image: Elucidating the adaptive odor-tracking mechanisms of an insect: A combined approach of biological analysis and engineering reconstruction.
Credit: © NII
A collaborative research group has developed a bio-inspired robotic system based on insect behavior which can locate odor sources both indoors and outdoors with consistent accuracy, even if one of its two sensors fails. The team includes Assistant Professor SHIGAKI Shunsuke of the National Institute of Informatics (NII; Director General: KUROHASHI Sadao; Chiyoda-ku, Tokyo), Professor KURABAYASHI Daisuke of the School of Engineering at Science Tokyo (President and Chief Executive Officer: OHTAKE Naoto; Meguro-ku, Tokyo), and Associate Professor OWAKI Dai of the Graduate School of Engineering at Tohoku University (Dean: Ito Akinori ; Sendai, Miyagi).
This breakthrough applies the biological principles of the silkworm moth (Bombyx mori), which can maintain effective navigation using only one antenna if the other is lost. By integrating these biological behavioral strategies into robotic design, the researchers have proposed a new framework for developing resilient autonomous systems.
The findings were published in the peer-reviewed journal npj Robotics (a Nature Partner Journal) on February 9, 2026.
Research Background
The ability to locate a destination by using odors (chemical substances) as cues constitutes a fundamental behavior shared among numerous living organisms. Despite possessing extremely small brains and relatively simple nervous systems, insects can rapidly detect odor molecules dispersed by the wind and orient themselves toward food sources or potential mating partners. Such odor-guided navigation has long been investigated from diverse biological perspectives, including neuroscience, genetics, and ethology. In recent years, increasing attention has been directed toward applying the sophisticated behavioral principles exhibited by these organisms to robotic systems. For example, robot platforms capable of detecting and tracking odor sources are anticipated to play pivotal roles in real-world applications such as disaster response, hazardous material and explosive detection, and environmental monitoring.
However, most conventional odor-guided robotic systems have been designed under the assumption that odor sensors on both the left and right sides function symmetrically and without impairment. In practical operational environments, sensor malfunction or physical damage may result in the loss of sensory input on one side, which represents a critical challenge leading to substantial performance degradation or even complete failure in odor source localization. To date, robotic systems that maintain robust performance under such asymmetric sensory deficiencies have not been fully established. To address this limitation, the present study proposes a novel framework that achieves robust odor source localization by drawing inspiration from adaptive behavioral strategies observed in biological organisms.
Summary of the Paper
In our paper, we employed adult male silkmoths (Bombyx mori) as a model organism and analyzed their odor source localization behavior guided by sex pheromones. Under intact conditions, silkmoths utilize a bilateral pair of antennae located on the head to acquire spatially distributed olfactory information, thereby enabling accurate localization of the odor source. Remarkably, behavioral experiments demonstrated that even after the loss of one antenna, the insects were still capable of reaching the odor source with high precision by appropriately selecting and modulating their behavior based solely on the olfactory input obtained from the remaining antenna. This finding revealed that silkmoths dynamically integrate information regarding the position of odor detection in a single antenna and their current heading angle, and flexibly adapt their behavioral decision-making processes in accordance with the prevailing conditions.
To validate the generality and effectiveness of the identified behavioral decision-making mechanism, we implemented the biologically inspired sensorimotor strategy in a robotic platform equipped with an olfactory sensor system analogous to that of the silkmoth. Using this robotic system, we conducted odor source localization experiments in both controlled indoor environments and complex outdoor settings. The results demonstrated that the robot maintained localization performance comparable to that observed prior to sensor impairment, even under conditions in which one of the bilateral sensors was disabled, not only indoors but also in outdoor environments characterized by substantial disturbances. The insect-inspired adaptive strategy successfully preserved a high success rate and efficient search performance. These results indicate the realization of robust odor-guided navigation under sensory impairment, a capability that has been difficult to achieve using conventional odor localization algorithms implemented in existing robotic systems.
This study represents a significant advancement in bio-inspired robotics, in which principles derived from biological behavior are translated into engineering systems. Furthermore, it provides critical design guidelines for robotic platforms endowed with long-term autonomous exploration capabilities, particularly in application scenarios such as disaster response and other challenging real-world environments.
Paper title and author
Paper Title：Insect-inspired adaptive behavioral compensation strategy against olfactory sensory deficiency for robotic odor source localization
Authors： Shunsuke Shigaki, Keisuke Yokota, Ryoko Sekiwa, Daisuke Kurabayashi, Dai Owaki
Journal： npj Robotics
DOI： https://doi.org/10.1038/s44182-026-00080-5
Published Date： 09 February 2026（EST）
###
About the National Institute of Informatics (NII)
NII is Japan's only academic research institute dedicated to the new discipline of informatics. Its mission is to "create future value" in informatics. NII conducts both long-term basic research and practical research aimed at solving social problems in a wide range of informatics research fields, from fundamental theories to the latest topics, such as artificial intelligence, big data, the Internet of Things, and information security.
As an inter-university research institute, NII builds and operates academic information infrastructure essential for the research and educational activities of the entire academic community (including the Science Information Network) as well as developing services such as those that enable the provision of academic content and service platforms.
https://www.nii.ac.jp/en/
About the Research Organization of Information and Systems (ROIS)
ROIS is a parent organization of four national institutes (National Institute of Polar Research, National Institute of Informatics, the Institute of Statistical Mathematics and National Institute of Genetics) and the Joint Support-Center for Data Science Research. It is ROIS's mission to promote integrated, cutting-edge research that goes beyond the barriers of these institutions, in addition to facilitating their research activities, as members of inter-university research institutes.
Journal
npj Robotics