Researchers from the Swiss Federal Laboratories for Materials Science and Technology (Empa) and EPFL have published a study exploring the potential of aerial robots—commonly referred to as construction drones—for use in autonomous building and repair processes. The study, featured in Science Robotics, presents Aerial Additive Manufacturing (Aerial AM) as a future-oriented construction method designed to complement existing ground-based systems, especially in areas that are hard to reach or unsafe for conventional equipment.

Extending the Reach of Construction
Unlike traditional robotic systems, which are often heavy, permanently installed, and limited to accessible terrain, aerial robots are lightweight and mobile. These characteristics make them suitable for operations in mountainous regions, on rooftops, in disaster zones, and even in extraterrestrial environments. Their deployment does not require a fixed construction site, and they can be used in swarms, offering flexibility and scalability. Potential applications include the delivery and assembly of emergency shelters in post-disaster areas, and the autonomous repair of structures such as high-rise facades and bridges, where conventional access is challenging or impossible.

Construction Methods in the Air
The study outlines three main approaches within Aerial AM: constructing structures with modular components (Discrete Aerial AM), creating tensile structures using linear elements (Tensile Aerial AM), and depositing materials layer-by-layer in a continuous manner (Continuous Aerial AM). Each approach requires materials that are lightweight, durable, and compatible with in-flight processing, highlighting a clear demand for innovation in biobased, recyclable, or otherwise sustainable materials suited for airborne application.

Integrating Robotics, Materials, and Architecture
One of the primary challenges of Aerial AM is the need for coordinated advances across multiple disciplines. High-precision drone control must be matched with the development of materials that can be reliably transported and applied in mid-air, as well as architectural designs adapted to the precision and payload constraints of aerial systems. The study introduces a five-level autonomy framework for construction drones, ranging from basic route-following to fully autonomous systems capable of analysing the environment, identifying errors, and adapting the construction process in real time.

Limitations and Hybrid Approaches
While current aerial systems face limitations, particularly in terms of energy consumption—which is estimated to be eight to ten times higher than that of ground-based machines—and payload capacity, the researchers propose a hybrid model. In this model, conventional systems are responsible for constructing the lower portions of a structure, while drones handle higher or less accessible areas, bringing their specific advantages into play.

DroneHub: Bridging Research and Real-World Application
Testing and development of these technologies is taking place at the new DroneHub, located within Empa’s NEST innovation building. This facility serves as a bridge between laboratory research and industrial application, allowing for real-world testing and further development. DroneHub also supports a joint professorship between Empa and Imperial College London, aimed at advancing the field of sustainability robotics. Initial field trials of the drone-based construction systems are scheduled to begin later this year.

Implications for Sustainable and Adaptive Design
This research opens new opportunities for sustainable and decentralised construction methods, particularly in contexts where flexibility, rapid deployment, and reduced logistical demands are essential. It also raises important questions for material designers and architects about how building components can be reimagined for airborne application and autonomous assembly.

Source: Empa