Chinese researchers propose robots that swim upstream in blood

BEIJING, Dec. 16 (Xinhua) -- Chinese researchers have proposed an on-wall-rotating strategy for untethered magnetic millirobots to move upstream in blood vessels, according to a study published in the journal IEEE Xplore.

Cardiovascular disease (CVD) is one of the leading causes of death worldwide, and approximately 80 percent of CVD deaths are caused by heart attack and stroke.

Despite the many types of millirobots that have been developed for mini-invasive CVD treatment, swimming against the fast blood flow remains a massive challenge due to the lack of the ability to stay still and the large fluidic resistance from blood.

To address these problems, researchers from the Shenzhen Institute of Advanced Technology under the Chinese Academy of Sciences and the Hong Kong University of Science and Technology have proposed a design scheme of streamlined millirobots and an on-wall-rotating strategy that is easier for clinical application.

The combined design of elliptical arc and parabola reduces the fluid resistance of the robots by approximately 58.5 percent compared to conventional robots. The on-wall motion pattern allows the robots to advance along the wall of the blood vessel where the fluid resistance is lower, further reducing the resistance by about 30.7 percent compared to the classic approach of moving in the center of the blood vessel.

To explore the clinical potential of the new strategy, the researchers tested the robot's moving ability in porcine blood vessels. They found it passed through the vessels in 26 seconds, verifying the robot's ability to move against the blood flow.