This Biohybrid Drone Is On the Scent

Whatever we can do, nature already seems to have done better. Flight efficiency, environmental sensing, energy storage, self-healing materials — you name it, nature has us beat. It is not even close. Rather than being discouraged by the fact that we are not nearly as brilliant of engineers as we believe ourselves to be, we should draw inspiration from the natural world. By incorporating some of the strategies and designs found in nature, we can create more efficient, sustainable, and innovative solutions to move our technological capabilities forward.

Consider drones, for instance. Innovation in this area is sorely needed. Much attention goes to improving drone flight efficiency, as their spinning rotors very rapidly drain batteries. But another crucial component of a drone is its navigation system. Drone navigation typically relies on cameras and machine learning algorithms, but these systems fail in low light, bad weather, and under any other conditions that limit visibility.

As you might expect, nature has a great many solutions to these problems. One of the more exotic solutions involves navigation via odor-source localization, which creatures such as the silkworm moth rely on. It may not be as precise as a vision-based method, but it has been known to guide insects to a target several miles away. And when vision-based methods fail, it just might be what we need to guide our drones as well, says a group led by researchers at Chiba University in Japan.

The team has developed a biohybrid drone that uses conventional technologies for flight, but that is also equipped with the odor-sensing antennae from silkworm moths. Unlike conventional drones that rely solely on cameras, LiDAR, or thermal imaging, this biohybrid drone can detect and track airborne chemical signatures, allowing it to operate effectively in environments where visibility is poor, such as during search-and-rescue missions in collapsed buildings or disaster-stricken areas.

At the heart of this system is an electroantennography (EAG) sensor, which detects odor molecules by measuring the electrical signals emitted by the moth antennae when they encounter specific chemicals in the air. The researchers previously developed an early version of this biohybrid drone, but its odor-detection range was limited to about two meters. To overcome this, they introduced a new "stepped rotation algorithm" that mimics the way insects pause intermittently while tracking scents. This adaptation significantly improved detection accuracy, allowing the drone to effectively sense odor sources from up to five meters away.

In addition to refining the software, the team made some significant hardware improvements. They redesigned the electrodes and EAG sensor to better accommodate the silkworm moth antennae, improving their responsiveness to odor stimuli. A funnel-shaped enclosure was also added to reduce airflow resistance, while a conductive coating was applied to minimize interference from electrostatic noise. These modifications resulted in a drone that is not only more sensitive to odors, but also more reliable in real-world applications.

While the biohybrid drone still has limitations, such as the relatively short lifespan of the biological components, the researchers are actively exploring solutions, including techniques to preserve or artificially replicate insect antennae. If successful, these advances could pave the way for a new era of bioinspired robotics that leverage the best of both natural and engineered systems.