Magnetic Navigation of a Rotating Colloidal Swarm Using Ultrasound Images
This work addresses the challenge of imaging microrobots in vivo for biomedical applications, though it appears incremental as it builds on existing magnetic navigation and ultrasound imaging techniques.
The researchers tackled the problem of imaging microrobots in biomedical applications by using ultrasound to visualize and navigate a paramagnetic nanoparticle swarm, achieving enhanced imaging contrast compared to individual nanoparticles and stable navigation near surfaces.
Microrobots are considered as promising tools for biomedical applications. However, the imaging of them becomes challenges in order to be further applied on in vivo environments. Here we report the magnetic navigation of a paramagnetic nanoparticle based swarm using ultrasound images. The swarm can be generated using simple rotating magnetic fields, resulting in a region containing particles with a high area density. Ultrasound images of the swarm shows a periodic changing of imaging contrast. The reason for such dynamic contrast has been analyzed and experimental results are presented. Moreover, this swarm exhibits enhanced ultrasound imaging in comparison to that formed by individual nanoparticles with a low area density, and the relationship between imaging contrast and area density is testified. Furthermore, the microrobotic swarm can be navigated near a solid surface at different velocities, and the imaging contrast show negligible changes. This method allows us to localize and navigate a microrobotic swarm with enhanced ultrasound imaging indicating a promising approach for imaging of microrobots.