Over the past few years, the team has built up expertise in bo | FönX

Over the past few years, the team has built up expertise in both hydrogels — biocompatible materials made mostly of water — and 3-D-printed magnetically-actuated materials that can be designed to crawl, jump, and even catch a ball, simply by following the direction of a magnet.
In this new paper, the researchers combined their work in hydrogels and in magnetic actuation, to produce a magnetically steerable, hydrogel-coated robotic thread, or guidewire, which they were able to make thin enough to magnetically guide through a life-size silicone replica of the brain’s blood vessels. https://news.mit.edu/2019/robot-brain-blood-vessels-0828 Nanobots replacing neurons

They have enough power to go upstream and to move spherical particles.

Tiny microrobots could travel the bloodstream to one day deliver cancer drugs to hard-to-reach tumors deep inside the body.

Scientists use magnetic fields to precisely control nanomachines swimming through blood-like fluid - Electronic Products https://www.electronicproducts.com/scientists-use-magnetic-fields-to-precisely-control-nanomachines-swimming-through-blood-like-fluid/ [IBEC] Smart nano-bio-devices group - Graphene motors -nl6b00768 si 003

[IBEC] Smart nano-bio-devices group - micro robots transporting particles