Yeast Farts Power Pump for Medical Patches
Researchers are working on a tiny, yeast-filled pump that may power the next generation of medical patches.
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This new medical device doesn't require batteries because it's not powered by electricity. Instead it's essentially powered by yeast farts. Researchers have created a tiny pump, designed to transfer drugs into the body through a patch, that is powered by the carbon dioxide produced by ordinary baker's yeast when the yeast fungi eat.
Medical patches allow drugs to diffuse into the body through the skin ? nicotine patches and contraceptive patches are common ? but many medicines have molecules that are too large to pass through the skin without help. So several researchers have worked on making micropumps that would help push larger drugs into the body through a patch of microneedles that pierce the skin painlessly.
Babak Ziaie, an engineer at Purdue University in Indiana, happened to make one with an unusual power source. [Swallow-able Medical Microchip Gets FDA Approval]
"This just needs yeast, sugar, water and your own body heat," Ziaie said in a statement.
The new pump is a small, flexible silicone bubble with two chambers. The first chamber holds the drug and has a tiny tube coming out of it, to carry the drug into the body. The second chamber holds a mixture of yeast and sugar. Yeast microorganisms normally eat sugar, but without water or heat, they stay dormant and don't eat.
When researchers inject water into the pump and place the pump on someone's skin, the person's body heat is enough to activate the yeast. The one-celled organisms start eating the sugar and producing carbon dioxide as waste, a reaction that's familiar to home bakers who have activated a packet of yeast before adding it to a bread recipe.
The carbon dioxide eventually inflates the yeast-and-sugar chamber of the pump bubble, putting pressure on the other chamber to pump out some of its drug. Ziaie and a doctoral student studying with him, Manuel Ochoa, built a half-inch (15 millimeters) prototype that pumps continually for more than two hours, they reported in August in the journal Lab on a Chip. Ziaie envisioned people just throwing away the patch after the reaction was over.
A yeast-powered pump may be less bulky than battery-powered pumps other researchers have made, Ziaie said. Yeast fungi also are able to live for a long time in a dried state, so patches using a yeast pump should last a long time.
He and Ochoa have filed an application for a patent on the pump.