Printed Radiation Sterilization Monitoring Sensor

To achieve an effective sterilization of medical equipment without altering its unique characteristics, continuous monitoring of gamma radiation sterilization process is essential. Therefore, in this study, we have developed a screen-printed low-cost radiation sensing platform that exploits the variation in electrical impedance of semi-interpenetrating polymer network (SIPN) composed of poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS) and polyvinyl alcohol (PVA). In this polymeric composite, PEDOT: PSS acts as the electrically conductive medium, while PVA provides ductility and stability to the printed sensor. During the radiation exposure, the chain scission and cross-linking events take place, which leads to the formation of SPIN with reduced electrical conductivity. The FTIR, UV-Vis and TGA characterization tools were used to verify the simultaneous scissoring of the PEDOT polymer chain and crosslinking of the PVA polymer network. A systematic optimization of different ratios of PEDOT:PSS and PVA mixtures was performed and observed that PEDOT: PSS/PVA composites with 10wt% PVA exhibited 30% relative impedance change after exposing with 25 kGy and up to 370% after 53 kGy with an excellent stability. These findings enabled us to conclude that the screen-printing technology can potentially be used for a large-scale manufacturing of low-cost radiation sensors which can monitor the radiation sterilization processes more efficiently.