Worm-like robotic thread could improve clot-reducing treatments

A tiny worm-like robot capable of gliding through narrow, winding pathways such as those found in the brain has been developed by scientists.

The robotic thread can be steered remotely using magnetic fields, supported by a self-lubricating skin to help it smoothly manoeuvre with minimal friction through its delicate surroundings.

Engineers at the Massachusetts Institute of Technology (MIT) tested the ultra-thin guidewire on an obstacle course of small rings, as well as a life-size silicone replica of the brain’s blood vessels.

They hope that it could one day be used to speed up treatment of conditions such as an aneurysm or a stroke and make existing procedures simpler for surgeons, by doing away with the necessity to physically push a wire around.

“If acute stroke can be treated within the first 90 minutes or so, patients’ survival rates could increase significantly,” said Xuanhe Zhao, associate professor of mechanical engineering and of civil and environmental engineering at MIT.

“If we could design a device to reverse blood vessel blockage within this ‘golden hour’, we could potentially avoid permanent brain damage. That’s our hope.”

The soft robotic design – which is described in the Science Robotics journal – is made from a flexible nickel-titanium alloy, giving it the advantages of being bendy and springy as it makes its way around tight vessels.

Tests of the robotic thread coated in hydrogel showed that it was able to move much faster than one without hydrogel, and reduced the risk of injury to vessel linings.

“Existing platforms could apply magnetic field and do the fluoroscopy procedure at the same time to the patient, and the doctor could be in the other room, or even in a different city, controlling the magnetic field with a joystick,” lead author Yoonho Kim envisages.

“Our hope is to leverage existing technologies to test our robotic thread in vivo in the next step.”