LONDON: Scientists have created the world’s first saliva-powered micro-sized microbial fuel cell that can produce minute amounts of energy sufficient to run on-chip applications.
Microbial fuel cells create energy when bacteria break down organic material producing a charge that is transferred to the anode.
By producing nearly one microwatt power, this saliva-powered, micro-sized MFC generates enough power to be directly used as an energy harvester in microelectronic applications, scientists said. While the researchers tested this mini microbial fuel cell using acetate and human saliva, it can use any liquid with sufficient organic material.
An international team of engineers, headed by Bruce E Logan, professor of environmental engineering at Penn State University, who has studied microbial fuel cells for more than 10 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. The researchers believe emergence of ultra-low-power chip-level biomedical electronics, devices able to operate at sub-microwatt power outputs is becoming a reality.
One possible application would be a tiny ovulation predictor based on the conductivity of a woman’s saliva, which changes five days before ovulation. The device would measure the conductivity of the saliva and then use the saliva for power to send the reading to a nearby cell phone.
Biomedical devices using micro-sized microbial fuel cells would be portable and have their energy source available anywhere.