Remarkable technology: An illustration of the workings of one of the minute medical robots designed by the Monash University team. The device shown here is an earlier model that was larger than the current version, which is just 0.25 mm across.
Credit: James Friend/Monash University
PARIS: In 1966, the movie "Fantastic Voyage" recounted the tale of doctors who are miniaturised along with a submarine and injected into the body of a Soviet defector, sailing up his bloodstream to destroy a brain clot that imperils the VIP's life.
More than 40 years later, some of the futuristic potential of "Fantastic Voyage" has taken a step closer to realisation, thanks to a remarkable achievement in miniaturisation unveiled this week.
Two or three human hairs wide
There's no submarine or Raquel Welch, but instead a motorised robot that its inventors believe is small enough to be injected into the human bloodstream.
One day, the remote-controlled bot could carry sensor equipment for observation work, relaying images back to surgeons. Or it could become a tiny surgeon, cutting away blood clots, reaming out clogged arteries or repairing damaged tissue, its inventors hope.
The "microbot" measures just a quarter of a millimetre, or "two or three human hairs wide," said lead scientist James Friend, from the Nanophysics Laboratory at Monash University, Australia.
"We are looking for something that can be placed in human arteries, especially in locations where it can't be done with the technologies that were around previously," he said.
Piezo-electricity
Conventional methods of "keyhole" and other minimally invasive surgery today use tubes called catheters, which are inserted into body cavities and arteries. But catheters are rigid and despite their small size can still puncture thin arterial walls.
In a paper published this week in the Journal of Micromechanics and Microengineering, Friend's team describe prototype work on a motor based on piezo-electricity, the energy used in quartz watches, upmarket cigarette lighters and gas-stove lighters.
Piezo-electric materials are ceramics or crystals that generate a voltage in response to mechanical stress.
In this case, the materials vibrate a corkscrew-like microstructure inside the bot that then drives a 'propellor' comprising soft flagella.
Like a swimming bacterium – but guided externally by remote control – the robot would make headway against the bloodstream, at least in blood vessels where the flow is not too great, the inventors hope.
