New breakthrough in edible electronics: Scientists create first edible rechargeable battery

A research team from the Italian Institute of Technology (IIT) has successfully created a completely edible rechargeable battery made from materials commonly found in our daily diet. This innovative technology is expected to play a role in health diagnostics, food quality monitoring and edible soft robotics. The research results have been published in the journal Advanced Materials.

It is understood that edible electronics is a new field that has emerged in recent years. It can have a significant impact on the diagnosis and treatment of gastrointestinal diseases and food quality monitoring. One of the most interesting and challenging issues in future edible electronic systems is how to achieve edible power sources.

Drawing inspiration from biochemical redox reactions in living organisms, the Italian Institute of Technology team developed a battery that uses riboflavin (vitamin B2, such as in almonds) as the anode and quercetin (a food additive and ingredient, such as in capers) as the cathode. To increase conductivity, they used edible activated carbon (a common over-the-counter drug), and the electrolyte is water-based. To avoid short circuits, each battery has a separator, which they used nori, the kind in sushi. Then, they wrapped the electrodes in beeswax and led to two food-grade gold contacts (the gold foil used by Western chefs) from a cellulose-derived scaffold.

The cell operates at 0.65 volts, which is low enough not to cause problems when ingested by humans. It can deliver 48 μA for 12 minutes, or a few microamps for more than an hour, enough to power some small electronic devices, such as low-power LED lights, for a while. This fully edible, rechargeable battery is a world first and will open the door to new edible electronic applications.

"Possible future applications range from edible circuits and sensors that monitor health conditions to sensors that monitor food storage conditions. And, given the safety of these batteries, they could also be used in children's toys, which have a high risk of being swallowed. In fact, we are already developing devices with even greater capacity and smaller size. These developments will also be used to power edible soft robots in the future," says Mario Caironi, coordinator of the study.

“Such edible batteries are also extremely valuable to the energy storage community. Creating safer batteries without using toxic materials is a challenge we face as demand for batteries surges. While our edible batteries won’t power electric vehicles, they demonstrate that it is possible to build batteries with materials that are safer than current lithium-ion batteries. We believe they will inspire other scientists to build safer batteries for a truly sustainable future,” added Ivan Ilic, co-author of the study.