Multistimulus‐Responsive Miniature Soft Actuator with Programmable Shape‐Morphing Design for Biomimetic and Biomedical Applications

Abstract Miniature soft actuators have garnered attention across healthcare, military, and industrial fields; however, soft actuators mostly have functions and applications in nature‐inspired biomimetic locomotion, without any specific approaches reported for biomedical applications. In biomedical applications, soft actuators must be biodegradable, biocompatible, and visible in vivo. This study presents a multifunctional soft actuator comprising chitosan and magnetic nanoparticles (MNPs) fabricated via facile casting and laser micromachining. The actuator demonstrates programmable shape morphing and responds swiftly to six stimuli: humidity, chemical solvents, near‐infrared (NIR) light, radio‐frequency (RF) heating, temperature, and magnetic fields. This actuator shows feasibility for biomimetic applications, such as flower, leaf, larva, and finger. Furthermore, the actuator demonstrates magnetic locomotion, real‐time X‐ray visibility, biocompatibility, and biodegradability both in vitro and in vivo. The multistimulus‐responsive shape‐morphing performance of the soft actuator has potential as a wireless miniature robot in various fields, including biomimetic and biomedical applications.