Biocompatible Blends of an Intrinsically Conducting Polymer as Stretchable Strain Sensors for Real‐Time Monitoring of Starch‐Based Food Processing

Abstract Because stretchable strain sensors that have a resistance or capacitance sensitive to strain can sense skin deformation during physical movement, they have been extensively studied as wearable devices for healthcare monitoring. In principle, they can be used to monitor starch‐based food processing in real time, since starch‐based food can have remarkable volume change during processing. Monitoring starch‐based food processing in real time can help achieve high quality and high productivity while reducing energy consumption. Nevertheless, there is no such report in the literature. Here, a blend of starch and a biocompatible intrinsically conducting polymer, poly(3,4‐ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS), is reported as a stretchable strain sensor to monitor starch‐based food processing including fermentation, steaming, storage, and refreshing in a real‐time manner. The resistance of the blends increases during the food volume expansion mainly caused by the fermentation, steaming, and refreshing, and it decreases as a result of the food volume shrinkage during cooling or storage. The signals can be thus used to optimize the processing conditions and control the food quality. This technology can be easily combined with the Internet of Things.