Magnetically Maneuvered Quantum Sensors

ABSTRACT We report a hybrid quantum sensing platform that integrates nitrogen‐vacancy (NV) center–containing nanodiamonds with magnetically actuated helical microbots, enabling untethered quantum sensing in complex fluidic environments. The Mobile Quantum Sensor (MQS) platform is constructed by attaching single or multiple nanodiamonds onto wafer‐fabricated microhelices, yielding a scalable materials architecture. This hybrid approach decouples magnetic actuation from optical interrogation, mitigating the heating and phototoxicity limitations inherent to optical and thermophoretic manipulation methods while preserving quantum functionality. We demonstrate robust, in‐situ optically detected magnetic resonance (ODMR) and, for the first time, coherent spin control via Rabi oscillations in a mobile, maneuverable sensor. External magnetic fields allow deterministic three‐dimensional positioning and orientation, while dynamic reorientation suppresses rotational noise from Brownian motion. By uniting the spin coherence of diamond nanomaterials with the controlled mobility of engineered microstructures, this approach establishes a versatile and scalable route for real‐time mapping of temperature and vector magnetic fields in fluidic microenvironments, advancing multifunctional quantum‐enabled materials systems for biomedical, environmental, and materials applications.