The concept of building using 3D printing processes now even conquers the air: from the model of bees, swallows and others, scientists have developed flying 3D printers that can construct or repair structures in a sophisticated way. Scientists say that in the future, 3D printed drones could be used in hard-to-reach or dangerous places – such as tall buildings or disaster areas.
Instead of bricks, structures are gradually built out of cement layers: 3D printing is also becoming increasingly important in the construction industry. Both on site and in the factory, stationary or mobile robot systems already print components for use in construction projects. Thanks to special machines, even whole houses can now be built using the 3D printing process. However, these systems need to be larger than the structure to be erected, limiting their potential use. On the other hand, 3D printing masters in Nature are much more flexible: bees, swallows and the like can fly to their construction sites to gradually build complex structures from superimposed layers of material.
On the example of bees and what
Scientists led by Ketao Zhang from Imperial College London were inspired by these natural models during their development: they developed the concept of collaborative flying robots that enables the use of 3D printing technology in the air. Known as “Aerial Additive Manufacturing” (Aerial-AM), the system consists of two units: “BuilDrones”, which apply the construction material at intended locations during flight, and “ScanDrones”, which control the process. They continually record BuildDrones progress and determine the next steps in production. Both units operate autonomously, but the human also monitors the process and can make adjustments if necessary based on the information provided by the drones.
However, combining 3D printing technology with a flying robot was a difficult task. One of the biggest challenges was achieving precision when printing in hover mode. To build a stable structure, the cement layers must be applied exactly one on top of the other. However, drones tend to drift slightly when hovering – especially with outdoor air movement. Therefore, scientists developed a printhead attached to the drone with a sophisticated suspension. The system can compensate for slight disturbing aircraft movements during the printing process.
Precision construction work in hover
In this way, precise application of the printing material with millimeter accuracy can be guaranteed, the researchers say. It is applied in the form of a sausage and then hardens. After the BuilDrone have applied the contents of their warehouse, they fly to the stockpile to provide supplies – much like a bee acquiring new building material to build a honeycomb. The team has also developed special building materials that seem to fit their concept particularly well. For demonstration purposes, scientists used their 3D printing drones to successfully build a cylinder approximately two meters high, made of 72 layers of foam, and a cylinder 18 centimeters high, made of 28 layers of specially formulated cement-like material.
“At least in the laboratory, we have already shown that our drones can work autonomously to erect and repair buildings,” says senior author Mirko Kovac of Imperial College and Swiss Federal Laboratories for Materials Science and Technology Empa in Dübendorf. The results seem promising for application in construction practice. A particular advantage of the concept is its mobility. “This scalable solution can facilitate construction and repair in hard-to-reach places,” says Kovac. For example, drones can be used in disaster areas or mountain formations. Building structures could also be erected or repaired at dizzying heights without scaffolding. Scientists believe their technology can, in some cases, provide cost savings and less risk compared to traditional methods. Together with construction companies, they now want to further explore possible applications of the system and further develop the process.
Source: Imperial College London, Federal Materials Testing and Research Institute Empa, Article: Nature, doi: 10.1038 / s41586-022-05247-2
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