Vita gazette – Researchers from the Italian Institute of Technology (IIT) have produced a “fully edible” rechargeable battery using products consumed as food in daily life. The edible battery could be used in health diagnostics, food quality monitoring and edible soft robots.

A team of researchers at the Istituto Italiano di Tecnologia (IIT-Italian Institute of Technology) has created an edible and rechargeable battery, starting from materials usually consumed in our daily diet. Inspired by the biochemical redox reactions in living things, the researchers used almonds, capers and nori algae to develop the battery. Riboflavin used as the anode in the battery, was obtained from almonds, and quercetin, which was used as the cathode, was obtained from capers. In addition, to prevent short circuits, nori seaweed used in sushi was used for the separator required in batteries, while activated charcoal and water-based electrolyte were used to increase electrical conductivity.

The study was realised by the group of Mario Caironi, coordinator of the Printed and Molecular Electronics laboratory of the IIT Center in Milan (Italy); Caironi and his team focused on the study of the electronic properties of foods and their by-products to produce edible electronic materials or electronic devices that can be embedded in edible materials.

The IIT’s research group took inspiration from the biochemical redox reactions that happened in all living beings and developed a battery that utilises riboflavin (vitamin B2, found, for example, in almonds) as anode and quercetin (a food supplement and ingredient present in capers, among others) as a cathode. Activated charcoal (a widespread over-the-counter medication) increased electrical conductivity, while the electrolyte was water-based. The separator, needed in every battery to avoid short circuits, was made from nori seaweed found in sushi. Then, electrodes were encapsulated in beeswax from which two food-grade gold contacts (the foil used by pastry chefs) on cellulose-derived support came out.

The battery cell operates at 0.65 V, a voltage low enough not to create problems in the human body when ingested. It can provide a current of 48 μA for 12 minutes or a few microamps for more than an hour, enough to supply power to small electronic devices, such as low-power LEDs, for a limited time.

The first ever made, this example of an entirely edible rechargeable battery would open the doors to new edible electronic applications.