Aerial-AM drones take cues from bees to 3D print structures

Researchers at Imperial College London and Empa have led the development of Aerial-AM (Aerial Additive Manufacturing), a fleet of bee-inspired 3D printers that build and repair structures while airborne.

Aerial AM custom buildDrone with a delta-arm manipulator
Aerial AM custom buildDrone with a delta-arm manipulator - Imperial College London Aerial Robotics Laboratory/UCL/Bath University

The lab tested technology could be used for manufacturing and building in difficult-to-access or dangerous locations including tall buildings or help with post-disaster relief construction, the researchers said. Their findings are published in Nature.

Both on-site and in the factory, static and mobile robots are already printing materials for use in construction projects. This new approach to 3D printing employs drones that use collective building methods inspired by natural builders like bees and wasps who collaboratively create large, intricate structures.  

The drones in the Aerial-AM fleet are said to work co-operatively from a single blueprint, adapting their techniques as they go. They are fully autonomous while flying but monitored by a human controller who checks progress and intervenes if necessary, based on information provided by the drones. 

In a statement, lead author Professor Kovac, of Imperial’s Department of Aeronautics and Empa’s Materials and Technology Center of Robotics said: “We’ve proved that drones can work autonomously and in tandem to construct and repair buildings, at least in the lab. Our solution is scalable and could help us to construct and repair building in difficult-to-reach areas in the future.”

According to Imperial, Aerial-AM uses a 3D printing and path-planning framework to help the drones adapt to variations in geometry of the structure as a build progresses. The fleet consists of BuilDrones, which deposit materials during flight, and quality controlling ScanDrones that continually measure the BuilDrones’ output and inform their next manufacturing steps. 

To test the concept, the researchers developed four bespoke cementitious mixtures for the drones to build with.  

Throughout the build, the drones assessed the printed geometry in real time and adapted their behaviour to ensure they met the build specifications, with a claimed manufacturing accuracy of five millimetres.  

The proof-of-concept prints included a 2.05m high cylinder (72 layers) with a polyurethane-based foam material, and an 18cm high cylinder (28 layers) with a custom-designed structural cementitious material. 

Next, the researchers will work with construction companies to validate the solutions and provide repair and manufacturing capabilities.  

Professor Kovac said: “We believe our fleet of drones could help reduce the costs and risks of construction in the future, compared to traditional manual methods.”

Co-investigators include Robert Stuart-Smith, Stefan Leutenegger, Vijay Pawar, Richard Ball, Chris Williams and Paul Shepherd, and their research teams at UCL, Bath University, University of Pennsylvania, Queen Mary University of London, and Technical University of Munich (TUM). It was launched by Assistant Professor Stuart-Smith at UCL and University of Pennsylvania and Professor Kovac at Imperial and Empa (the Swiss Federal Laboratories of Materials Science and Technology) after a pilot research collaboration and award for a demonstration on pipeline repair.

This work was funded by EPSRC, the Royal Society, the European Commission’s Horizon 2020 Programme, Royal Thai Government Scholarship and a Bath University Scholarship. The project is also supported by Industrial Partners Skanska, Ultimaker, Buro Happold, and BRE.