In the same way our immune system protects the human body, drones will in future maintain our buildings and infrastructure. They will detect damage and carry out repair and maintenance work on their own. This is how drone researcher Mirko Kovac paints the picture when he talks about his vision for the interaction between autonomous flying robots and our built environment. The comparison with biology and the human body is no coincidence: As head of Empa's Sustainability Robotics Lab and director of the Aerial Robotics Lab at Imperial College London, Kovac and his team draw inspiration from nature for their research. This results in drones that dive in and out of the water like waterfowl and take to the skies in seconds, or drones that attach themselves to walls and ceilings and rappel down thin threads like spiders. Or entire swarms of drones are being created, inspired by a colony of bees, that can build in a division of labor while flying and with 3D printing processes. At the same time, researchers are working on bio-hybrid flying robots that biodegrade in nature after their work is done, leaving no traces behind.

Such and other drone systems are developed and tested today in the flight arenas at Empa in Dübendorf and at Imperial College London. To complement this and to make the development conditions even more realistic, an aviary is now to be built on the NEST research and innovation building that can be used as a permanent outdoor test environment for various applications. "With the DroneHub at NEST, we also want to better understand the needs of industry in particular and incorporate them into our research," explains Kovac, and therefore explicitly invites interested companies to collaborate. Cooperations with strong partners are the premise for a successful realization.

The DroneHub is a kind of cage with a height of up to 11 meters and an area of 90 square meters. It consists of a tube construction and a mesh and will be located on the top platform of NEST – between the two existing units DFAB HOUSE and HiLo. When completed, the DroneHub will provide test environments for three research fields: On the north side, an experimental facade dominates the picture. The wall is fitted with interchangeable elements with different surfaces and is used to develop drones that can carry out inspection and repair work in the vertical. This includes aerial 3D printing processes – in technical jargon, aerial additive manufacturing. "The drones can detect and repair cracks, for example, without the need for elaborate scaffolding or endangering the safety of people," Kovac says.

Having drones on standby at all times increases the speed, at which damage can be repaired – minimizing potential infrastructure outages. "This can be very relevant, especially for energy facilities such as wind turbines or dams," says the drone expert. The fact that the DroneHub is an open air facility, but at the same time embedded in a building structure, means that realistic conditions prevail with regard to wind and weather and the resulting turbulences.

The second research field focuses on the interaction between drones and nature. Today's climate research relies on sensor and monitoring data from the environment. "Drones are perfect data providers – especially in impassable and wide-ranging areas. They can place targeted sensors in nature and read the data with regular flights," explains Mirko Kovac. The important thing is that the sensor and drone systems themselves have no adverse impact on the environment. And that is precisely what the DroneHub is all about: In a naturally designed environment with trees and forest floor, tests can be carried out with biodegradable drone and sensor materials. Part of this biosphere will also serve as a greenhouse for bio-hybrid robot structures – for example, for components for drones made of renewable and biodegradable materials.

For the third research area, the DroneHub is to be supplemented with interfaces to the outside world. "If we imagine a future, in which drones are naturally integrated into everyday urban life and robots and humans coexist, then we need rules and technological standards for this," explains Kovac. This starts, for example, with the landing sites on or near buildings that drones are to approach autonomously – or with charging stations, at which transport drones independently refuel energy for the next flight. In the DroneHub, the researchers will develop and establish technical guidelines for such interfaces between buildings and flying robots – and help to ensure that a coexistence of man and machine does not remain science fiction.

Empa's drone research has strong national and international links – including collaborations with EPFL and Imperial College London. In addition, drone activities will also develop at the nearby Zurich Innovation Park in the coming years. Funded by the cantonal digitalization initiative, a test infrastructure for autonomous flight and vehicles is being created under the leadership of the University of Zurich, the Zurich University of Applied Sciences (ZHAW) and the Zurich University of the Arts (ZHdK). The long-term goal of the recently launched project, called LINA, is to establish a certification body for commercial drones. Empa researchers are in exchange with LINA to promote complementary activities and make the Greater Zurich area a true hotspot for Swiss drone research.

Empa researchers are developing drones for all aspects of the environment, represented as the four "elements" of fire, water, earth and air. Illustration: Empa