Design and Modeling of a Multi-DoF Magnetic Continuum Robot with Diverse Deformation Modes

Magnetically-actuated continuum robots (MCRs) have the potential to be miniaturized to submillimeter sizes. However, their limited deformation modes hinder their ability to navigate through narrow and tortuous lumens. In this letter, we introduce a novel 2-degrees of freedom (DoF) MCR with diverse deformation modes. To validate the concept, a 20 mm-long MCR is fabricated. We also present an optimization algorithm to expand the MCR's workspace, relying on a deformation estimation algorithm that has been experimentally proven to have an error of less than 1.15 mm on the fabricated prototype. The optimized MCR exhibits a 40% larger workspace compared to conventional MCRs. Additionally, we integrate the 2-DoF MCR with mechanical devices and propose a Jacobian-based control scheme for them. Experimental results confirm its capability for tip trajectory tracking tasks with an RMS error of 0.71 mm and demonstrate its ability for obstacle avoidance. These innovations hold significant implications for the development of MCRs, paving the way toward more efficient interventional procedures.