CAMP: Closed-Loop Acoustic-Magnetic Propulsion of Microrobots for Precision Cell Manipulation.

Developing microrobotic systems for accurate and fast manipulation of microobjects or living cells has the potential to significantly advance biomedical and microfabrication applications. Despite recent progress in this field, comprehensive multistimuli responsive, fast, and precisely controllable microrobots remain limited. In this study, automated position and speed control of acoustically powered, bubble-based, magnetically steerable microrobots is demonstrated, along with micromanipulation of mammalian cells using these microswimmers. Enhanced control of the microswimmers is achieved by designing and implementing a closed-loop control system that guides the microrobots along a predetermined path while modulating their speed by adjusting the acoustic frequency near the resonant value. The microrobots are guided to cells, enabling cell manipulation by pulling them with the microrobots. Overall, the results highlight the capability and controllability of these magnetically and acoustically responsive microrobots for future cell-based applications, including manipulation, delivery, and microsurgery.