Researchers demonstrated an early proof-of-concept system in which tiny robots inside your body, controlled by an MRI machine, could self-assemble into a Gauss gun and fire projectiles to clear blockages or deliver drugs. Video below.
Aaron Becker, Ouajdi Felfoul, and Pierre E. Dupont from University of Houston and Boston Children's Hospital presented their work at the recent IEEE International Conference on Robotics and Automation (ICRA). From IEEE Spectrum:
The robots haven't been "milli-ized" yet, so these first tests aren't at bloodstream scale, but as a proof-of-concept system, it seems very effective…
The magnets used here are steel, which (inside of an MRI) become more magnetic than neodymium. The projectile is a needle that could be loaded with drugs, or just used to punch through (say) a blood clot. Once these robots are made small enough, they could navigate through the fluids in our body (including the bloodstream and the fluid in our spine) to a target area to perform tasks like "puncturing a membrane to release trapped fluid, opening a blocked passageway or delivering a drug to a tissue location several centimeters from a fluid-filled space," according to the researchers. It's not at all difficult to imagine how an injection of robots could travel directly to the site of a problem, treat that problem directly, and then travel right back out again, resulting in a much more effective treatment with fewer side effects for a whole range of conditions.
"Self-Assembling Robotic Gun Will Shoot Through Tissue Inside Your Body"
"PDF: Toward Tissue Penetration by MRI-powered Millirobots Using a Self-Assembled Gauss Gun" (ICRA)
And a full-size DIY Gauss gun:
