Porcupine barbs may inspire new IV needles


This is a microscopic image of a porcupine quill. Harvard medical researcher Jeffrey Karp and his colleagues are studying the quills to determine whether they might inspire a new design in hypodermic needles. According to their paper published today in PNAS, the barbs on the quill enable it to slide in smoothly but keep it in place, characteristics that would be useful in, say, an IV drip. (Smithsonian)


  1. ok, why would want hypodermic needles designed never to come out?  (but instead to work their way inwards, slowly… relentlessly…)

    1. Just guessing but I’m sure part of the focus of this research is to make it hard to retract only some of the time.

  2. Porcupine quills open up like tiny umbrellas when tugged, and remove gobbets of flesh when you pull them out with vise grips.  This process is even more painful than it sounds, and I suspect there’s some sort of irritant chemical under the umbrellas, too.  I’d rather push a porcupine quill through an inch of flesh than pull one out a quarter inch.

    1. Just air as far as I know.
      The quills are hollow and so when you apply pressure to grab it to pull it, it balloons out elsewhere. Most likely inside your dog. The way to get them out is to clip the end off so they deflate and then pull them out with a little twist. Prolly hurts exactly the same. 

  3. People are just too used to having adhesive bandages ripped off – it’s time for something better…


    You could put a bunch of microscopic barbs like this on a bandage for really good adhesion.  Make them out of some kind of biodegradable substance and they’d eventually just disintegrate in the skin.  Even better would be to lace them with a mild antibiotic or other beneficial medicine, so they put micro-doses into the skin as they hold on the bandage as they slowly dissolve. Contact me for where to send those patent royalties :)

    1. I like this idea. If the barbs lasted just long enough to administer the meds, it could be a sort of self notification. 

      If you can pull it out then you know you’ve received your meds and you can pull it out. 

  4. @theophrastvs:disqus  and @google-44fb9c17a22832413cb891dda4c302a8:disqus, I imagine being able to control the micro-workings of the quill or at least a quill like device would be very useful. Turn it on and put it in; when it’s time to take it out turn it off and remove. I could see aplications for usage in mental wards, children’s care units and other situations where the patient has “trouble” keeping the IV in. There would also along that logic be some veterinary uses too.

    I’m glad people do research like this. Sure on the face it may seem ludicrous and ostensibly pointless but it’s curiosity and ingenuity that have gotten the human race to where we are today. (Whether or not that is a good place or not is another debate entirely.)

    1. It would be much more efficient to create a device that is turned “on” for removal, and uses no power to insert or retain.

    2. dam-nit folks, doncha see that this is all cover for eeevil military research?!?  why do you think Iron-man has to wear a magnet over his heart?!

  5. Ah – the Journal PNAS.

    I suppose this may only be funny to those who frequently pronounce it out loud.  At work, we say ‘Pee- NAS’.  That I find this funny makes me little more than a child, but I’m fine with that.

    1. If you pronounce it “P-N-A-S” it only makes it sound like a sillily-pronounced version of the same word.  It’s a foolproof name.

  6. The barbs could be aligned such a way that with a twisting motion, the needle slides back out effortlessly, but general yanks and tugs don’t pull it out, such as catching it on a chair arm or the side of a bed.  Think how an artichoke has its leaves spirally aligned.

  7. This is an incredibly terrible idea.  As soon as someone accidentally steps on an IV line, someone has a big chunk of flesh and vein ripped out, and is now bleeding profusely.  At least tape generally doesn’t rip off flesh.

    1. Next time you fill up at a gas station, have a look at the breakaway connection at the pump end of the fuel line.

      1. That’s even better. Also, I was thinking, maybe not quite as snug as a porcupine quill. Maybe just enough barbs to keep it in more firmly than smooth bare metal, but not so many that it rips the vein out, too. Obvious, some product testing is in order on teristz.

  8. Doing research doesn’t mean they are trying to replicate the porcupine quil. But merely to understand it better and maybe adapt some the things they learn from it to make better needles.

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