An international research team led by drone expert Mirko Kovac from Empa and Imperial College London has used bees as a model to develop a swarm of cooperative 3D-printing drones. Under human control, these flying robots work in teams to 3D print materials to build or repair structures while they fly, the scientists report in the cover story of the latest issue of Nature.
3D printing is gaining importance 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, developed by Imperial College London and Empa, the Swiss Federal Institute for Materials Science and Technology, uses flying robots called drones that use collective construction methods inspired by natural builders like bees and bees are wasps.
The system, called Aerial Additive Manufacturing (Aerial-AM), involves a fleet of drones working together on a single design.
It consists of BuilDrones that deposit materials during flight and quality control ScanDrones that continuously measure the performance of the BuilDrones and inform their next manufacturing steps.
The researchers say that, unlike alternative methods, in-flight 3D printing opens doors that lead to on-site manufacturing and construction in hard-to-reach or dangerous locations, such as.
The research was led by Professor Mirko Kovac from the Imperial Department of Aeronautics and Empa’s Materials and Technology Center of Robotics.
Professor Kovac said: “We proved the concept that drones can work autonomously and in tandem to construct and repair buildings, at least in the laboratory. This scalable solution could help with construction and repair in hard-to-reach areas such as tall buildings.”
Aerial-AM uses both a 3D printing and path planning framework to allow the drones to adapt to variations in the structure’s geometry as construction progresses.
The drones fly completely autonomously, but there is a human controller in the loop who can monitor progress and intervene if necessary based on information provided by the drones.
Printing 3D geometries
To test the concept, the researchers came up with four cement-like mixes that the drones could build with.
During construction, the drones evaluate the printed geometry in real time and adjust their behavior to ensure they meet build specifications to within five millimeters of manufacturing accuracy.
The proof-of-concept prints included a 2.05-meter cylinder (72 layers) with a polyurethane-based foam material and an 18-centimeter cylinder (28 layers) with a custom cement-like structural material.
The technology offers future opportunities for building and repairing structures in boundless, high or other hard-to-reach places. Next, researchers will work with construction companies to validate the solutions and provide repair and manufacturing capabilities. They believe the technology will offer significant cost savings and reduce access risks compared to traditional manual methods.
The co-investigators include Robert Stuart-Smith, Stefan Leutenegger, Vijay Pawar, Richard Ball, Chris Williams and Paul Shephard, and their research teams at UCL, the University of Bath, the University of Pennsylvania, Queen Mary University and the University of Munich .
This work was funded by the Engineering and Physical Sciences Research Council, part of UKRI. It was created by Assistant Professor Stuart-Smith and Professor Kovac after a pilot research collaboration and an award for a pipeline repair demonstration. The project is also supported by industry partners Skanska, Ultimaker, Burohappold and BRE.