Experimental Evaluation of Haptic Shared Control for Multiple Electromagnetic Untethered Microrobots

Abstract

The precise manipulation of microrobots presents challenges arising from their small size and susceptibility to external disturbances. To address these challenges, we present the experimental evaluation of a haptic shared control teleoperation framework for the locomotion of multiple microrobots, relying on a kinesthetic haptic interface and a custom electromagnetic system. Six combinations of haptic and shared control strategies are evaluated during a safe 3D navigation scenario in a cluttered environment. 18 participants are asked to steer two spherical magnetic microrobots among obstacles to reach a predefined goal, under different conditions. For each condition, participants are provided with different obstacle avoidance and navigation guidance cues. Results show that providing assistance in avoiding obstacles guarantees safer performance, regardless if the assistance is autonomous or delivered through a haptic repulsive force. Moreover, autonomous obstacle avoidance also reduces the completion time by 30% compared to haptic obstacle avoidance and no obstacle avoidance cases, although haptic feedback is preferred by the users. Finally, providing haptic guidance towards the target improves by the 65% the positioning accuracy of the microrobots with respect to not providing this guidance. We also present some illustrative scenarios to generalize the presented haptic shared control strategies to arbitrary formations of N microrobots, while showing the effectiveness of the method for a clinical use-case of endovascular navigation in simulated environment. Note to Practitioners—The recent increasing interest in microrobotics arises from its potential applications in fields like medicine, manufacturing, and environmental monitoring, enabling highly precise control of minimally invasive tools. By enabling users to teleoperate microscale tools with partial autonomous support, these systems facilitate safe access to confined spaces, enhance task efficiency, and enable navigation in otherwise inaccessible environments. Our presented solution serves as an experimental platform to evaluate the efficacy of different combinations of tactile feedback and partial autonomy during safe navigation tasks, with potential applications spanning microsurgery, drug delivery, microscale manufacturing, and environmental remediation. Further practical adaptation of the system will require defining specific application objectives and specifications, along with potential modifications to the actuation system to accommodate environmental constraints of targeted scenarios.