‘Smellicopter’ makes use of a stay moth antenna to search for smells – GCN
‘Smellicopter’ uses a moth antenna to look for smells
An autonomous drone called a smellicopter uses a moth’s live antenna to navigate towards smells.
It can also detect and avoid obstacles when moving through the air.
A big advantage of drones is that these little robots can reach places that humans cannot live, including areas that are considered too dangerous, such as the B. unstable structures after a natural disaster or a region with unexploded equipment.
Researchers are keen to develop devices that can control these situations by detecting chemicals in the air to locate survivors from disasters, gas leaks, explosives, and more. Most sensors, however, are not sensitive or fast enough to find and process certain smells as they fly through the mottled plumes of odor these sources create.
“Nature really blows our man-made odor sensors out of the water,” says lead author Melanie Anderson, a doctoral student in mechanical engineering at the University of Washington. “By using a moth antenna with a smellicopter, we can get the best of both worlds: the sensitivity of a biological organism on a robot platform on which we can control its movement.”
The moth uses its antennae to sense chemicals in its environment and to navigate to food sources or potential partners.
“Cells in a moth antenna amplify chemical signals,” says co-author Thomas Daniel, professor of biology who supervises Anderson’s doctoral thesis. “The moths do this really efficiently – a scent molecule can trigger a lot of cellular responses, and that’s the trick. This process is very efficient, specific and fast. “
The team used antennas from the Manduca sexta hawkmoth for smellicopters. The researchers put moths in the refrigerator to numb them before removing an antenna. Once separated from the living moth, the antenna remains biologically and chemically active for up to four hours. That length of time could be extended, say the researchers, by storing antennas in the refrigerator.
By adding tiny wires to either end of the antenna, the researchers were able to connect it to a circuit and measure the average signal from all cells in the antenna. The team then compared it to a typical man-made sensor placed both at one end of a wind tunnel and with wafting smells that both sensors would respond to: a floral scent and ethanol, a type of alcohol. The antenna responded faster and took less time to recover between pulls.
Smell houses house odors
To develop smellicopters, the team added the antenna sensor to a commercially available open-source quadcopter drone platform that allows users to add special functions. The researchers added two plastic fins to the back of the drone to create drag so it could be constantly pointed against the wind.
“From a robotics perspective, this is a genius,” says co-author and consultant Sawyer Fuller, assistant professor of mechanical engineering. “The classic approach in robotics is to add more sensors and possibly create a fancy algorithm or use machine learning to estimate wind direction. It turns out that all you have to do is add one fin. “
Smellicopter doesn’t need any help from researchers to look for smells. The team created a “cast and surge” protocol for the drone, mimicking the way moths search for scents. Smellicopter begins its search by moving left for a certain distance. If nothing exceeds a certain odor threshold, the Smellicopter will move the same distance to the right. As soon as it detects an odor, it changes its flight pattern to approach it.
With the help of four infrared sensors, the smellicopter can also avoid obstacles, with which it can measure what is around it ten times per second. If something is within 8 inches of the drone, it changes direction by moving on to the next stage of its cast-and-surge protocol.
“So if Smellicopter has thrown to the left and there is now an obstacle on the left, it changes to the right,” says Anderson. “And if the Smellicopter smells a smell but there is an obstacle in front of it, it will keep throwing to the left or right until it can shoot forward if there is no obstacle in its path.”
N0 GPS required
Another advantage of the smellicopter is that it doesn’t require GPS, the team says. Instead, it uses a camera to survey its surroundings, much like insects use their eyes. This makes smellicopters well suited for exploring indoor or underground spaces such as mines or pipes.
During the tests, the smellicopter was of course set up to detect odors that moths find interesting, such as: B. floral fragrances. However, the researchers hope that in future work the moth antenna could sense other smells, such as the exhalation of carbon dioxide from someone trapped under debris or the chemical signature of a device that has not exploded.
“Finding spring sources is a perfect job for small robots like the smellicopter and the Robofly,” says Fuller. “Larger robots can carry around a number of different sensors and use them to create a world map. We can’t really do that on a small scale.
“But to find the source of a cloud, a robot just needs to avoid obstacles and stay in the cloud while moving against the wind. No sophisticated sensor suite is required for this – it just has to smell good. And that’s exactly what the smellicopter is really good at. “
Other co-authors are the University of Maryland and the University of Washington. The work was funded by the National Defense and Engineering Graduate Fellowship, the Washington Research Foundation, the Joan and Richard Komen Endowed Chair, and the Air Force Office of Scientific Research at the Air Force Center of Excellence for Nature-Inspired Flight Technologies and Ideas.
This article was shared by Futurity.
Sarah McQuate is a public information engineer at the University of Washington.