Injectable microscopic robots promise 'dream' breakthrough in surgery

Microscopic robots, which could be injected into the brain to smother a tumour, are a step closer after researchers created the first moving microchips.

Cornell Universityproved it was possible to attach legs or swimming arms to tiny computer chips (smaller than the width of a human hair) which can then be programmed walk to a pre-set location.

It would allow surgeons of the future to access difficult tumours without damaging nearby tissue.

The tiny bots are five microns thick, the size of a single-celled organism, and so could travel through the bloodstream or into tissues.

Lead researcher Itai Cohen, Prof of Physics at Cornell, said: “It’s a tiny computer, and our group has been trying to figure out how to put legs on this computer and make it walk, in essence making a robot out of a computer chip.

“Imagine a surgical arena where a patient is lying on an operating table and a surgeon has reached a region that is too difficult to operate on, maybe a tumour is attached to a very sensitive part of the brain. 

"Instead of reaching for a scalpel the surgeon reaches for a syringe and injects thousands of these tiny little robots.

“These robots then sense the kind of chemicals that are being excluded by the tumour, they move towards it, they shrink wrap around it, and that stops the growth in its tracks. 

"That’s the dream anyway. Everyone of those individual steps can be engineered today.”

The microchips are first designed in 2D graphene and have legs attached, but then can fold up into 3D and begin walking once an electric current is applied. 

Each bot consists of a simple circuit made from silicon light panels, which functions as the torso and brain, and four tiny electrochemical moveable legs.

The researchers control the robots by flashing laser pulses at different light panels, each of which charges up a separate set of legs. 

By toggling the laser back and forth between the legs, the robot is able to walk or swim away. The research is published in the journal Nature. 

Dr Marc Miskin, an assistant Prof at the University of Pennsylvania, said: "Controlling a tiny robot is maybe as close as you can come to shrinking yourself down.

"I think machines like these are going to take us into all kinds of amazing worlds that are too small to see."