A swarm of robots swims through an eye for the first time
In hardly any other field are the advances in medical technology as reminiscent of science fiction novels and films as in nano research. Recently, a team of researchers reported on special nanorobots that are able to cross human tissue and swim freely in an eyeball. In the future, the tiny robots will be used to bring drugs into the body exactly where they are needed.
Researchers at the Max Planck Institute for Intelligent Systems have developed a specially coated nanopropeller that is able to manoeuvre through dense tissue, such as that of a vitreous body in the human eye. Until now, nanorobots could only be controlled by liquids. By overcoming solid tissue, nanorobotics has reached a new level in medical technology. The results of this research were recently presented in the specialist journal “Science Advances”.
Operations without intervention
As the international research team reports, the further development of nanorobots is a major step for medical technology. In the foreseeable future, it will be possible to carry out a large number of therapies without major surgical intervention, where surgery is still required today. The nanorobots could be used as minimally invasive tools that apply active substances exactly where they are needed, without first having to pass through the gastrointestinal tract or the bloodstream.
The smallest propeller machine in the world
The propeller-shaped nanorobots are just 500 nanometers wide. This means that they are 200 times smaller than the diameter of a human hair. According to the research team, this makes them so small that they can slip through the close-meshed network of a solid tissue, such as is present in the vitreous body of the eye. “Their helical structure, size and slippery coating allow the nanopropellers to move relatively freely through an eye without damaging the delicate tissue around them,” writes the Max Planck research team.
Inspired by nature
Since the consistency inside the eye is particularly sticky and tough, researchers used a very special two-ply non-stick coating to prevent the robots from getting stuck in the tissue or interfering with each other. “The coating was inspired by nature,” explains study author Zhiguang Wu in a press release.
What do carnivorous plants and nanorobots have in common?
“We applied a liquid layer to the nanopropellers, as found in the carnivorous pitcher plant (Nepenthes),” explains Wu. The leaves of the pitcher plant create a kind of pitfall. When insects land on them, they find no grip on the slippery coating and fall inside, where they are digested by a liquid. According to the researchers, the same coating ensures that the nanorobots do not get stuck in the eye. “As slippery as the Teflon coating of a frying pan,” comments Wu.
Magnetic drive through the eye
The small robots can be controlled from the outside. They are driven by magnetism. According to scientists, iron particles built into the propeller make it possible to steer the mini-trails to the desired target in a magnetic field.
Not only usable in the eye
“The magnetic drive of the nanorobots, their sufficiently small size and the slippery coating are not only in the eye, but can also be useful for penetrating other tissues in the human body,” adds Tian Qiu, another author of the study. So far, the propeller robots have only been tested within dissected pig’s eyes. Using a small needle, tens of thousands of screw-shaped robots could be injected into the eye. The robots then move together as a swarm.