Drexel University researchers have demonstrated how their microswimming robots can deliver medicine to targeted areas and perform surgery inside the body.

The “microswimmers” are essentially beads that come together in order to reach faster speeds when travelling through a liquid.

Once they’ve reached their target, the beads can separate and be individually controlled to deliver their medicinal payload or targeted treatments.

“We believe microswimmer robots could one day be used to carry out medical procedures and deliver more direct treatments to affected areas inside the body,” said U Kei Cheang, PhD, and postdoctoral research fellow in Drexel’s College of Engineering, U Kei Cheang.

“They can be highly effective for these jobs because they’re able to navigate in many different biological environments, such as the blood stream and the microenvironment inside a tumour.”

When linked, the microswimming robots move by spinning, and the more the robots spin the faster they move.

In a paper published in Nature Scientific Reports, the researchers documented how the longest chain that was examined by the group – 13-beads in length – was able to reach speeds of 17.85 microns per second.

This dynamic propulsion system is also the key to getting the robots to divide into shorter segments.

Once the robots reach a certain rate of rotation the chain separates and smaller beads remain that can move independently of each other.

Having separated, the robots can be manipulated and made to move in different directions if required.

“To disassemble the microswimmer we simply increased the rotation frequency,” Cheang said.

“For a seven-bead microswimmer, we showed that by upping the frequency 10-15 cycles the hydrodynamic stress on the swimmer physically deformed it by creating a twisting effect, which leads to disassembly into a three-bead and four-bead swimmer.”

Drexel University is partnering with ten institutions of research and medicine from around the world to develop this technology for performing minimally invasive surgery on blocked arteries.

But the work it has been doing on microswimmer robots represents the culmination of nearly a decade’s work into understanding the biomedical applications of microrobots.

“For applications of drug delivery and minimally invasive surgery, future work remains to demonstrate the different assembled configurations can achieve navigation through various in vivo environments, and can be constructed to accomplish different tasks during operative procedures,” the study’s authors write.

“But we believe that the mechanistic insight into the assembly process we discussed in this research will greatly aid future efforts at developing configurations capable of achieving these crucial abilities.”