It's a nightmare scenario. You're on an ambitious mountain hike when you get lost, injured or stranded. The good news is help is finally on the way, but the bad news is it's going to take time to reach you and you're out of food. That's when a buzzing drone comes flying in for a landing. Not only do you get the snacks, medicine or water it's carrying, you can eat the wings to tide you over until the rescue team arrives.

This scenario could become real. A team with the Swiss Federal Institute of Technology, Lausanne (EPFL) has developed a prototype edible drone. The munchable machine is part of a broader project called RoboFood. RoboFood is about investigating edible robots for humans and animals as well as foods that behave like robots.

The team published its work online with the title "Towards edible drones for rescue missions: design and flight of nutritional wings." The study is tackling the problem of getting commercial drones to carry enough of a payload to help people in emergency situations.

The design uses some familiar-looking airplane-like components, but the big difference is that the fixed wing is made from rice cakes and gelatin that together pack 300 calories. IEEE Spectrum spoke with lead author Bokeon Kwak who said the drone "tastes like a crunchy rice crisp cookie with a little touch of raw gelatin." If you're stranded and hungry, it would probably be delicious.   

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To make the wings, the researchers trimmed up round rice cakes using a laser cutter and glued them together with gelatin to create a wing structure that could hold up to flight. The rice is strong, but lightweight and still reasonably nutritious. The drone would be a one-way proposition, but the partially edible nature means there wouldn't be a lot of debris left behind.

The idea of edible drones has been kicking around for years. We met a chocolate quadcopter back in 2014 and a UK aerospace company talked up an edible drone called Pouncer in 2017. It seems Pouncer hasn't made it into production, but the general concept is alive and well with the rice-cake-wing drone.

The edible-drone team intends to investigate ways to make the drone more nutritious and see if it could add more edible components to the design. No matter what you think of rice cakes as a food, in a tough situation, they would be like manna from heaven.