This microbial fuel cell runs on saliva. I wonder if there will come a day when we’ll be able to spit on our digital devices to charge them? You can click here for Professor Logan’s page about the devices and see one in action (but only if you have a Windows Movie Player???)
Saliva-powered micro-sized microbial fuel cells can produce minute amounts of energy sufficient to run on-chip applications, according to an international team of engineers. Bruce E. Logan, Evan Pugh Professor and Kappe Professor of Environmental Engineering, Penn State, credited the idea to fellow researcher Justine E. Mink. “The idea was Justine’s because she was thinking about sensors for such things as glucose monitoring for diabetics and she wondered if a mini microbial fuel cell could be used,” Logan said. “There is a lot of organic stuff in saliva.”
Microbial fuel cells create energy when bacteria break down organic material producing a charge that is transferred to the anode. Logan, who has studied microbial fuel cells for more than ten years, usually looks to wastewater as a source for both the organic material and the bacteria to create either electricity or hydrogen, but these tiny machines are a bit different.