3D-Printed “Micro-Fish” May Soon Be Cleaning Your Bloodstream

In Brief
  • Science fiction has long dreamed of miniature robots capable of cruising our bloodstreams and cleansing our bodies of pathogenic substances.
  • Researchers are working to make this dream a reality with a host of new micro-robots, including tiny magnet-controlled "fish" that remove toxic substances or deliver drugs.

The dream of using nanorobotics to explore or target disease-causing or cancerous elements within the human body is an enduring one. And, sometimes it has seemed that it was destined to be only that and nothing more—an ambitious dream, never to be realized.


However, some researchers are quietly working to make this dream a reality. Professors Shaochen Chen and Joseph Wang of the Nano Engineering Department at the University of California, San Diego, are 3D-printing miniscule robots to target microscopic ailments.

Thinner than the width of a human hair, these robots called “micro-fish” may one day be prescribed by your M.D. Why the name micro-fish? Well, they’re actually designed to look just like fish.

“Micro-fish” can be mass-produced via 3d printing. Image Credit: Forbes

The fish-shape isn’t achieved using a typical 3D printer. You can’t head over to Home Depot, grab a Makerbot, and start printing these guys. The fish were printed using a high-resolution 3D-printing technology called “microscale continuous optical printing,” or μCOP. It’s a new technique that was actually developed by Chen.

The printer uses 2 million tiny mirrors that function and aim individually. As a beam of UV light is projected, the mirrors direct the light at a photosensitive material. The material solidifies when the UV light hits it.

The fish are essentially a “delivery vehicle” for nanoparticles that Chen and Wang attach to their tails. Platinum, nanoparticles react with hydrogen peroxide, and the resulting chemical reaction acts to propel the fish. The fish even have magnetic particles attached to their heads, which help them steer.

Mini-Robots With Guns

These aren’t the only mini-robots designed for use with magnets. Researchers from Boston’s Children’s Hospital and the University of Houston invented “millirobots.” These small magnetic robots are designed to swim through a patient’s bloodstream and spinal fluid. Once inside, they are programmed to assemble into an electromagnetic gun.

Throughout the procedure, a doctor mans the controls, guiding the bots to the fluid build-up or blocked passageway. The bots then inject drugs directly into the target area, advancing targeted treatment possibilities.

Special Delivery

The micro-fish, meanwhile, are remarkably versatile little creatures.

Chen and his team installed particles in the fish that react with toxins such as bee venom. When the two substances meet, the particles glow red. In the experiment, the fish was placed in a solution with the toxin. The fish then “swam through the solution and nabbed the toxin along the way.” Throughout the experiment, the scientists monitored the intensity of the red glow.

So, the fish are able to remove unwanted substances, but they can also deliver needed drugs as well. Chen and his team hope to attempt to use the fish for “targeted drug delivery or as sensors.” The fish seems to be doing exactly what the scientists intended, delivering “treatment to an otherwise difficult to access part of the body without causing ill effects.”

Our bodies won’t soon be full of micro-fish as the technology is still in development. But, this project has been backed by grants from the National Science Foundation and the National Institutes of Health. This means that there’s a great deal of hope that someday this technology—which seems only possible in fiction—may be coming to a doctor’s office near you.

Sarah Marquart