In a workshop south-east of Stuttgart’s city centre, builders can fly. Here, programmed by students at Stuttgart University’s Institute for Computational Design (ICD), drones buzz around like purposeful bees, fetching and carrying long threads of carbon fibre spun by a robot in the middle of the room. Bit by bit, and without the help of a single human hand, the drones shape these strands into a structure.
The workshop is run by Achim Menges, a German architect and the founder of the ICD. He is at the forefront of the rapidly evolving field of robotic architecture, in which robots make not only the components of buildings but also assemble the buildings themselves. This approach offers two advantages. The first is that it saves money and time. This year in Vienna, Coop Himmelblau, an Austrian architectural firm, will use robots to help build a new hotel tower, the machines lifting and welding the panels that form the building’s exterior into place. Wolf D. Prix, the architect behind the project, estimates that robots could reduce construction times and manpower by as much as 90%, which gives architects more freedom to create.
In California, Ron Culver and Joseph Sarafian have developed an unlikely method of making intricate structures out of concrete using robots and Lycra. Traditionally, concrete is formed using hard moulds; for each different shape you want to generate you need a different mould. But in Culver’s and Sarafian’s system, the concrete is poured into Lycra sacks stretched by robotic arms into any number of different shapes. Once set, the pieces are bound together using 3D-printed joints. The technique allows them to add complexity without cost.
The second advantage is that robots open up entirely new methods of design and fabrication. In Zurich, Matthias Kohler and Fabio Gramazio, who in October 2016 opened a new robotics laboratory, have been demonstrating how cheap, recyclable structures can be built from low-grade material without mortar or adhesive of any kind. Their Rock Print project, developed with the Self-Assembly Lab at the Massachusetts Institute of Technology, is a tower of glass pebbles held together by nothing more than thread woven by a robot. The machine, guided by an algorithm, lays down the thread in a pattern so precise it would be unachievable by hand, over which the pebbles are then poured. This is repeated layer by layer until a tower emerges, bound together by nothing but string. Its structural integrity has more in common with lasagne than with a conventional building. It’s a process that might one day be used to build quickly in emergencies.
Menges is employing robots to draw on the beauty and economy of nature. Working with biologists at the University of Tübingen his team analysed the fibrous structure of the wing cases of potato beetles. Then, with engineers in Stuttgart, he developed a robot which wove together threads of transparent glass fibre and black carbon fibre to mimic that structure. At the Victoria and Albert Museum in London in 2016, this method was used to create a series of hexagonal canopies which gradually came together to form a fan of lightweight vaults spreading around the ornamental pond in the museum’s central courtyard. By combining that robot with the drones at his workshop, these fibres can be carried across voids to create bridges, as though created by a mechanical spider.
What robots weave they can unweave. “Future buildings constructed on these principles”, he says, “could be taken down, recycled and re-assembled in new forms. We could have buildings that grow when we need them to, and disappear when redundant without wasting material and without messy and environmentally harmful demolition.”
He is also using robots to exploit how materials behave. His HygroScope, an exquisite, vault-like composition made of maple, was inspired by the way spruce cones open and close. He harnessed the mechanical potential inherent in wood itself: how it changes shape as it absorbs and exudes moisture. Precisely how a piece of wood responds is governed by its grain, so Menges used robots to scan and then mill more than 4,000 uniquely calibrated parts. The resulting structure featured apertures made of thin wooden flaps which curled open or closed uniformly, without any mechanical assistance, as the humidity in the air changed.
In 2014, his team built a pavilion out of beech that mimicked the strong but lightweight form of sea-urchin shells. Robots made 243 geometrically unique panels, just 50mm thick, including the 7,600 joints holding them together. “This gave us 605 cubic metres of space from just 12 cubic metres of local hardwood,” he says. Just as environmentalists talk about food miles, he talks about “building miles”. “We can use locally sourced materials economically for advanced design. There’s no need to ship steel from half way around the world.”
What next for this intriguing revolution? Maria Yablonina, born in Siberia and trained as an architect in Moscow, has been developing mobile robots in Stuttgart for her doctoral thesis. “One can imagine a building site,” she says, “inhabited by multiple robots – a family of robots – working together.” The paradox is that it has taken computers and machines to do what spiders and pine cones have been doing since long before there were architects.