Abstract
Microrobots have attracted great attentions due to their wide applications in microobjects manipulation and targeted drug delivery. To realize more complex micro/nano cargos manipulation (e.g., encapsulation and release) in biological applications, endowing microrobots with shapes adaptability with the environment is highly desirable. Here, designable shape-morphing microrobots (SMMRs) have been developed by programmatically encoding different expansion rate in a pH-responsive hydrogel. Combined with magnetic propelling, the shape-morphing microcrab (SMMC) is capable of performing targeted microparticle delivery, including gripping, transporting, and releasing through claws morphing. As a proof-of-concept demonstration, the shape-morphing microfish (SMMF) is designed to encapsulate drug (doxorubicin (DOX)) by closing mouth in phosphate buffer saline (PBS, pH~7.4) and release them by opening mouth in slightly acid solution (pH<7), which realize localized Hela cells treatment in an artificial vascular network. These SMMRs with powerful shape morphing capabilities and remote motion controllability provide new platforms for complex microcargos operation and on-demand drug release.