Metal‐Based Transient Micromotors: From Principle to Environmental and Biomedical Applications

: Inspired by transient devices, transient self-destroying micromotors that are propelled by metal-water/acid reactions and autonomously disappear after completing their tasks have emerged as promising tools for diverse applications. Such transient machines require careful selection of the metal matrix and well-designed architectures for effective propulsion and customized functionality. In particular, recent advances in transient micromotors based on the active metals Zn, Fe, and Mg are introduced here. First, the fundamental design principles of transient micromotors are discussed. Then, their recent progress in environmental and biomedical applications is highlighted.