Eat, Test, Digest: Towards Diagnostic Food for Next-Generation Gastrointestinal Tract Monitoring

The development of edible electronics and robotics represents a novel opportunity in several application scenarios, from food monitoring and healthcare to search and rescue. In this context, the EU-funded ROBOFOOD project aims to merge food science, robotics, and engineering to study the possible application of food-derived materials in traditional electronic and robotic components. Besides the possible out-of-body applications, the use of food-derived materials holds great potential for gastrointestinal (GI) monitoring. Avoiding the use of toxic materials, digestible sensors – i.e. diagnostic food - can reduce the risk of poisoning and retention in case of device malfunctioning, limiting the need for surgical extractions. Here we present an edible pressure-induced contact-resistance pressure sensor made of a gelatin-based body, an activated carbon conductive coating, printed gold electrodes and an ethyl cellulose substrate. Preliminary results show that the sensor is successful in detecting pressure changes above a certain threshold depending on the diaphragm height. For a device with a height of 500 μm, the pressure threshold was between 20.3 and 25.3 g/cm2. While further developments are required to enable the use of the sensor in real-case scenarios, this work represents a first proof-of-concept of diagnostic food.