A team of scientists led by Associate Professor Isao Shitanda of Tokyo University of Science has just published a study Describes a New Array Design for Biofuel Cells That Use a Chemical in Sweat, Lactic acid, To generate sufficient power to operate a biosensor and walkie-talkie for a short period of time.
More power than previous designs
The new biofuel cell array looks like a paper bandage that can be worn, for example, on an arm or forearm. It mainly consists of a hydrophobic paper substrate on which multiple biofuel cells are placed in series and parallel; The number of cells depends on the output voltage and the required power.
In each cell, electrochemical reactions between lactic acid and an enzyme are present on the electrodes It produces an electric current, Which flows into a general stream collector made of conductive carbon paste.
he is Not the first lactic acid-based biofuel cell, But there are a few key differences that make this new design special. One of them is the fact that the entire machine can be made by screen printing, a technology generally suitable for inexpensive mass production. This is made possible by a careful selection of materials and an innovative design. For example, while similar previous cells use silver wires as the conductive paths, current biofuel cells use porous carbon ink.
Another feature is the way lactic acid is delivered to cells. Layers of paper are used to collect sweat and transfer it to all cells simultaneously through the capillary effect, the same effect that water travels quickly. Through a napkin when in contact with a pool of water.
It also transfers more energy: They can generate a voltage of 3.66V and an output power of 4.3MW.