
3D printing is gaining momentum in the construction industry. Both on-site and in the factory, static and mobile robots print materials for use in construction projects, such as steel and concrete structures.
A new approach to 3D printing - led in its development by Imperial College London and Empa, the Swiss Federal Laboratories of Materials Science and Technology - uses flying robots, known as drones, that use collective building methods inspired by natural builders like bees and wasps.
The system, called Aerial Additive Manufacturing (Aerial-AM), involves a fleet of drones working together from a single blueprint.

Title theme: drones based on natural model. Image: Nature
The researchers say that in contrast to alternative methods, in-flight 3D printing unlocks doors that will lead to on-site manufacturing and building in difficult-to-access or dangerous locations such as post-disaster relief construction and tall buildings or infrastructure.
The research was Led by Professor Mirko Kovac of Imperial’s Department of Aeronautics and Empa’s Materials and Technology Center of Robotics.
Professor Kovac said: "We’ve proved the concept that drones can work autonomously and in tandem to construct and repair buildings, at least in the lab. This scalable solution could help construction and repair in difficult-to-reach areas, like tall buildings."

Teamwork: A BuilDrone and a ScanDrone built this approximately two-meter-high ’tower’ of fast-curing foam - layer by layer. Image: University College London
The drones are fully autonomous in flight, but there is a human controller in the loop can monitor progress and intervene if necessary, based on the information provided by the drones.
To test the concept, the researchers developed four cement-like mixtures for the drones to build with.
Throughout the build, the drones assess the printed geometry in real time and adapt their behaviour to ensure they meet the build specifications, with manufacturing accuracy of five millimetres.