First-ever rechargeable edible battery made of vitamins and nori seaweed can power small devices

For the longest time, Mario Caironi, coordinator of the Printed and Molecular Electronics laboratory of the IIT Center in Milan (Italy), has been studying the electronic properties of food and its by-products, to integrate them with edible materials and create new edible electronic materials. The study was realized with Caironi's group, a press release stated.

All-you-can-eat batteries made of vitamins and seeweed

The IIT’s research group took inspiration from biochemical redox reactions that takes place in all living beings.

They developed a battery that employs riboflavin (vitamin B2, found for example in almonds) as the anode and quercetin (a food supplement and ingredient, present in capers, among others) as the cathode. According to the release, activated charcoal was used to increase electrical conductivity, while the electrolyte was water-based. The separator, needed to avoid short circuits, was made from nori seaweed, the kind found in sushi. Then, electrodes were condensed in beeswax from which two food-grade gold contacts on cellulose-derived support come out.

The battery cell operates at 0.65 V, a voltage that is 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.

"Future potential uses range from edible circuits and sensors that can monitor health conditions to the powering of sensors for monitoring food storage conditions. Moreover, given the level of safety of these batteries, they could be used in children's toys, where there is a high risk of ingestion," Caironi said in a statement. "Actually, we are already developing devices with greater capacity and reducing the overall size. These developments will be tested in the future also for powering edible soft robots," he added.

"Building safer batteries, without the usage of toxic materials, is a challenge we face as battery demand soars. While our edible batteries won’t power electric cars, they are proof that batteries can be made from safer materials than current Li-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.

The proof-of-concept battery cell has been described in a paper, recently published in the Advanced Materials journal. 

Study Abstract:

Edible electronics is a growing field that aims to produce digestible devices using only food ingredients and additives, thus addressing many of the shortcomings of ingestible electronic devices. Edible electronic devices will have major implications for gastrointestinal tract monitoring, therapeutics, as well as rapid food quality monitoring. Recent research has demonstrated the feasibility of edible circuits and sensors, but to realize fully edible electronic devices edible power sources are required, of which there have been very few examples. Drawing inspiration from living organisms, which use redox cofactors to power biochemical machines, a rechargeable edible battery formed from materials eaten in everyday life is developed. The battery is realized by immobilizing riboflavin and quercetin, common food ingredients, and dietary supplements, on activated carbon, a widespread food additive. Riboflavin is used as the anode, while quercetin is used as the cathode. By encapsulating the electrodes in beeswax, a fully edible battery is fabricated capable of supplying power to small electronic devices. The proof-of-concept battery cell operated at 0.65 V, sustaining a current of 48 µA for 12 min. The presented proof-of-concept will open the doors to new edible electronic applications, enabling safer and easier medical diagnostics, treatments, and unexplored ways to monitor food quality.