• Researchers from the University of Washington and the University of Maryland associated with the Air Force Center of Excellence on Nature-Inspired Flight Technologies and Ideas (NIFTI) have developed “smellicopter”, an autonomous drone that uses a live antenna from a moth to navigate toward smells.
• A smellicopter can sense and avoid obstacles as it travels through the air. The results were recently published in the journal IOP Bioinspiration & Biomimetics.
What is the significance of smellicopter?
• One huge advantage of drones is that these little robots can go places where people can’t, including areas that might be too dangerous, such as unstable structures after a natural disaster or a region with unexploded devices.
• Researchers are trying to develop devices that can navigate these situations by sniffing out chemicals in the air to locate disaster survivors, gas leaks, explosives and more. But most sensors created by people are not sensitive or fast enough to be able to find and process specific smells while flying through the patchy odour plumes these sources create.
• Biohybrid systems integrate living materials with synthetic devices, exploiting their respective advantages to solve challenging engineering problems. Many flying animals depend on their ability to detect and locate the source of aerial chemical plumes for finding mates and food sources. A robot with comparable capability could reduce human hazard and drastically improve performance on tasks.
• Smellicopter is a flying biohybrid system which successfully performed odour localisation in a confined space, and it was able to do so while detecting and avoiding obstacles in its flight path.
How was it developed?
• Smellicopter takes a different approach by incorporating a live antenna from a moth as a sensor. Moths use their antennae to sense chemicals in the environment and navigate toward sources of food or potential mates.
• The researchers used antennae from the Manduca sexta hawk moth for smellicopter. Researchers placed moths in the fridge to anesthetize them before removing an antenna. Once separated from the live moth, the antenna stays biologically and chemically active for up to four hours. That time span could be extended by storing antennae in the fridge.
• By adding tiny wires into either end of the antenna, the researchers were able to connect it to an electrical circuit and measure the average signal from all of its cells.
• The team then compared it to a typical human-made sensor by placing both at one end of a wind tunnel and wafting smells that both sensors would respond to: a floral scent and ethanol. The moth antenna reacted more quickly and took less time to recover between puffs than the artificial sensor.
• To create smellicopter, the team added the antenna sensor to a small, open-source, customizable quadcopter. The researchers also added two plastic fins on the back of the drone to create drag to help it be constantly oriented upwind.
• It uses a camera to survey its surroundings, similar to how insects use their eyes. This makes the smellicopter well-suited for exploring indoor or underground spaces.
• Smellicopter is naturally tuned to fly toward smells that moths find interesting, such as floral scents. But researchers hope that future work could have the moth antenna sense other smells, such as the exhaling of carbon dioxide from someone trapped under rubble or the chemical signature of an unexploded device.