditions in which architectures can alter their characteristics to suit changing environmental conditions. Living materials raise the possibility that buildings can make a positive impact on their local surroundings by performing remedial functions, that the construction of architecture could actually heal a stressed environment, for example, by removing toxins or fixing greenhouse gases. These new technologies could be on building exteriors, which present a managed interface with the environment.
Responsive architectures that are sensitive to their local environment can revitalize cities and equip communities with the ability to deal with and recover from radical disturbances in their surroundings, such as a natural disaster. Indeed, all cities should be designed with environmental crises in mind, whether they have reached the proportions of a megacity or not. Densely populated areas need to be considered potential disaster zones, where living spaces are at risk from the accumulation of toxic waste and from physical damage as a consequence of our unstable Earth. Given the present environmental challenges and worldwide population growth, fundamental changes in the expectations of buildings must be considered globally. This is a more urgent and radical requirement than current notions of sustainable development that pander to industrial developers; it promotes and demands an immediate rethinking of the way that we build our homes and cities. The strategic use of these new materials, woven into the substance of the urban landscape on building surfaces and into structural fabrics, provides an opportunity for buildings to actively participate in environmental challenges.
Architectural performance is currently optimized under stable conditions, but its suitability to any given environment will change when even minor variations occur, such as changes in the weather. Current predictions suggest that a worldwide trend toward increasingly variable weather patterns can be expected over the course of the century. The inflexibility of today’s buildings to deal with daily fluctuations, where walkways regularly flood after a moderate downpour in places such as New York, offers a telling snapshot of how unprepared cities are for even more challenging environmental changes like rises in sea level. In general, radical changes in infrastructure are contemplated following, rather than in anticipation of, a natural disaster. For example, Japan’s world leadership in disaster-prevention technologies has been prompted by a century of devastating earthquakes.
Synthetic-biology approaches change our expectations of architecture. Rather than being inert, buildings could respond to the seasons as our parks and gardens do, with living coatings adapting to the availability of more or less wind, sunlight and water. Protocell-based coatings offer not only the capacity for a unique growth of materials but also potential applications in "healing" "broken" buildings, by which molecular interactions detect and deposit material into stress fractures to form "scar tissue" at the microscale.
In the right contexts these kinds of surfaces could stabilize unsafe buildings such as those in Sendai and the surrounding region, which was so recently devastated by seismic activity. These new materials do not replace existing forms of architectural practice but are symbiotic with them and ultimately equip existing buildings with the capacity to engage in a literal struggle for survival so they can co-evolve with their surroundings. These approaches can produce a range of building types that are uniquely tuned to the particular niche conditions of an environment to create a range of responsive architectural experiences.
Novel materials may change the "fertility" of an urban environment. Cities could be active sites of resource production rather than sumps of consumption. Living materials could be used on the roofs of our cities, like solar panels, to harvest carbon dioxide and produce energy in the form of liquid fuel rather than electricity, rather as the green leaves of plants do, as an alternative to cutting down trees or burning fossil fuels.
Places such as Yemen, the saltbush country in Australia, and the Colorado River in the United States, which are all experiencing effects of the worldwide water crisis, need buildings that enable communities to conserve and recycle water. Living materials could function as an integral part of the recycling of domestic water supplies, so that waste could be filtered within the building fabric in a similar way to how soils purify water. Protocell technology and synthetic-biology-based techniques also raise the possibility of a hygroscopic architecture that retains and processes water after absorbing it as dew in the morning, or during a rainfall, to provide readily available sources for human consumption. Excess water could be channeled into reservoirs within the fabric of a building rather than tipped as waste runoff into drains, or used to create clouds of moisture-containing minerals that could precipitate as carbon-dioxide-fixing rain. Traditional materials that are stressed by water could possess paradoxical properties when used in combination with living technologies and may, in fact, blossom in the presence of water. They could tolerate water excesses and manage water shortages during droughts.
Designer chemistries could also produce new functionality within bioscaffolding coats such as resins that are applied to building facades. There, environmental triggers could cause a species of protocell activated by moisture to produce pockets of gas such as carbon dioxide, which would create reversibly spongy matrixes that allowed materials to float in wet conditions and return to a stronger, unexpanded state on drying. Such novel building properties could change the appearance of the built environment during times of rainfall; walkways, for example, could be raised by the increased turgor and swelling of materials. When water was extracted from the materials by usage, convection, and evaporation, the buildings would dry out and return to a less fleshy, more familiar appearance.
Protocell technologies function in a dynamic and useful way in conditions that are hostile to biology. The recent chemical spill from an alumina plant in Ajka in western Hungary--where an avalanche of toxic, flesh-corroding, alkaline, chemical waste burst from a reservoir about 160 kilometers (100 miles) from the capital Budapest--affected an area of 40 square kilometers (15.4 square miles). Seven villages and towns were affected, including Devecser, where the torrent was 2 meters deep. The heavy contamination means that almost an inch of soil has to be removed from the whole of the contaminated region. Even after neutralization of the chemicals, dust from the affected area is likely to pose a cancer risk to residents. This is a situation in which nonbiological protocell technologies could be used to perform remedial functions under conditions that would destroy most natural organisms.
Protocell coatings could be designed to neutralize the effect of the alkali through application to building exteriors once the main spill has been neutralized. Since protocells are active under even very strongly alkaline conditions, they could be used to treat unneutralized alkali that is carried on contaminated dust from the site of the disaster into living spaces. In other toxic situations synthetic biologies, which can tolerate extreme environmental conditions, could also act as remediating display systems to warn residents about the presence of dangerous toxins, especially when these chemicals cannot be smelled or seen, like radioactive waste (for example, genetically modified radioactivity-resistant bacteria could be engineered to express a fluorescent gene in the presence of nuclear waste).
Living technologies may ultimately have the ability to change the fundamental relationship between human development and the environment. This would be a major shift in our building practices that could contribute to our continued survival rather than the destruction of our biosphere. One day, this pastoral role conferred by architecture on the environment may extend to its human inhabitants. We may think of our buildings as domestic guardians that offer robust protection against the consequences of climate change, or the advent of natural disasters.