Imagine you are sick and go to a hospital for treatment. The doctors discover a blood clot in one of your arteries. The clot blocks the blood supply, preventing the blood from delivering oxygen to a particular spot in the body. Without oxygen, the cells there soon die. Now, to remove the blood clot and get the blood flowing again, surgeons use blood thinners and flexible instruments, but some blood vessels in the body are too difficult to reach.
Swimming through blood
Researcher Islam Khalil's tiny robots can make it to those hard-to-reach spots. A spinning magnet on a robotic arm deftly steers the tiny robot through winding blood vessels. It seems simple, but to make it work, quite a few obstacles have to be overcome. For instance, the robots must be powerful enough to swim against the blood flow. At the same time, a doctor must be able to control them accurately so that they do not damage blood vessels during their journey through the body.
In the experiments with these robots, the researchers made the robots swim through a real aorta. Fake blood flowed through the aorta at 120 millilitres per minute. That does not seem like a lot, but it is equivalent to 180 litres of blood per day, as much as flows through your kidneys. Using an X-ray machine, the researchers monitored the robots. The robots swam stable straight stretches going both with and against the current. This worked with one, but also with several robots at the same time.
Many applications
Their screw-shaped bodies enable the robots to pierce blood clots and remove them. But more applications can be imagined. Like small trucks, they could deliver medicines very precisely. That way the medicine gets to where it is needed and much less to unwanted places in the body. That way, you have minimal side effects of drugs.
