How porcupines are helping doctors design better needles
Need to build better tools? Look no further than Mother Nature. Sharkskin gave Speedo the inspiration to design a more-streamlined swimsuit. And squirmy, snake-like machines are helping surgeons make fewer incisions when operating on patients. Now, to design a better needle, a team of bioengineers at the Center for Regenerative Therapeutics at Brigham and Women's Hospital in Boston are drawing inspiration from a somewhat unlikely, prickly critter: The North American porcupine. Here's what you should know about the project:
Why the porcupine?
The large rodents are covered in 30,000 pointy quills that help protect them from would-be predators (and any curious dog unlucky enough to come across one). Each quill is several centimeters long with roughly 800 microscopic barbs at the tip. These tiny, invisible hooks make each quill extremely difficult — and not to mention painful — to remove. Yet somehow, the quills are able to slide into flesh with remarkable ease. After studying them up close for the first time, researchers can finally explain why this happens.
Why are the quills so effective at piercing skin?
The barbs have a "dual functionality," says study leader Jeffrey Karp. It doesn't make sense that a barbed quill can penetrate the skin more efficiently than a smooth one, but the team found that they work "like the bumps on a serrated knife," says Nancy Shute at NPR. "The knife's wavy blade concentrates force at the tip of the teeth, requiring less power overall to cut soft foods like tomatoes or bread." In the porcupine's case, that means poking into the flesh of anyone unlucky enough to get too close.
What will this porcupine-inspired needle be like?
Karp and his team are working on prototype needles covered in similarly microscopic barbs that require much less force to penetrate the skin. That means better accuracy and, more importantly, less painful injections.
But how will people, um, remove the needles?
Good question. Researchers are working on making the needle biodegradable so that it can be removed without the characteristic difficulty of real porcupine quills.
What else will they be able to build from these findings?
The grippy barbs may also lead to stronger, band-aid like adhesives that hold tissue together more securely. (Think Velcro.) These adhesives could find a prominent spot in the medicine world as more doctors shy away from using unwieldy staples or time-consuming sutures.