[tt] Micro-robot that can clear arteries

[Hughes, James J.]

Telegraph

21/10/2007

Micro-robot that can clear arteries

http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/10/21/nrobot12
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A microscopic robot small enough to travel through blood vessels has
been built by scientists.

Less than a millimetre in size, the robot walks like a crab on six legs
and has been designed to clear blocked arteries.

It was produced by researchers at Chonnam National University in Korea,
who found the robot was able to travel 55 yards in a week.

Once inside a blocked artery, it is able to release drugs to dissolve
blood clots, which are often the cause of heart attacks.

The robot has three short front legs and three longer back legs which
are attached to a central rectangular body.

By attaching grafted heart muscle to the legs, the scientists found the
legs would bend as the muscle cells contracted. The cells get their
energy from sugar in the patient's blood.

That means the robot does not need an external power supply, which are
often heavy and cumbersome, if not impractical.

Because the robot's three front legs are shorter than the back legs,
they bend inwards as the heart muscles contract, creating a difference
in friction that pushes the robot forward.

Using cells from the patient's own body - perhaps grown from stem cells
- would also reduce the likelihood of the body producing an immune
reaction, which might destroy the tiny robot before it could clear a
blockage.

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