Foundational Mechanisms of Visual-Perception Control in Cyborg Insects Using UV Stimulation

Cyborg insects are often controlled using invasive electrical stimulation, which can affect sensory function and reduce response stability during repeated use. This study presents a non-invasive control method that uses the natural ultraviolet (UV) avoidance response of the Madagascar hissing cockroach (Gromphadorhina portentosa) to guide locomotion. A lightweight UV helmet was designed to stimulate either the Left Compound Eye (LCE) or the Right Compound Eye (RCE) to induce directional turning. Neural activity, behavioral responses, turning angles, and navigation performance were evaluated using neural recordings, behavioral observations, motion-capture tracking, and a manual S-shaped path navigation task. Unilateral UV stimulation produced consistent contralateral turning with a median turning angle of approximately -27^∘ , whereas electrical stimulation produced larger turns of about -35^∘ . Neural recordings showed only a small increase in firing activity during UV stimulation, while firing variability remained similar to the baseline condition. In the S-shaped navigation task, cockroaches guided by UV stimulation required longer navigation times ( 62.4 ± 15.2~s ) than those controlled by electrical stimulation ( 48.7 ± 10.5~s ). However, repeated trials showed that UV-induced turning responses remained relatively stable, whereas electrical stimulation gradually reduced turning responses over time. These results demonstrate that UV-based stimulation provides a stable and non-invasive method for directional control in cyborg insect navigation while preserving natural sensory pathways.