Heat-resistant drones can reach and map burning buildings and forest fires

By Hayley Dunning and Caroline Brogan

The drone prototype, called the FireDrone, could be sent into a burning building or forest to assess the hazard and provide important first-hand data of the hazard zone. Data will then be sent to first responders to help inform their emergency response.

The drone is made of a new thermal airgel insulation material and has a built-in cooling system to help it withstand temperatures of up to 200°C for ten minutes. Currently at the prototype stage, researchers believe the FireDrone could eventually be used to reach fires for people and additional hazards to support firefighting.

Principal Investigator Professor Mirko KovacDirector of Air Robotics Laboratory at Imperial College London and Head Sustainability Robotics Laboratory di Empa, said: “Until they enter the danger zone, firefighters cannot be sure what or who they will find, and what challenges they will face.

“FireDrones can be dispatched in advance to gather critical information so responders can prepare appropriately to keep themselves safe and potentially save more lives.”

– Professor Mirko Kovac

Animal-inspired pioneers

Drones are already used remotely in firefighting to take aerial footage, lift fire hoses onto skyscrapers, or drop fire retardants in remote areas to slow the spread of wildfires. However, current drones developed for firefighting cannot fly any closer lest their frames melt and their electronics fail.

Based on interviews with firefighters, researchers know closer drones can help prepare first responders to enter burning buildings or forests. Drones equipped with cameras and carbon dioxide (CO2) sensors, for example, can provide important information about fire layout and composition.

They look to animals that live in extreme temperatures for inspiration, such as penguins, arctic foxes and spittlebugs. All of these have a suitable layer of blubber, fur, or produce their own layer of thermoregulating material that allows them to thrive in extreme conditions.

Inside the drone, exposing the airgel layer. Credit: Empa

To build the drone, they created a protective structural shell made of lightweight super-insulating materials such as polyimide aerogel, and glass fiber. They coated it with light-reflective aluminum to reflect heat. Super-insulation prevents the material from shrinking and the pore structure from degrading after exposure to high temperatures.

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

Extreme temperature

They tested the drone in a temperature-controlled room and flew it near a fire at a firefighting training center. They hope their further work to scale down and add more sensors to drones can lead to their application in real-life firefighting missions and help save lives.

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

FireDrone tested on a glacier

Although the FireDrone is still in its 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 industry stakeholders and partners.

Professor Kovac said: “The application of drones is often limited by environmental factors such as temperature. We demonstrated a way to address this and are confident our findings will help unleash the power of drones in the future for extreme environments.”

“Deploying robots in extreme environments provides great benefits for reducing risks to human life, and who better to see than animals who have developed their own ways to adapt to these extremes using inspiration from how animals stay cool in hot weather.”

• PAPER – FireDrone: Multi-Environment Agnostic Thermal 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.