Dual-Arm Platform for Control of Magnetically Actuated Soft Robots

The present work discusses a novel approach for remote magnetic actuation. In the following, we present a full characterization of the dual External Permanent Magnet (dEPM) actuation system. Herein, we discuss how this system can be applied to fully control the magnetic field in a predefined workspace. We discuss how it can generate a homogeneous magnetic field, in every direction and control every independent gradient in the same workspace. We prove how up to 8 Degrees of Freedom (DOF), 3 independent field components and 5 gradients directions, can be controlled fully independently. The rise in popularity of magnetic actuation comes from the fact that it allows for the control of wireless magnetic micro-robots and magnetic Soft Continuum Robots (SCRs), which bring about a reduction in size when compared to their non-magnetic counterparts. SCRs have a theoretical infinite number of DOFs and thus, can adapt to various nonlinear environments, minimising contact and pressure on surrounding tissue. While successful multi-DOFs magnetic actuation has been demonstrated at small scale, by using systems of coils, large-scale manipulation is yet to be fully proven. In fact, it might require several independently- controlled coils to be effective along any possible direction of motion. Despite their ability to generate both homogeneous fields and gradients, systems of coils are less scalable, compared to permanent magnet- based magnetic field control systems. In fact, due to lower field density, energy-consumption and need for high-performance cooling systems, they are generally characterized by limited workspace. By further developing the idea of remotely actuating 1 Internal Permanent Magnet (IPM) (internal since, generally, inside the human body) with 1 External Permanent Magnet (EPM), we discuss how 2 robotically actuated EPMs are able to magnetically manipulate 2 IPMs, independently. This is achieved by independently controlling the torque (magnetic field) and the force (field gradients) applied to each IPM.