Living on Earth’s Cynthia Graber reports on how engineers are designing a painless needle by learning from mosquitoes.
CURWOOD: Coming up, why turkeys are hot to trot right now. First, this environmental Technology Note from Cynthia Graber.
GRABER: When a mosquito bites us its stinger, or proboscis, goes in and out of our skin painlessly. That painful pinch we feel is the anti-coagulant saliva that irritates our skin, and then makes the spot itchy and scratchy. The reason the sting itself is painless is that a mosquito's stinger isn't smooth. Its edges are actually serrated, so fewer points meet sensitive nerve endings. Unlike a mosquito stinger, medical needles are made of smooth metal, and come in contact with nerve endings at every possible point during insertion into our skin.
So engineers in Japan decided to make a painless needle by mimicking the mosquito's design. They cut microscopic jagged edges into silicon dioxide, and then bonded the pieces together. The end result: a needle that's only one millimeter long, and one-tenth of a millimeter in diameter. In preliminary tests, it pierced through a piece of silicone rubber, used to imitate skin.
Right now, this painless needle is too brittle, and could break off after piercing human skin. So engineers are still refining their design for human tests. That's this week's Technology Note. I'm Cynthia Graber.
CURWOOD: And you're listening to Living on Earth.
[MUSIC: Medeski, Martin & Wood, "Smoke," UNINVISIBLE (Blue Note - 2002)]
Living on Earth wants to hear from you!
P.O. Box 990007
Boston, MA, USA 02199
Donate to Living on Earth!
Living on Earth is an independent media program and relies entirely on contributions from listeners and institutions supporting public service. Please donate now to preserve an independent environmental voice.
Sailors For The Sea: Be the change you want to sea.
Innovating to make the world a better, more sustainable place to live. Listen to the race to 9 billion
The Grantham Foundation for the Protection of the Environment: Committed to protecting and improving the health of the global environment.
Energy Foundation: Serving the public interest by helping to build a strong, clean energy economy.
Contribute to Living on Earth and receive, as our gift to you, an archival print of one of Mark Seth Lender's extraordinary hummingbird photographs. Follow the link to see Mark's current collection of photographs.