Dr. Mario Caironi
Mario Caironi is Senior Scientist at the Istituto Italiano di Tecnologia, where he leads the Printed and Molecular Electronics research line. An electronic engineer by training, he is currently the recipient of the European Research Council project Electronic Food (ELFO) on edible electronics.
Dr. Ivan Ilic
Ivan Ilic studied chemistry in Croatia and Germany, earning his PhD while working at the Max Planck Institute on sustainable batteries. He led the development of the edible battery during his postdoc at Istituto Italiano di Tecnologia within the ELFO project.
Imagine ingesting a pill that can tell you how healthy your stomach or intestine is, or asking a sensor in your food if the food is still suitable to eat. Now imaging doing that with electronics made of food, which you can digest! Edible electronics will change the way we live, but they need to be powered by edible batteries.
Electricity powers our world, and with the digitalization of society it is becoming ever more important. Batteries are devices that store electrical energy, powering not only small portable electronic devices, but also cars and even planes in the near future. Many people do not realize that tiny batteries power our bodies, as well! Batteries work when two molecules exchange electrons, producing energy in the process. Likewise, when two of these special molecules reach our enzymes, they power the biochemical machinery of our bodies.
We found a pair of molecules that is suitable for creating edible batteries. Riboflavin, a molecule that occurs naturally in many foods, such as almonds, was used as the molecule that gives electrons. Quercetin, found for example in capers and dried berries, was used as the molecule that takes electrons. This pair of edible molecules is the heart of the battery, which however needs to have wires in order to be useful. So we began by using activated carbon, a home remedy for upset stomach, to anchor the riboflavin and quercetin. Next, inks made of activated carbon and each molecule were painted on wires made from edible gold foil of the sort used by pastry chefs to decorate cakes. The two sides of the battery —the quercetin and riboflavin sides— need to exchange charge, and we allowed this by placing them in a water-based electrolyte. At the same time, in order to avoid short circuits, the two sides must not touch each other. Therefore, we separated them with nori algae, the seaweed found in sushi rolls. To keep the components together, we encased everything in a beeswax capsule, making a truly edible battery.
Ivan Ilic was the brain behind the battery, exploiting his electrochemistry skills and passion for sustainable batteries. His work was complemented by the Edible Electronics research team led by Mario Caironi at Istituto Italiano di Tecnologia. The team is currently addressing other fundamental components of future edible electronic systems, such as edible circuits, edible sensors and communication strategies. At present, the team is busy assembling the first prototypes of edible pills integrating a miniaturized edible battery and an edible circuit meant to monitor the gastrointestinal tract.
For more information: Ilic, I. K., Galli, V., Lamanna, L., Cataldi, P., Pasquale, L., Annese, V. F., Athanassiou, A., & Caironi, M. (2023). An Edible Rechargeable Battery. Advanced Materials (Deerfield Beach, Fla.), 35(20), e2211400. https://doi.org/10.1002/adma.202211400
The edible battery (center), surrounded by the ingredients used to make it (clockwise from top right): almonds, capers, edible gold foil, activated carbon, nori algae, water electrolyte, beeswax.
Photo: G. Berretta / Istituto Italiano di Tecnologia – © IIT, all rights reserved.