[Image above] Credit: Nature Video, YouTube
As we’ve noted numerous times on CTT, one benefit of additive manufacturing is the ability to fabricate complex shapes that are difficult to achieve using subtractive methods. But to realize such precision, 3D-printing equipment is generally rooted tightly in place so each layer can be deposited in the desired location. As such, using additive manufacturing to repair objects in difficult-to-access locations, such as at the top of tall buildings, is not convenient because the equipment cannot be transported there easily.
A new technology developed by an international research team would make such repairs not only feasible but desirable.
The team, co-led by drone expert Mirko Kovac of Empa and Imperial College London and autonomous manufacturing researcher Robert Stuart-Smith of University College London and University of Pennsylvania, developed a swarm of cooperative, 3D-printing drones that can print materials for building or repairing structures while flying.
The system, called Aerial Additive Manufacturing (Aerial-AM), features two types of drones: BuilDrones, which deposit the materials, and quality-control ScanDrones, which measure the BuilDrones’ output and inform their next manufacturing steps. The drones are fully autonomous in flight, but a human controller can monitor progress and intervene if necessary.
In a paper published in Nature, the researchers demonstrated proof-of-concept prints, including a 2.05-meter-high cylinder (72 layers) made of a rapid-curing insulation foam material and a 0.18-meter-high cylinder (28 layers) made of a structural pseudoplastic cementitious material. They developed the latter material themselves so the drones would remain light enough to take flight even while carrying the printing material.
The drones took 300 seconds per layer to construct the cement-like cylinder, or 2.3 hours in total. In an interview with The Daily Beast, Stuart-Smith says the drones will get faster and more efficient as the technology is refined, particularly when testing begins outdoors with larger, more powerful drones.
The researchers also simulated builds of cylinders and domes with groups of three and more drones, using beams of light instead of physical materials and taking time-lapse images of the results, to demonstrate how the system could print larger structures.
An Empa press release states the researchers plan to work with construction companies to validate the solutions and provide repair and manufacturing capabilities.
See the drones in action in the video below.