Printed Integrated Logic Circuits Based on Chitosan‐Gated Organic Transistors for Future Edible Systems

Abstract

Edible electronics made of materials that can be safely ingested is researched for applications in food monitoring, drug delivery, and gastrointestinal tract screening, addressing sustainability and e‐waste concerns. Edible electronics can also endow future edible robots with sensing and control. In this work, the realization of building blocks of future edible computing units is tackled. Potentially edible unipolar NOT and NAND logic gates, as well as a ring oscillator, based on an inkjet‐printed, p‐type electrolyte‐gated organic transistor, are demonstrated. Food additives and derivatives are used for electrodes, passivation layers, and the electrolyte. A well‐known biocompatible conjugated polymer is printed in the micrograms range to form the transistors active layer and the load resistors. A cascade in vitro digestion assay applied to the transistors do not reveal adverse effects on an intestinal cell epithelium model. The transistor is optimized for operation at low voltage and for low leakage, allowing the logic circuits to operate below 0.7 V, compatibly with recently developed edible energy sources. These results demonstrate the possibility of realizing low‐voltage logic circuitry with scalable fabrication approaches exploiting potentially edible functional materials, moving toward future control electronics for food monitoring and healthcare.