The robot inside a model artery Kim et al., Sci. Robot. 4, eaax7329 (2019)

A tiny robotic worm can wiggle its way through a model brain. It could eventually be used to make brain surgeries less invasive.

Yoonho Kim and his colleague Xuanhe Zhao at Massachusetts Institute of Technology created the robot out of a polymer with small magnetic particles embedded throughout, meaning it can be directed using a magnet. It is coated in a self-lubricating material and is less 0.6 millimetres in diameter.

The pair tested the robot on a silicone model of a human brain, which contained a substance that mimics blood. When controlled with a magnet held outside the brain, the robot could worm its way through hard-to-reach blood vessels.


“The reason why robotics couldn’t go into this domain before is the existing robots that can navigate through a blood vessel were too large in diameter,” says Kim. Instead robots are used in the heart, where arteries are wider.

The magnetic microparticles also show up on continuous x-ray systems, so could be used to help surgeons navigate the tricky web of arteries and veins in the brain.

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“I think it’s really interesting – and the clinical implications are there, if at a very early stage,” says Eloise Matheson at Imperial College London. “The system, how they tested it and what it shows, is really promising.”

The next step, says Kim, is to test the device on animals, which the duo is in talks with neurosurgeons at Harvard Medical School about doing.

Journal reference: Science Robotics, DOI: 10.1126/scirobotics.aax7329