Self-deployed magnetic polygons: Design, construction, and application

This paper reports the development of self-deployed magnetic polygons at the centimeter scale. These permanent-magnet (NdFeB) devices can be folded into a constraining catheter for delivery, before spontaneously unfolding into a polygon upon extrusion. The devices use a combination of dipolar and quadrapolar magnetic components along their sides, which facilitate self-deployment. Four-, six-, and eight-sided devices are reported and the effects of varying the geometry, the number of sides, and the duty cycle of the quadrapolar sides are examined in simulation and through experimental testing. As well as self-deployment, two $N$-sided devices $(N\in\{4,6,8\}) $ are capable of face-to-face magnetic mating of opposing north and south poles with a minimum of difficulty. This capability is justified by modeling of the system's magnetic potential energy, and by experimental validation. Optimized design parameters are proposed. Magnetic mating of two $N$-sided devices facilitates applications where access to an adjoining orifice is desirable with a minimally sized access port (e.g., in the case of minimally invasive surgical technology). Current and future applications are considered.