Imaging Technologies for Biomedical Micro‐ and Nanoswimmers

The last decade has seen the rapid development of untethered mobile micro‐ and nanorobots able to navigate liquids by means of external power sources or by harvesting chemicals from their surrounding media. These tiny devices hold great promise for applications in the biomedical field including targeted drug delivery, localized diagnostics, microsurgery, and cell stimulation. However, to translate small‐scale robots from the laboratory to the clinic, many challenges remain. A major obstacle is the lack of imaging technologies that will allow for precise tracking of the devices in vivo. Here, the current progress, challenges, and future possibilities in the monitoring and tracking of biomedical micro‐ and nanomachines using established as well as less conventional imaging technologies are reviewed.