By Hayley Dunning and Caroline Brogan

The prototype drone, called FireDrone, could be sent into burning buildings or woodland to assess hazards and provide crucial first-hand data from danger zones. The data would then be sent to first responders to help inform their emergency response.

The drone is made of a new thermal aerogel insulation material and houses an inbuilt cooling system to help it withstand temperatures of up to 200°C for ten minutes. Currently at prototype stage, the researchers believe FireDrone could eventually be used to scope out fires for people and extra hazards to bolster firefighting.

Principal Investigator Professor Mirko Kovac, Director of the Aerial Robotics Lab at Imperial College London and Head of the Laboratory of Sustainability Robotics at Empa, said: “Until they enter the danger zone, firefighters can’t be certain of what or who they’ll find, and what challenges they’ll encounter.

“FireDrone could be sent in ahead to gather crucial information so that responders can prepare accordingly to keep themselves safe and potentially save more lives.”

– Professor Mirko Kovac

Animal-inspired trailblazers

Drones are already used from afar in firefighting to take aerial footage, hoist fire hoses up skyscrapers, or drop fire retardant in remote areas to slow the spread of wildfires. However, current drones developed for firefighting are unable to fly much closer lest their frames melt and their electronics fail.

Based on interviews with firefighters, the researchers knew drones that could get much closer could help to prepare first responders for entering burning buildings or woodland. Drones equipped with cameras and carbon dioxide (CO2) sensors, for example, could provide crucial information about the layout and composition of fires.

They looked to animals that live in extreme temperatures like the penguin, arctic fox, and spittlebug, for inspiration. All these have appropriate layers of fat, fur, or produce their own layers of thermoregulating material that allow them to thrive in extreme conditions.

Inside the drone, showing the layer of aerogel. Credit: Empa

To build the drone, they created a protective structural shell made of lightweight, thermally super-insulating materials like polyimide aerogel, and glass fibres. They coated this with super-reflecting aluminium to reflect heat. The super-insulation prevents the materials from shrinking and pore structures from degrading after exposure to high temperatures.

Within the protective exoskeleton, they placed the temperature-sensitive components, such as regular and infrared cameras, CO2 sensors, video transmitters, flight controllers, batteries, and radio receivers. They also used the release and evaporation of gas from the CO2 sensors to build a cooling system to keep temperatures down.

Temperature extremes

They tested the drone in temperature-controlled chambers and flew it close to flames at a firefighter training centre. They hope that their further work to miniaturise and add more sensors to the drone might lead to its deployment in real-life firefighting missions and help save lives.

FireDrone can also be used in extreme cold environments, in polar regions and in glaciers. The team has also tested the robot in a glacier tunnel in Switzerland to study how the system behaves in very cold temperatures.

FireDrone tested in a glacier

Although FireDrone is at prototype stage, the researchers say it is a step forward for the development of other drones that can withstand extreme temperatures and the team is now validating the technology with key industrial stakeholders and partners.

Professor Kovac said: “The application of drones is often limited by environmental factors like temperature. We demonstrate a way to overcome this and are convinced our findings will help to unleash the future power of drones for extreme environments”.

“Deploying robots in extreme environments provides great benefits to reducing risks to human lives, and who better to look to than animals that have evolved their own ways of adapting to these extremes using inspirating from how animals keep cool in heat.”

• PAPER – FireDrone: Multi-Environment Thermally Agnostic Aerial Robot.
  David Häusermann, Sam Bodry, Fabian Wiesemüller, Aslan Miriyev, Severin Siegrist, Fan Fu, Sabyasachi Gaan, Matthias M. Koebel, Wim J. Malfait, Shanyu Zhao, and Mirko Kovač. Advanced Intelligent Systems (2023): 2300101.

Credit: Imperial College London

By Caroline Brogan

Imperial researchers have created drones that can attach sensors to trees to monitor environmental and ecological changes in forests.

Sensors for forest monitoring are already used to track changes in temperature, humidity and light, as well as the movements of animals and insects through their habitat. They also help to detect and monitor forest fires and can provide valuable data on how climate change and other human activities are impacting the natural world.

However, placing these sensors can prove difficult in large, tall forests, and climbing trees to place them poses its own risks.

Now, researchers at Imperial College London’s Aerial Robotics Lab have developed drones that can shoot sensor-containing darts onto trees several metres away in cluttered environments like forests. The drones can also place sensors through contact or by perching on tree branches.

Via GIPHY. Credit: Imperial College London

I like to think of them as artificial forest inhabitants who will soon watch over the ecosystem and provide the data we need to protect the environment.

Professor Mirko Kovac, Department of Aeronautics

The researchers hope the drones will be used in future to create networks of sensors to boost data on forest ecosystems, and to track hard-to-navigate biomes like the Amazon rainforest.

Lead researcher Professor Mirko Kovac, Director of the Aerial Robotics Lab from the Department of Aeronautics at Imperial said: “Monitoring forest ecosystems can be difficult, but our drones could deploy whole networks of sensors to boost the amount and precision of environmental and ecological data.

“I like to think of them as artificial forest inhabitants who will soon watch over the ecosystem and provide the data we need to protect the environment.”

The drones are equipped with cameras to help identify suitable targets, and a smart material that changes shape when heated to launch the darts, which then stick to the trees. They can also perch on tree branches like birds to collect data themselves, acting as mobile sensors.

The researchers have tested their drones at the Swiss Federal Laboratories for Materials Science and Technology (EMPA) and on trees at Imperial’s Silwood Park Campus.

Via GIPHY. Credit: Imperial College London

We aim to introduce new design and control strategies to allow drones to effectively operate in forested environments.

Dr Salua Hamaza, Department of Aeronautics

The drones are currently controlled by people: using control units, the researchers watch through the camera lens to select target trees and shoot the darts. The next step is to make the drones autonomous, so that researchers can test how they fare in denser forest environments without human guidance.

Co-author André Farhina, of the Department of Aeronautics, said: “There are plenty of challenges to be addressed before the drones can be regularly used in forests, like achieving a careful balance between human input and automated tasks so that they can be used safely while remaining adaptable to unpredictable environments.”

Co-author Dr Salua Hamaza, also of the Department of Aeronautics, said: “We aim to introduce new design and control strategies to allow drones to effectively operate in forested environments. Exploiting smart mechanisms and new sensing techniques we can off-load the on-board computation, and create platforms that are energy-efficient and better performing.”

• Hamaza, S., Farinha, A., Nguyen, H.N. and Kovac, M., 2020, November. Sensor Delivery in Forests with Aerial Robots: A New Paradigm for Environmental Monitoring. In IEEE IROS Workshop on Perception, Planning and Mobility in Forestry Robotics.
• Nguyen, H.N., Siddall, R., Stephens, B., Navarro-Rubio, A. and Kova?, M., 2019, April. A Passively Adaptive Microspine Grapple for Robust, Controllable Perching. In 2019 2nd IEEE International Conference on Soft Robotics (RoboSoft) (pp. 80-87). IEEE. Video.
• Farinha, A., Zufferey, R., Zheng, P., Armanini, S.F. and Kovac, M., 2020. Unmanned Aerial Sensor Placement for Cluttered Environments. IEEE Robotics and Automation Letters, 5(4), pp.6623-6630. Video.

These works were funded by the EPSRC, ORCA Robotics Hub, EU Horizon 2020, NERC (QMEE CDT), UKAEA with RACE and the Royal Society.