Saliva-powered microcells could serve as ovulation predictor
UNIVERSITY PARK, Pa., USA: In the scope of a research project that is aimed at investigating new methods of renewable energy recovery, engineers have discovered that saliva-powered microcells can produce amounts of energy sufficient to run lab-on-a-chip diagnostic devices. The researchers believe that these cells could have various applications in medicine. For instance, they could be used as an ovulation predictor based on the conductivity of a woman's saliva, which changes before ovulation.
The team at the Pennsylvania State University has been researching microbial fuel cells (MFCs) that use bacteria to convert organic material in liquids into electricity for more than ten years. According to the researchers, the saliva-powered cells produce nearly 1 μW and thus generate enough power to be directly used as an energy harvester in microelectronic applications.
MFCs may have possible applications in glucose monitoring in diabetes patients, and could also be used as an ovulation predictor. According to the researchers, the conductivity of saliva decreases rapidly five days before ovulation owing to hormonal changes. "Thus, MFCs could be used to measure this change in conductivity to identify the fertility period of a woman, while simultaneously using the power generated to send the data to a readily available device, such as a smartphone," they stated.
The micro-sized MFCs have a single chamber with a graphene-coated carbon cloth anode and an air cathode. While the researchers tested the cells using acetate and human saliva, any liquid with sufficient organic material can be used.
The findings were published online on March 7 in the Nature Publishing Group Asia Materials journal under the title "Energy Harvesting from Organic Liquids in Micro-Sized Microbial Fuel Cells."