Drones that can increase their food payload from 30% to 50% of their mass were described in a publication earlier this month by researchers at the Swiss Federal Institute of Technology in Lausanne.
At the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) conference in Kyoto, it was discussed how drones have proven effective in unmanned transport missions such as the delivery of food and medical supplies to provide people in crises with life-saving nutrition and medication.
Commercial fixed-wing drones, on the other hand, can often only carry 10 to 30 percent of their mass as payload. As a result, some drone components, such as the wings, might be built of food-grade materials, bringing the drone’s mass ratio for transporting food to 50 per cent.
A flight-capable prototype can give 300 kcal and carry a cargo of 80 grams of water. Should the edible drone be left behind in the environment after performing its mission in an emergency circumstance, it will be more biodegradable than its non-edible version.
Due to the multirotor type drones’ dependability when hovering and manoeuvring, some businesses have already started offering drone delivery services to save the cost of delivering small things on the last mile.
Drones can also be used to carry nutrients that will save lives for people in emergencies where ground vehicles have a tough time getting close. As a result, fixed-wing drones have an edge over multirotor drones.
The edible wing has a wingspan of 678 mm because the volume of a fixed-wing drone’s wing often takes up the most space. Conventional materials are used for the remaining structures, including the electronics, actuators, and fuselage.
To prevent bending or material failure during flight, the wing should be strong enough, which favors foam like expanded polypropylene (EPP) as the main structural material for traditional fixed-wing drones.
One of the most promising candidates was a puffed rice cookie, which was formed by applying high pressure to rice grains at a high temperature and was easily machinable by laser cutting, according to rigorous scientific procedures, including Young’s Modulus testing.
A kg of rice cookies has 3870 calories, which is less than other sweets that have more than 5000 calories/kg of chocolate and candy, but their densities are five to eight times more than those of the rice cookie. Rice cookies are less dense and so more suited while still providing a very similar nutritional value to other common foods like oats, barley, and pasta.
To further offer a tiny quantity of nutrients to the edible wing, three types of edible adhesives were tested: gelatin, maize starch, and chocolate. Gelatin maintained a strong attachment until the material failure of the rice cookie itself. Gelatin was employed as an edible glue throughout the investigation since the team concluded that it was more durable than corn, starch, and chocolate.
Design and specifications
Wing loading is a crucial design factor for aeronautical structures since it affects the lift coefficient, stall speed, and, in the case of an edible drone, the amount of food it can carry. The planar construction was adhered with gelatin in a hexagonal pattern to reduce the extra mass added by the edible adhesive, as seen below.
One edible wing with a complete wingspan weighed 100 grams when the protective film was added. To prevent moisture damage, the entire wing surface was covered with plastic film and tape.
The electronics were placed in front of the fuselage for balance during flight. The fuselage was composed of a 0.5 m long hollow carbon rod. Two tiny servo motors were employed as actuators for the tail wing’s elevator and rudder, while a 300 kV brushless motor provided thrust.
A typical 2.4 GHz radio control transmitter and receiver set was used to remotely operate the motors. An 18.2 g Li-Po battery (7.4 V, 260 mAh) provided at least 10 minutes of flight time for the drone with edible wings. Without a payload, the total mass was 200 grams.
Despite being a prototype, the half-edible drone can fly, reaching speeds of roughly 10 meters per second after being equipped with a motor, several servos, and a small battery to control the tail surfaces.
Future research will focus on creating a novel method of storing payloads, such as water, on an edible drone without greatly expanding the surface area exposed to air. Since they are easy to make, it would be possible to use more than one edible drone to transport more food.
SOURCE: evtolinsights.com | spectrum.ieee.org