Printed electronics based environmental and bio sensors fabrication and performance tuning through optimized structures and materials

Abstract

This research work focuses on the development of high performance sensing devices through all printed fabrication methods. The targeted sensors include environmental and bio‐monitoring devices. Humidity and temperature sensors have been developed under the category of environmental sensors while multi‐reagent immunosensors and human posture detection sensors lie under the category of bio‐sensors. The aim of this research was to improve the performance parameters like sensitivity, selectivity, range of detection (RoD), limit of detection (LoD), response time, recovery time, robustness, stability, and accuracy. The output response curve shape linearity was also targeted and easy to interface readout signals were preferred for the devices. All these targets were achieved through interdisciplinary research in three major fields including appropriate electronic material selection and synthesis, device structure optimization through device physics and sensing mechanism, and compatible printing based fabrication system and process optimization to realize the devices. After fabrication, the sensors were characterized to evaluate their performance parameters through in‐house developed highly accurate and reliable characterization setups. The devices were then interfaced with specifically designed electronic circuits to employ them in real‐life applications for environmental monitoring and point of care (POC) diagnosis for various diseases and conditions. The humidity sensors developed in this research work outperform the reported sensors in literature and have at least comparable or better properties than the commercially available sensors in the market. The temperature sensor is capable of recording the data in both terrestrial and aquatic environments with RoD well suitable for general environmental monitoring. The immunosensors and the POC setup developed in this research is capable to detect multiple bio‐reagents crucial for early diagnosis of various diseases with high sensitivity and with LoD and RoD well within the required clinical range of detection. In short, this research work successfully presents unique combination of multiple fields of study to optimize and improve the performance of sensing devices.