Some robots are very large. Some can pick up a car as part of the manufacturing process. Other robots are very small, very small. Micro-robotics is not a new field, but great progress is being made to design tiny, speedy, self-propelled robots. They are called microrobots or just plain microbots. The promise is the tiny wonders will be able to travel around inside our body and deliver medications exactly where they are needed.  

Researchers in medical micro-robotics are working hard to create a next-gen drug delivery system. The idea is not a new one, but recent progress may be bringing the vision closer to reality. One of the challenges has been the mode of transportation. Many microbots have relied on blood circulation or diffusion. It can work but limits the ability of the microbot to reach some organs and tissues.

Researchers at the University of Colorado Boulder have developed a new approach to microbot design. They have developed a tiny, self-propelled microbot that can deliver drugs quickly and effectively. When I say “tiny”, I mean hard to imagine small. The picture of one of the microbots below is 20 micrometers in diameter, which converts to .00079 inches. That is approximately one-fourth the diameter of the average human hair.

The researchers observed bacteria and sperm are biological “swimmers”. They can navigate their way around, not is a straight path but making non-linear movements. Take a look at the video at the beginning of the story and you will see what non-linear means.

The Colorado microbot is made from biocompatible polymers. The center is a spherical cavity. The cavity traps air when the microbot is submerged in fluid. The researchers were able to propel the microbot by introducing an acoustic wave, such as an ultrasound. The sound makes the microbot vibrate and the fins enable it to propel itself as you can see in the video.

The researchers made thousands of the microbots. New Atlas, publisher of articles about innovation and human endeavor, reported, “the researchers test-drove their tiny bubble-based, sound-powered speed demons on mice bladders.” They loaded the microbots with dexamethasone, a common steroid medication.  The New Atlas story reported, “When the microbots were introduced, the researchers found that they latched onto the bladder wall and released more than 90% of the dexamethasone over about two days.” The researchers have a vision to cure interstitial cystitis, a chronic condition known as painful bladder syndrome.

The researchers plan to eventually make the microbots fully biodegradable so they can dissolve in the human body after delivering the medication. Jin Lee, the lead author of the research study said, “If we can make these particles work in the bladder, then we can achieve a more sustained drug release, and maybe patients wouldn’t have to come into the clinic as often.”

Read more about robots in healthcare in Robot Attitude: How Robots and Artificial Intelligence Will Make Our Lives Better