The battery you can eat

2023-05-07 18:18:43

The intention is not to revolutionize the culinary art. The objective is medical. In fact, there is a genuine area of research called, for lack of a better term, “edible electronics.” edible electronics) that attempts to produce devices exclusively from ingredients that are part of a normal diet or from food additives.

In theory, such devices could be used to diagnose gastrointestinal disorders without having to introduce a probe. They could also be used to analyze the quality of (real) food ingested. Some breakthroughs have been reported in recent years. For example, a Californian team designed in 2017 an “electrochemical detector” capable of detecting certain specific molecules (uric acid, ascorbic acid, acetaminophen). A team of four institutions from China and the United States, in 2017and another from Italy in 2022have developed devices capable of communicating with each other.

The feasibility of “edible” devices therefore no longer needs to be demonstrated. But the difficulty so far has been their energy source: without batteries, they have too limited a lifespan to be medically more useful than so-called invasive techniques, such as the probes used for colonoscopy.

According to researchers from the Italian Institute of Technology, who published their results in March in Advanced Materials, their battery operates at 0.65 volts, which is too low to create problems in the human body. It uses riboflavin (vitamin B2, found in certain types of mushrooms) as an anode (one of the two “poles” of a battery) and quercetin (an antioxidant found among others in capers) as cathode. The separator, which keeps the anodes and cathodes apart to prevent a short circuit, is made of algae used in particular in sushi. The electricity generated can power a micro-device between 12 minutes and a little over an hour, depending on the energy demand.

It wouldn’t be enough to run an electric car, quips in the press release co-author Ivan Ilic. But “this is proof that batteries can be made of safer materials than current lithium-ion batteries” and that this could be an avenue for future engineers to explore.