Edible Electronics for Sustainable Agrifood: Towards the Integration of Edible Rechargeable Batteries with Sensor Networks

Abstract

As sensor networks become increasingly used in every step of the agricultural food chain, sustainability remains an underdeveloped aspect when implementing agrifood monitoring systems. Although electronics experienced exponential growth yielding to ultra-low power systems, most sensing nodes employ commercial batteries that are constituted by potentially harmful chemicals and might leak into the environment producing irreversible damage.Here we present a feasibility study aimed at demonstrating the compatibility of a recently developed edible rechargeable battery with commercial sensors for agrifood. The edible battery is completely made of edible materials, namely foodgrade gold, ethyl cellulose, beeswax, activated carbon, riboflavin, quercetin, sodium hydrogen sulfate, and nori algae. As such, the battery does not contain any hazardous substances and can be disposed of by a variety of means, including composting. We demonstrate the integration of the battery with commercial thermistors and photoresistors to measure temperature and light intensity, respectively, which are relevant parameters in agricultural food production. We show that the performance of the edible battery is suitable for supplying power to commercial sensors therefore demonstrating its great potential for sustainable agrifood systems.

A Sprayable Electrically Conductive Edible Coating for Piezoresistive Strain Sensing

“…Finally, at the end of their lifetime, edible devices can be disposed of or repurposed in the same way as food waste. [9,10] These peculiar properties open previously unconceived scenarios: in agrifood, edible sensors can be applied in direct contact with food for quality monitoring, [11] for instance tracking fruit growth using strain sensors; [12] in healthcare, miniaturized edible systems can be engineered to acquire diagnostically relevant information for gastrointestinal (GI) tract monitoring before being metabolized by the body, eliminating the risks associated with retention of ingestible technologies; [13−16] edible robots, equipped with a range of sensors, could also deliver nutrition to humans in an emergency, [11,17] or act as drug-loaded prey for wild animals. [18] Identifying edible materials with electronic properties compatible with industrial processing methods and suitable for implementing edible sensors remains an open challenge.…”