Edible Transistors: from Fabrication to Tips for Storage

Edible electronics is a newly-minted field born to overcome the inherent environmental impact and health hazards of ingestible devices and finally enable point-of-care diagnostic, monitoring, and therapy of different gut diseases. In recent years, research efforts have been devoted to understanding food electronic properties and developing intrinsically safe-to-ingest new material composites and devices, to confirm the feasibility of the edible electronics paradigm. Thanks to the recent realization of stable and reproducible fully edible electrolyte-gated field effect transistors (EGOFETs) that operate at low voltage (<1V), the fabrication of electronic circuits can be envisioned. To move in such a direction, it is fundamental to assess the robustness of edible electronic devices to different environmental conditions, as well as to the mechanical stresses they might undergo during their use.In this work, we test the resilience of edible transistors to a relative humidity range from 10% up to 90% and to tensile stress by applying bending radii down to 1 mm. In both cases, the fully edible transistors show a high degree of resilience, retaining their electrical performances and even showing an improvement when slightly bent (5 mm radius) and when in a damp environment (90% relative humidity). Lastly, we combine the two aspects, by rolling the transistors into a commercial 000 pill and placing them inside a fridge, corroborating our previous findings by showing not only performance retention but also a threefold improvement, proving the robustness of edible transistors for future uses in edible capsules.