  The use of natural or bioinspired materials to develop edible electronic
devices is a potentially disruptive technology that can boost point-of-care
testing. The technology exploits devices which can be safely ingested, along
with pills or even food, and operated from within the gastrointestinal tract.
Ingestible electronics could potentially target a significant number of
biomedical applications, both as therapeutic and diagnostic tool, and this
technology may also impact the food industry, by providing ingestible or
food-compatible electronic tags that can smart track goods and monitor their
quality along the distribution chain. We hereby propose temporary tattoo-paper
as a simple and versatile platform for the integration of electronics onto food
and pharmaceutical capsules. In particular, we demonstrate the fabrication of
all-printed Organic Field-Effect Transistors (OFETs) on untreated commercial
tattoo-paper, and their subsequent transfer and operation on edible substrates
with a complex non-planar geometry.
