Porcupine quills to help develop painless hypodermic needles

London: Inspired by the structure of porcupine quills, researchers are working on less painful hypodermic needles that can penetrate the skin more easily and resist buckling.

The North American porcupine carries an intimidating array of around 30,000 defencive quills on its back which it can bury in the flesh of predators.

The spiky rodents can then shed them before scurrying away. But once lodged in the flesh of their assailants, they are difficult to remove, the `Daily Mail` reported.

Researchers are working to harness porcupine quill`s unique properties to develop surgical super glues, needles and other medical devices as well.

Each quill has a conical tip studded with microscopic backward-facing barbs. These act like serrated blades, providing a cleaner cut through tissue by localising forces at the teeth tips.

As well as anchoring the quill into the flesh, the barbs minimise the amount of penetration pressure needed.

"We were most surprised to find that the barbs in quills serve a dual function," said study leader Dr Jeffrey Karp, from Brigham and Women`s Hospital in Boston, US.

"Namely, the barbs reduce the penetration force for easy insertion into tissue and maximise the holding force to make the quills incredibly difficult to remove," he said.

Studying porcupine quills is expected to lead to improvements in the design of needles and medical adhesives, said the researchers.

"Towards medical applications we developed plastic replicas that remarkably mimicked the reduced penetration force and increased pullout.

"This should be useful to develop next generation medical adhesives and potentially design needles with reduced pain," Karp added.