Researchers at the University of Purdue, in the US, have created a miniature pump activated by body heat that could be used in drug delivery patches powered by fermentation.
The micropump contains Baker’s yeast and sugar in a small chamber. When water is added and the patch is placed on the skin, the body heat and the added water cause the yeast and sugar to ferment, generating a small amount of carbon dioxide gas. The gas pushes against a membrane and has been shown to pump continually for several hours, said Babak Ziaie, a Purdue University professor of electrical and computer engineering and biomedical engineering.
Such miniature pumps could make possible drug delivery patches that use arrays of ‘microneedles’ to deliver a wider range of medications than is currently possible with conventional patches. Unlike many other micropump designs, this new technology requires no batteries, said Ziaie, who is working with doctoral student Manuel Ochoa. ‘This just needs yeast, sugar, water and your own body heat,’ Ziaie said.
The robustness of yeast allows for long shelf life, and the design is ideal for mass production, according to Ochoa. ‘It would be easy to fabricate because it's just a few layers of polymers sandwiched together and bonded,’ he explained.
Findings were detailed in a research paper published online in August in the journal Lab on a Chip. The paper was written by Ochoa and Ziaie, and the research is based at Purdue’s Birck Nanotechnology Center in the university’s Discovery Park.
The ‘micro-organism-powered thermopneumatic pump’ is made out of layers of rubberlike polymer polydimethyl siloxane, which is used commercially for diaphragms in pumps. The prototype is 1.5cm long. The researchers have filed a provisional patent application for the device.