These tiny cages, each 100 microns long and 40 microns wide, may not look like much, but they are the new semi-trucks of targeted medicine delivery. Developed by a team of Chinese researchers, in conjunction with Swiss and South Korean institutes, the nickel-coated microbots are steered wirelessly by electromagnetic fields. Thanks to that external control, these microbots can carry precious cargo to exactly where the body needs it, in especially to sensitive places like brains or eyes.

Tiny robots swimming through blood for medical purposes are a relatively new phenomena. In 2011, researchers published a paper on miniscule motors that could propel such machines.