The principle of operation of the electric organ of electric eels, it is possible to repeat in an artificial counterpart.


Electric cell-filled hydrogel with water and salts. (Photo: Thomas B. H. Schroeder, Anirvan Guha.)

Electric cells of different types, spread over two sheets. (Photo: Thomas B. H. Schroeder, Anirvan Guha.)

Electric cells combine with each other several times, folding the sheet on which they sit. (Photo: Thomas B. H. Schroeder, Anirvan Guha.)”

Researchers from the University of Michigan, universities of Fribourg reported in his article in Naturethat they were able to construct a current source operating on the same principle as the electric organ of the electric eel. The eel electric organs are composed of many cells through which the flow of positive potassium and sodium ions; as a result, each cell appears a positively charged pole (toward the fish’s head) and a negatively charged pole (pointing to tail ). Each cell generates a voltage of about 150 mV, but all together, stacked one behind the other, like the batteries, they generate hundreds and hundreds of volts.

Something similar did Michael Mayer (Michael Mayer) and his colleagues. Instead of living cells, they used cells filled with a hydrogel-a polymer that holds water. Hydrogel in cell holds either clean water or water with salts, which in solution into positive and negative ions. The walls of the cells are made of semi-permeable membrane, which allows these ions back and forth. When cells touch each other, the ions start to move in different directions, and an electric voltage is generated.

Hydrogels in the cells are different in their own composition and the composition of the solutions which they hold; if you compare with electric eels cells, the same cell correspond to the four cells (in the photo they are marked in different colours). One block of four cells gives from 130 to 185 millivolts, the experiment managed to make a large “battery” of several hundred cells in total were given to 110 volts.

But the main trick here is in how the battery is made to work. Artificial electric cells in one case, distributed between two flexible polymer sheets: superimposing the sheets on each other, the cells can be combined in the right order (as in photo 2). In another embodiment, they were all placed on the same sheet, but so that they can be combined, folded the sheet several times (as in photo 3). When both of the sheet is squeezed, or when squeezing a folded sheet, any contact directly between all cells and all cells working at the same time.

It is anticipated that such batteries can be used to power various biomedical devices, and, moreover, that such batteries will be able to use the natural energy of some internal tissues and organs. “Prepodobny” batteries more flexible and easier to make biocompatible, so they do not irritate living cells. The problem, however, is that while the voltage that they give is not very large, although the inventors believe that in the near future they will be able to get their battery to generate a current of the same voltage as real electric eels.