Thermometric Based‐Microswimmers with Chemical and Optical Engines

The development of microswimmers with integrated sensing elements opens new avenues for advanced functionalities in microscale environments. Among these, temperature sensing is critical for applications ranging from biomedical diagnostics to catalytic process monitoring. However, most luminescent thermometry approaches rely on passive particles, which lack mobility and require accumulation strategies for localized sensing. Herein, a conceptual study on dual‐mode microswimmers that combine autonomous motion with luminescent temperature sensing in a single platform is presented. The microswimmers consist of Yb 3+ and Er 3+ ‐codoped NaYF 4 microparticles coated with ZnO and Pt, enabling light‐ and fuel‐driven propulsion modes. The use of Er 3+ ‐based emission provides reliable thermometric response in the physiologically relevant range of 297–333 K. Although real‐time temperature readout during motion requires further development, this work establishes a foundational step toward mobile thermometric probes with potential applications in localized thermal mapping and responsive sensing in complex environments.