The electric organ of the electric eel consists of long electrocytes, which are controlled by the nervous system and generate a weak voltage, which can, however, add up to 600 V. Sodium ions flow into the cell and potassium ions flow out of the cell. The battery of the researchers from the Adolphe Merkle Institute is based on the same principle . It uses the different salt content of freshwater and saltwater chambers, which are separated by ion-selective membranes, reaching up to 110 V. The technology is still far from the power of an Electrophorus electricus.

The new technique consists of a hydrogel, a polymer capsule that contains water and is permeable by salt ions. It is assembled by means of a 3D printer on transparent plastic films. In order to simultaneously bring all the printed cells into contact with each other, the printed film is folded in a kind of origami technique. The scientific report was published in mid-December in the Nature journal .

A biocompatible, self-charging energy source is the desideratum of the hour, especially for medical technology. For example, the procedure could eliminate the need for pacemaker replacement surgery or provide contact lenses with an integrated display.