Once the preserve of automotive and engineering industries, robotics is a burgeoning area of research and development in architectural production. The building industry has used robotics since the late 1970s but usually to facilitate construction operations rather than for fabrication. This situation has been transformed, predominantly through the pioneering work of a few architects and researchers who are investigating the application of ‘articulated robots’ for innovative design. These robots are capable of complex procedures and, in contrast to other digital fabrication methods, which are relatively fixed owing to the position of the machine bed or the equipment’s own dimensional constraints, offer considerable flexibility. This flexibility is born of the robot’s ability to work in a non-cubic space, self-referencing its position in relation to an object. In addition, the robot’s ‘hand’, also referred to as the ‘end effecter’, may incorporate an array of tools and be programmed to accomplish very specific, sophisticated actions. Since robots may be manufactured to the designer’s or end user’s precise requirements, they have an almost unlimited number of applications from material handling to loading and unloading of machines, to arc and spot welding. They can also have lasers mounted on them to facilitate a number of tasks, are available in different types – including gantry, four- and six-axis, cleanroom, heat-resistant, and Selective Compliant Assembly (or Articulated) Robot Arm or SCARA robots that are ideal for confined operations – and, in the case of standard or shelf-mounted robots and heavy-duty versions, can be fixed to the floor or ceiling. Moreover, the modular structure of most robots enables them to be easily and quickly reconfigured for different operations. There are of course drawbacks to such technology – principally the fact that robots are not easy machines to use owing to their kinematics, and this is the main reason their greatest application in the automotive industry is for single, repetitive tasks and not complex, multiple operations. Robotics also requires particular ergonomics and specifications that may be hazardous to users. The manufacturers provide guidance for health and safety procedures, correct mounting, and maximum carrying capacity or payload of the robots. These issues may prove prohibitive when considering such industrial processes to be integrated into the fabrication of architectural designs. However, as an emerging mode of translating data to fabricate cutting-edge and highly complex designs, robotics provides fertile ground for greater exploration.
Robots may be used to carry out a sophisticated series of manoeuvres and operations, as illustrated in this example where a robotic arm has lifted, swung, then held a foam block in relation to a hot-wire cutter to enable a precise geometry to be cut from it.
Case study Robotic experimentation and materiality
Supermanoeuvre and Matter Design – wavePavilion, 2010, and additive foam research, 2009.
Dave Pigram of Supermanoeuvre and Wes McGee of Matter Design have collaborated on developing custom software for robotic fabrication for several years. Key to their explorations is the consideration of the material as an intelligent third party in the design process. By using algorithms to directly control the fabrication processes and subsequently reintegrating data from the material’s behaviour, they have developed a feedback loop between the digital and material.
While developing robotic fabrication protocols for the wavePavilion, by macdowell. tomova, the architects designed and produced a CNC rod-bending device that operates in conjunction with a multi-use 7-axis robotic arm to shape the components of the pavilion. A custom script was written to translate the design data from the RhinoScript code into a series of procedures for the robot and the bender.
A AND B The complexity of the bespoke manufacturing process is apparent in the custom-fabricated robotic bending system coupling robotic positioning with an external-axis bender.
C Once the tooling of this process is developed, the fabrication of components may be implemented by cold forming to bend the steel tubes.
D The completed pavilion constructed at the University of Michigan’s Taubman College of Architecture and Urban Planning, fabricated from more than 1km of 6.35mm (1/4 in) diameter steel rod and over 6m x 9m and 4.5m high.
E TO H For this research project, the final product of additive foam lends itself to further refinement through the process of milling. After the rough formal volume is achieved, a second pass using a spindle tool allows the subtractive smoothing of the surface. This hybridized process is a method capable of realizing almost any conceivable form.
I TO M The applications for additive foam in architecture are potentially broad: as a mode of realizing large scale form at a reasonable cost, but also as a means to create another end, whereby the foam might be used as temporary formwork in the fabrication and construction sequencing of another production.
This research into additive foam to make full-size polyethelene foam wall prototypes seeks to respond to the need to consider material and structural logic in relation to form and scale. By integrating robotics to behave as large 3D printers, the potential of the additive process at the scale of building becomes evident. The process is begun by the robot translating a target form into a series of volumetric continuous lines which are machine paths informed by the feed rate and volume of the foam. To be successful, the process has to understand and account for the foam’s expansion rate otherwise it is predisposed to distort unpredictably and even collapse. While typical 3D printing machines employ only 3 axes of motion, using a multi-axis robot refines the process of sequential layering by allowing the addition of foam from any angle. This lends more flexibility to the staging of additions and because the foam is more capable of withstanding bending and tension, a better choreographed and considered formal development is possible. The process suggests material mutability, where it might be adapted to other material methods that incur a material phase shift from liquid to solid such as concrete pouring.
Case study Robotic fabrication of architecture
Gramazio & Kohler – Façade of Gantenbein Vineyard, Fläsch, 2006.
This project developed a non-standardized brick façade for an extension to a Swiss vineyard. The initial design proposed a simple concrete skeleton filled with bricks: the masonry acts as a temperature buffer and filters sunlight to the sensitive fermentation room behind. The bricks are offset, so that daylight penetrates the hall through the gaps between them; direct sunlight is excluded. Polycarbonate panels are mounted inside to protect against wind. On the upper floor, the bricks form the roof-terrace balustrade.
The robotic production method, developed at ETH Zurich, enabled the designers to lay all 20,000 bricks precisely according to programmed parameters – at the required angle and exact, prescribed intervals. This gave each wall the desired light and air permeability, while creating a pattern that covers the entire building. According to the angle at which they are set, the individual bricks reflect light differently and thus take on varying degrees of lightness. Similarly to pixels on a computer screen, they constitute a distinctive image and thus communicate the vineyard’s identity. Here, however, there is a dramatic play between plasticity, depth and colour, dependent on the viewer’s position and the angle of the sun.
A To create the façade, a generative design process was developed, interpreting the frame construction as a ‘basket’ and filling it with abstract, oversized ‘grapes’ of varying diameters. Gravity was digitally simulated to make the grapes fall into this virtual basket until closely packed.
B The result was then viewed from all sides, and the digital image data transferred to the rotation of the individual bricks. However, the architectural implications of this brick façade are more elaborate and diverse than those of a two-dimensional image.
C Robotic production of the wall elements required a complex series of movements to facilitate the correct geometry of each panel.
D In addition to arranging the units the robot also applied bonding agent to each brick in the 400m2 façade, according to an automated process developed by the designers to accelerate the manufacturing process. Because each brick has a different rotation, every one had a different and unique overlap with the brick below and above.
E Once the bonding agent had been applied, the bricks were assembled, with the programmed data informing the robot’s manoeuvres. Load tests performed on the first manufactured elements revealed that the bonding agent was so structurally effective that the reinforcement normally required for conventional prefabricated walls was unnecessary.
F Because construction was already quite advanced, there was only three months before assembly on site. This made manufacturing the 72 façade elements a challenge, both technologically and time-wise. As the robot could be driven directly by the design data, without the need for additional drawings, the design of the façade was developed up to the last minute before starting production.
G The wall elements were manufactured as a pilot project in research facilities at ETH Zurich, transported by lorry to the construction site and craned into place.
H Installation of the wall panels within the concrete frame on site.
I Internal façade effect, illustrating the ‘grapes’ and their composition along the wall length.
J External appearance, showing the fine grain and variations of the pattern produced across the individually positioned bricks.
K Joints between the bricks were left open to create transparency and allow daylight to filter inside. To make the pattern discernible from the interior, the bricks were laid as close together as possible so that the gap at full deflection was nearly closed. This produced a maximum contrast between open and closed joints, and allowed light to model the interior walls poetically.
L To the human eye, able to detect the finest difference in colour and lightness, the subtle deflection of the bricks creates an appearance and plasticity that constantly changes along with the movement of the observer and the sun over the course of the day.
