Cyborg Insects as Biohybrid Robots: Experimental Modeling and Sliding Mode Control

The concept of Cyborg Insects has attracted considerable attention in recent years due to their great potential in various fields such as agriculture, surveillance and rescue operations. Although not an entirely new concept, thanks to the improvements in technology and the reduction in the size of electronic components, new frontiers have opened up in the study of these systems. More recent research involves integrating electronics and sensors onto the bodies of insects (in this research, Madagascar Hissing Cockroaches) to allow remote control of their movements, trajectories and behaviors. A combination of microelectronics and neuro-engineering techniques is used to achieve this integration, including wireless communication systems, miniaturized sensors and neural interfaces. Due to their small size and ease of programming, these cybernetic systems could represent a better alternative to regular microrobots, as the latter may take longer to program and would likely have difficulty moving in confined spaces and rough terrain. The research activity for my thesis comprehensively explores different types of electrical stimulation of the cyborg insect, studying the concept of habituation to stimuli and methods to avoid it. This is done by analyzing the effect of changing different parameters in the electrical signals provided as input to the hybrid robot. The second part of the activity is dedicated to finding a kinematic mathematical model capable of describing the behavior of a real cockroach in response to electrical stimulations taking into account its non-linearities. The model obtained is then implemented in MATLAB/Simulink. A Sliding Mode Control algorithm is designed and applied for tracking the trajectory of the cyborg insect, improving motion planning and showing very promising results for the applicability of the Variable Structure Control strategies in living systems such as cockroaches. The research activity of the thesis led to the publication of two conference papers and one article in an IEEE international journal. In particular, the results regarding experiments and modeling were presented at the 41st Annual Conference of the Robotics Society of Japan (RSJ 2023), September 11-14, 2023, Sendai International Center, Miyagi Prefecture and the paper published in the conference proceedings. The results about Variable Structure Control for Cyborg Cockroaches were published in a paper in the IEEE Control Systems Letters, 2023, and will be presented at the 2024 American Control Conference (ACC 2024), July 8-12, 2024, Toronto, Canada, the paper will also be published in the conference proceedings (joint submission ACC 2024 and IEEE L-CSS).