In architecture, new materials rarely emerge.
For centuries, wood, masonry and concrete have formed the basis of most structures on Earth.
In the 1880s, the adoption of the steel frame changed architecture forever. Steel allowed architects to design taller buildings with larger windows, giving rise to the skyscrapers that today define the city’s skylines.
Since the Industrial Revolution, building materials have largely been confined to a range of mass-produced items. From steel beams to plywood panels, this standardized kit of parts has guided building design and construction for over 150 years.
This may soon change with the progress of what is called “large-scale additive manufacturing.” Never since the adoption of steel framing has there been a development with so much potential to transform the way buildings are designed and constructed.
Large-scale additive manufacturing, like desktop 3D printing, involves building objects one layer at a time. Whether clay, concrete or plastic, the impression material is extruded in a fluid state and hardens into its final shape.
As director of the Institute of Intelligent Structures at the University of Tennessee, I had the good fortune to work on a series of projects that deploy this new technology.
Although some barriers to the widespread adoption of this technology still exist, I can foresee a future in which buildings are constructed entirely from recycled or site-sourced materials, with shapes inspired by the geometries of nature.
Promising prototypes
Among these is the trillium pavilionan open-air structure printed from recycled materials ABS polymera common plastic used in a wide range of consumer products.
The fine double-curved surfaces of the structure are inspired by the petals of its namesake flower. The project was designed by students, printed by Loci Robotics, and built on the University of Tennessee Research Park at Cherokee Farm in Knoxville.
Other recent examples of large-scale additive manufacturing include keya 450 square foot (41.8 square meter) housing prototype designed by Mario Cucinella Architects and printed in Massa Lombarda, a small town in Italy.
The architects printed Tecla from clay taken from a local river. The unique combination of this inexpensive material and the radial geometry has created an energy efficient alternative housing form.
Back in the States, architecture firm Lake Flato teamed up with building technology company ICON to print exterior concrete walls for a house dubbed “Zero Housein Austin, TX.
The 2,000 square foot (185.8 square meter) home demonstrates the speed and efficiency of 3D-printed concrete, and the structure displays a pleasing contrast between its curvilinear walls and exposed timber frame.
The planning process
Large-scale additive manufacturing involves three areas of knowledge: digital design, digital manufacturing and materials science.
To start, architects create computer models of all the components that will be printed. These designers can then use software to test how the components will respond to structural forces and adjust the components accordingly. These tools can also help the designer understand how to reduce component weight and automate certain design processes, such as smoothing complex geometric intersections, before printing.
A piece of software known as a slicer then translates the computer model into a set of instructions for the 3D printer.
You might assume that 3D printers operate on a relatively small scale – think cell phone cases And toothbrush holder.
But advances in 3D printing technology have allowed hardware seriously evolve. Sometimes printing is done via what is called a gantry-based system – a rectangular frame of sliding rails similar to a desktop 3D printer. More and more, robotic arms are used because of their ability to print in any orientation.
The printing site may also vary. Furniture and small components can be printed in the factory, while entire houses must be printed on site.
A range of materials can be used for large-scale additive manufacturing. Concrete is a popular choice due to its familiarity and durability. Clay is an intriguing alternative because it can be harvested on site – that’s what Tecla’s designers did.
But plastics and polymers might have the widest application. These materials are incredibly versatile and can be formulated to meet a wide range of specific structural and aesthetic requirements. They can also be produced from recycled and organic materials.
Inspired by nature
Because additive manufacturing builds layer by layer, using only the material and energy needed to make a particular component, it’s a much more efficient construction process than “subtractive methodswhich involve cutting off the excess material – think milling a wooden beam out of a tree.
Even common materials like concrete and plastics benefit from 3D printing because there is no need for additional formwork or molds.
Today, most building materials are mass-produced on assembly lines designed to produce the same components. While reducing costs, this process leaves little room for customization.
Since there is no need for tooling, shapes, or dies, large-scale additive manufacturing allows each part to be unique, with no time penalty for increased complexity or customization.
Another interesting feature of large-scale additive manufacturing is the ability to produce complex components with internal voids. This could one day make it possible to print walls with pipes or conduits already in place.
Besides, research is done exploring the possibilities of multi-material 3D printing, a technique that could allow windows, insulation, structural reinforcement – even wiring – to be completely integrated into a single printed component.
One of the aspects of additive manufacturing that excites me the most is how the layer-by-layer construction, with a slow-curing material, mirrors natural processes, like the formation of shells.
This opens windows of opportunity, allowing designers to implement geometries that are difficult to produce with other construction methods, but are common in nature.
Structural frames inspired by the fine structure of bird bonescould create lightweight lattices of tubes, with varying sizes reflecting the forces acting on them. facades that evoke the shapes of plant leaves could be designed to simultaneously shade the building and generate solar energy.
Overcome the learning curve
Despite the many positive aspects of large-scale additive manufacturing, there are a number of barriers to its wider adoption.
Perhaps the biggest to overcome is its novelty. There is a whole infrastructure built around traditional forms of construction like steel, concrete and wood, which include supply chains and building codes. Additionally, the cost of digital fabrication hardware is relatively high, and the specific design skills needed to work with these new materials are not yet widely taught.
For 3D printing in architecture to be more widely adopted, it will need to find its niche. Similar to how word processing helped popularize desktop computersI think it will be a specific application of large-scale additive manufacturing that will lead to its mainstream use.
Perhaps it will be its ability to print very efficient structural frames. I also already see its promise to create unique sculptural facades that can be recycled and reprinted at the end of their useful life.
Either way, it seems likely that a combination of factors will ensure that future buildings will be, in part, 3D printed.
This article is republished from The conversation under Creative Commons license. Read it original article.