Pattern architected soft magnetic actuation†

Abstract

Bioinspired shape-morphing soft magnetic actuators have potential applications in medicine, robotics, and engineering due to their soft body, untethered control, and infinite degrees of freedom. The shape programming of the soft magnetic actuators (consisting of soft ferromagnetic CI particles in a soft matrix) is an involved task, as it requires a moulding process severely limiting the capability to program complex shapes. The current study explores a shape programming technique that architects the particle pattern configuration in the actuator, mimicking the pattern found in the mould-programmed actuator, thereby eliminating the need for a mould and providing a greater capability of programming complex shapes. At first, actuators with some basic shapes are prepared using the mould programming technique and examined under a microscope to understand the configuration of particle alignment patterns in different shapes. Then, the pattern is architected using magnetic units in the soft matrix to eliminate the need for mould for shape programming. In this study, the programmed soft actuators are characterized for shape morphing and locomotion capability under an external actuating magnetic field. The crawler was found to move at a velocity of 3 mm s⁻¹ under a periodic magnetic field of 1 Hz. The designed actuators are found to quickly respond to the magnetic field thereby generating the desired shapes.