Mechanically Assisted Magnetic Actuation in Ceramic-Based Microscrolls for Fast and Durable Soft Robotic Systems.

Abstract

Soft magnetic actuators capable of fast, remote, and untethered motion are increasingly sought for microscale robotic systems. Here, we introduce compact ceramic-based, magnetically responsive microscroll actuators inspired by the coiled geometry of the butterfly proboscis. The actuators are fabricated from hybrid films composed of aligned vanadium pentoxide (V₂O₅) nanofibers and Fe₃O₄ nanoparticles distributed within the nanofiber matrix, forming a flexible, laminated architecture with enhanced mechanical robustness. Using a razor blade-assisted scrolling method, the planar films are transformed into tightly wound microscrolls with tunable geometry and micrometer scale diameters. Under near-field magnetic stimulation (∼60 mT), the scrolls exhibit rapid, reversible, and multidirectional actuation with angular displacements of up to 180°. The actuation relies on a dual magneto-mechanical mechanism: distributed magnetic stresses generated by the embedded Fe₃O₄ phase initiate unrolling, while residual elastic strain stored during scrolling drives the re-rolling motion. This geometry-programmed actuation enables a lifting ratio of 32.5× relative to actuator mass, a work density of ∼8.1 kJm^- ³, and a footprint reduction of up to 96%. Notably, the ceramic-based microscrolls retain structural and functional integrity over 5000 magnetic actuation cycles, demonstrating a durable architecture-driven route toward untethered soft robotic microsystems.