A tiny robot with 'caterpillar' legs could be used to carry drugs inside the human body.

Researchers behind the technology say it has the equivalent strength of a human able to lift a 26-seat minibus.

It can adapt to adverse environments and move efficiently along surfaces within the body lined with, or entirely immersed in, body fluids such as blood or mucus.

But what makes the 'milli-robot' stand out is its hundreds of less than one millimetre long pointed legs that look like tiny hairs.