Micro Fuel Cell Powered by Saliva Developed
A goal for many researchers is to develop biomedical micro-devices that can collect specific information easily and cheaply. While ultra-low-power chip-size electronics are becoming a reality, powering them is still a question, as the power source must be equally small. Researchers at Penn State may have a solution in the form of a micro microbial fuel cell, which can be powered by saliva.
Microbial fuel cells take advantage of the small amount of electrical charge bacteria produce as they process organic material. By capturing that charge with an anode, it can be run through a circuit to power a device. Microbial fuel cells have been developed before, and often use wastewater, but this new cell is able to operate off of the organic material found in saliva. It further differs from other microbial fuel cells by only using a single chamber with a graphene coated, carbon cloth anode. Other fuel cells possess two chambers and use platinum. Another important difference is it utilizes an open-air cathode, and the researchers do not quite understand why. Normally if oxygen is able to reach the bacteria, no electricity will be produced, but it works in this case, possibly due to the electrodes being microns apart.
Potentially this and similar microbial fuel cells could power devices to measure glucose levels and other useful pieces of information. They may not put out even a full microwatt, but not much is needed for some of these devices.
Source: Penn State