Laser-induced in situ reprogramming of magnetic shape memory composites for adaptive devices

Abstract Programmable/reprogrammable magneto-responsive composites (MRCs) are highly desirable for applications in soft robotics, morphable actuators, and biomedical devices due to their capabilities of undergoing reversible, complex, untethered, and rapid deformations. However, current MRC-based devices primarily rely on soft matrices, which revert to their original shapes and cease functioning when external magnetic fields are removed. Moreover, their magnetization programming, deformations, and functioning need to alternate between encoding and actuation platforms, limiting the adaptability and efficiency. Here, we present a reprogrammable magnetic shape-memory composite (RM-SMC) integrating a shape-memory polymer (SMP) skeleton with phase-transition magnetic microcapsules. High-intensity laser melts microcapsules for magnetic realignment under programmed fields, while low-intensity laser softens SMP for structural reconfiguration without compromising integrity. This dual-laser strategy facilitates in situ magnetization programming, shape morphing, and function execution within a single material system. Our innovative approach enables unique applications, including omnidirectional multi-degree-of-freedom actuators that can activate light switches, solar trackers that optimize energy capture, and adaptive impellers that modulate fluid pumping. By eliminating platform alternation and enabling shape/function retention post-actuation, the RM-SMC platform overcomes critical limitations in conventional MRCs, establishing a paradigm for multifunctional devices requiring persistent configuration control and field-independent operation.