An Internet-of-Things Enabled Flexible Strain Sensor for Stem Growth Measurements

This paper reports on the development of a screen-printed flexible strain sensor and integration with an internet-of-things platform with applications in stem growth monitoring in live plants. The sensor was formed on a flexible polyimide sheet by coating a reduced graphene oxide layer on top of graphene interdigitated electrodes. The overall size of the sensor was 2-centimeter by 2-centimeter. The real-time resistance variations of the sensor were measured remotely via the Blynk-based internet-of-things platform. The presented sensor was calibrated with cylinders of different diameters, to mimic stem growth monitoring.