Ivan K. Ilic, first author of the study and a postdoctoral researcher at IIT, told Ars Technica, “Two main ways a battery damages human tissue when it’s inside the body is by doing water electrolysis and by the toxicity of its materials. Water electrolysis is a phenomenon where electricity with a voltage higher than 1.2 V (virtually all commercial batteries) breaks water into oxygen and hydrogen (an explosive gas), and it is very dangerous if it occurs in the stomach. Our battery is way below this voltage, around 0.65 V, so water electrolysis cannot occur. On the other hand, we used only food materials, so nothing is toxic!” Before the battery is useful, however, the researchers will need to first enhance the battery’s power capacity. Currently, the edible battery can supply 48 microamperes of current for a bit over 10 minutes. So it can easily meet the power demand of a miniature medical device or a small LED. “These batteries are no competition to ordinary batteries — they will not power electric cars — but they are meant to power edible electronics and maybe some other niche applications, so their main advantage is non-toxicity,” said Ilic. Here’s a list of what makes these edible batteries work, as mentioned by Ars:
– “Quercetin, a pigment found in almonds and capers, serves as the battery cathode, whereas riboflavin (vitamin B2) makes up the battery anode.
– The researchers used nori (edible seaweed that is used in the wrapping of sushi rolls) as the separator and a water-based solution (aqueous NaHSO4) as the electrolyte.
– Activated charcoal is employed to achieve high electrical conductivity in the battery.
The battery electrodes come covered in beeswax and connect to a gold foil (used to cover pastries) that laminates a supporting structure made of ethyl cellulose.”
The research has been published in the journal Advanced Materials.
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