Scientists from Osaka University, Hiroshima University, and Nanyang Technological University, Singapore (NTU Singapore) have pioneered a swarm navigation system for cyborg insects, paving the way for their use in disaster relief, search-and-rescue missions, and infrastructure inspection.
Their innovative system uses a leader-follower dynamic, where one cyborg insect acts as a group leader guiding others. When scaled up and developed, the swarm technology can complement disaster relief, search-and-rescue efforts, and infrastructure inspection by allowing cyborg insects to efficiently navigate hazardous and inaccessible terrains to search for survivors in the aftermath of a disaster or to detect concrete defects in infrastructures.
Researchers led by Naoki Wakamiya from Osaka University and Masaki Ogura from Hiroshima University developed the swarm control algorithm and the computer programs, while the scientists led by Professor Hirotaka Sato from NTU Singapore's School of Mechanical and Aerospace Engineering prepared the cyborg insect swarm, implemented the algorithm on the insects' electronic backpacks, and conducted the physical experiments at the NTU School of Mechanical and Aerospace Engineering.
Published in Nature Communications this week, the findings represent a major milestone in the field of swarm robotics as earlier research only demonstrated control of a single cyborg or had implemented control algorithms that required detailed and complex instructions for each insect, which are not feasible for achieving coordinated movement of a big group.
With the new method, the leader insect is notified of the intended designation, and its control backpack will coordinate with the others in the group to guide the swarm. This "tour leader" approach allows the swarm to adapt dynamically, as the insects can assist each other to overcome obstacles, adjusting their movements if one member becomes trapped.
The insects used are Madagascar hissing cockroaches equipped with a lightweight circuit board, sensors, and a rechargeable battery on their backs, forming an autonomous navigation system that will help them navigate their surroundings and nudge them towards a target.
These cyborgs consume significantly less energy than traditional robots, which rely on power-intensive motors for movement. The insects' natural instincts, when combined with the swarm control algorithm, enable them to navigate complex terrains and respond rapidly to environmental changes.
In experiments, the new algorithm reduced control interventions by about 50 per cent compared to earlier approaches and resolved prior issues such as insects becoming stuck or trapped in obstacles. This innovation will be useful for urban search-and-rescue missions and infrastructure inspection, where narrow spaces and unpredictable conditions render conventional robots less effective.
As a co-corresponding author of the paper, Wakamiya says "Unlike robots, insects do not behave as we intend them to. However, instead of forcibly trying to control them precisely, we found that taking a more relaxed and rough approach not only worked better but also led to the natural emergence of complex behaviors, such as cooperative actions, which are challenging to design as algorithms. This was a remarkable discovery. While their actions may appear haphazard at first glance, there seems to be a great deal we can still learn from the sophisticated and intricate behaviors of living organisms."
Co-corresponding author of the paper, Ogura says "Our swarm control algorithm represents a significant breakthrough in coordinating groups of cyborg insects for complex search-and-rescue missions. This innovation has the potential to greatly enhance disaster response efficiency while also opening new avenues for research in swarm control. It underscores the importance of developing control methods that perform effectively in real-world scenarios, going beyond theoretical models and simulations."
Co-corresponding author, Sato says the technology is envisioned to be helpful in search and rescue missions, infrastructure inspection, and environmental monitoring, when hundreds of cyborg insects are deployed. "To conduct search and inspection operations, large areas must be surveyed efficiently, often across challenging and obstacle-laden terrain. The concept involves deploying multiple swarms of cyborg insects to navigate and inspect these obstructed regions.
Their latest breakthrough underscores the practical potential of biohybrid systems in addressing real-world challenges and the importance of global interdisciplinary research collaborations.
The joint team envisions several applications for this technology, including disaster relief operations, where cyborg swarms can locate survivors in collapsed buildings, map obstacles, and identify safe paths for rescue teams. Other potential uses include environmental monitoring in dense forests and hazardous zones and infrastructure inspection.
Looking ahead, the joint team aims to develop algorithms that enable coordinated swarm actions beyond simple movements, such as collaboratively transporting large objects.
They also plan to conduct experiments in outdoor environments, including rubble piles commonly found in disaster zones, to validate the algorithm's effectiveness in more complex and real-world scenarios.
Fig. 1
An illustration depicting multiple cyborg insects moving in a swarm, following a single leader cyborg.
Credit: 2024 Wakamiya et al., Swarm navigation of cyborg-insects in unknown obstructed soft terrain., Nature Communications
Fig. 2
An image of the actual experiment, with the cyborg insect in the foreground acting as the leader.
Credit: 2024 Wakamiya et al., Swarm navigation of cyborg-insects in unknown obstructed soft terrain., Nature Communications
The article, "Swarm navigation of cyborg-insects in unknown obstructed soft terrain," was published in Nature Communications at DOI: https://doi.org/10.1038/s41467-024-55197-8.
