Remember the movie Fantastic Voyage from way back in 1966? In that film, a submarine with its crew was somehow shrunk to microscopic size and injected into the bloodstream of an injured scientist to repair damage to his brain. In addition to featuring Raquel Welsh in a clingy body suit, the film had great special effects showing the sub passing through various parts of the body.

Miniaturized tools that move through the bloodstream to repair damage was science fiction then, but they may now be on the verge of becoming reality. Instead of a mini sub with a crew, a swarm of microrobots (also called nanobots or nanorobots) could be injected into the body to deliver a highly targeted dose of a drug or radioactive seeds to treat cancer, or to clear a blood clot, or perform a tissue biopsy, or to build a scaffold around an area where new cells need to be grown.

A swarm of microrobots would be very, very precise when it came to things like delivering drugs directly to a tumor. That would be a huge improvement on injecting the drug into the bloodstream and damaging noncancerous cells along with the cancerous ones. Microbots could help with lots of other problems as well. Right now, drugs that treat the retina are injected into the eye, where they slowly diffuse. Only a fraction of the drug actually reaches the target. Microbots laden with drugs could potentially deliver them in a more targeted manner. That would give better results with a much smaller dose and fewer side effects and unwanted interactions.

Heart attacks and strokes happen when blood clots block arteries. If you’re having a heart attack, the clot can be removed by inserting a catheter with a balloon tip into your arm or groin, snaking it up to the blockage, and inflating the balloon to open the artery. This current procedure could be replaced by one that simply injects a swarm of microbots that go to the area and drill out the blockage. Right now, treating a blocked artery in the brain is difficult—catheters don’t work very well and drugs to break up the clot are risky. Microbot drills could really revolutionize stroke treatment.

Microrobots could also help with disease diagnosis. At Johns Hopkins University, researchers have developed microgrippers, star-shaped devices that measure less than 500 micrometers from tip to tip—about the size of a speck of dust. The grippers are made of materials that respond to environmental factors, like temperature and pH and enzymes. The temperature-sensitive gripper arms will close when exposed to the body’s heat, for example. After being put in the correct place using a standard endoscopy tool, the arms close around a tiny piece of tissue to do a miniature biopsy. Each microgripper also contains a tiny bit of magnetic material, so a magnetic tool is used to retrieve them.

Right now, biopsies are an invasive procedure using needles or scalpels to get the tissue sample for examination under the microscope. They’re painful and open you up to the risk of infection, and sometime they miss the right area. A swarm of microbots with grippers could do basic biopsies by taking a number of much smaller tissue samples. Statistically, that’s more accurate than taking just a few larger samples from the suspect area. Even though a lot of grippers will need to be used, the experience will be much easier for the patient, with very little pain and better results.

From removing body blockages to obtaining tissue samples to drug delivery, microbots could transform the future of invasive procedures, making them more precise, less painful and lessen the need to open up the whole body for one targeted procedure.

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