Ont. researchers create plant-based micro-robots to help with medical procedures

A team of researchers at the University of Waterloo have created advanced materials that will become the foundation for a new era of soft medical micro-robots.

Chemical engineering professor Hamed Shahsavan is leading the way with these tiny robots, which have the potential to conduct medical procedures such as biopsies and cell and tissue transports in a minimally invasive way without the syringes or catheters usually needed.

For now, they're a maximum of one-centimetre long and here's the catch – they're plant-based.

In creating the devices, Shahsavan said the team asked themselves: “How can we shoot the surgeons inside the body?”

The answer involved making robots out of advanced hydrogel composites that include sustainable cellulose nanoparticles derived from plants.

“They are not toxic. They don't show any immune response or foreign body response,” Shahsavan said.

The robots can move through confined and flooded areas, like the human body, and deliver delicate and light cargo, like cells or tissues, to a target position.

Shahsavan says the hydrogel used in this work changes its shape when exposed to external chemical stimulation. That enables researchers to program shape-change.

Magnetism also helps movement of the robots through the body. Researchers moved the tiny robot through a maze, as an example, to show how it would maneuver inside the human body.

A programmable soft robot navigates through a maze in a proof of concept. (Submitted/University of Waterloo)

“Expose them to electric magnetic field, or different temperatures or even acidity, alkalinity and then they change their shape. Instead of isotropically, same in all directions, they change their shape in a way we dictate it,” Shahsavan said.

Researchers can trigger a shape-change in the robots essentially at will – making them curl or twist, prompting them to pick things up and drop them off.

“It's not going to replace your open heart surgery but it's going to cover many grounds that could be covered non-invasively,” Shahsavan said.

The next step in this research is to scale the robot down to submillimetre scales.

Although the team believes we’re still about a decade off from seeing these type of device in our hospitals, it’s a big step towards more minimally invasive medical procedures.

You can learn more about the research here.