Heat-resistant drones to support firefighters

Swiss fire brigades were called out more than 15,000 times last year to fight fires. Because temperatures in a burning building can reach a deadly 1,000 degrees Celsius, any unnecessary risk must be avoided. A new flying robot could help in such operations: experts from Empa and Imperial College London are currently developing a heat-resistant drone that can provide initial data from the source of danger.

In such situations, drones equipped with cameras and CO2 sensors could provide important information about the distribution of fire sources, as well as unexpected hazards or trapped people. With the information gained in this way, emergency teams could better adapt their strategy to the situation before entering a burning building, say the creators of the new drone in a press release.

Drones are already being used to fight fires, to take aerial photos of fires, to lift fire hoses onto skyscrapers or to drop extinguishing agents in remote areas, for example to contain the spread of forest fires. However, all this is currently only possible if the drone is far enough away from the source of the fire. Because if flames are too close, the frame melts and the electronics give up.

The Swiss researchers therefore set out to find an insulation material that does not melt even at high temperatures. They found inspiration for this in nature, in animals such as the penguin and arctic fox, whose habitats are characterised by extreme temperatures. They all have corresponding layers of fat, fur or the body's own protective layers of thermoregulating material, which the animals produce themselves and which enable them to survive under extreme conditions.

They found what they were looking for in an aerogel, an ultralight material that consists almost entirely of air-filled pores enclosed in a hint of polymer substance. As Empa writes in its press release, polyimide aerogels are also being researched by NASA, among other things as insulation for space suits.

The prototype of the FireDrone, which is around 50 centimetres tall, was convincing in initial tests in Empa's flight arena in Dübendorf and succeeded in tests under real conditions. The flight characteristics and controllability are excellent, even with an aerogel insulation jacket and an additional built-in cooling system as well as an aluminium covering that reflects the heat, according to the press release.

According to Empa, the FireDrone can also be used in extremely cold environments, such as in polar regions and on glaciers. The team has already tested the drone in a glacier tunnel in Switzerland to find out how the system behaves at very low temperatures. Talks are under way with potential industrial partners to further develop the prototype.