'Worm robot' could be used to clear life-threatening blood clots

Blood clots that cause strokes and aneurysms could one day be treated by a tiny worm-like robot capable of gliding through narrow pathways such as those found in the brain.

Scientists have developed an ultra-thin thread capable of being steered remotely using magnetic fields, with self-lubricating skin allowing it to move with minimal friction.

It has been put through its paces on an obstacle course made out of small rings and a life-size silicone replica of blood vessels in the brain, and engineers at the Massachusetts Institute of Technology (MIT) say they are confident the technology could eventually be put to life-saving use in hospitals.

Professor Xuanhe Zhao, who specialises in mechanical, civil and environmental engineering at MIT, said: "If acute stroke can be treated within the first 90 minutes or so, patients' survival rates could increase significantly.

"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 development of the robot, which is made from a flexible nickel-titanium alloy and coated in hydrogel, has been detailed in the journal Science Robotics.

Its materials mean it is bendy and springy - ideal for navigating the tight and delicate passages of the human body.

The robot was also tested without the hydrogel coating, but moved slower and the risk of injury to the linings of blood vessels was increased.

If the robot was to be introduced to hospitals, the study envisages doctors being able to operate it using a joystick, even from another room or a different location altogether.

Lead author Yoonho Kim said the next step was to test the robotic thread in a living organism.