Recent technological advances have enabled the incorporation of electronic enabled sensors directly into paper products. In one example, electronic packaging can verify medicine authenticity and emails can be sent confirming when the package is opened by the correct person at the correct address. Until recently, it wasn’t economically feasible to produce packages and labels with sensors. The EU-funded ROPAS (Roll-to-roll Paper Sensors) project has overcome this challenge. To achieve its aims, the project incorporated the technology using low-cost and high-throughput roll-to-roll (R2R) and sheet-to-sheet (S2S) printing. It developed a technological platform that integrates printed building blocks consisting of a paper substrate, conductive tracks, , an antenna, a battery and sensor switches. Three applications have demonstrated ROPAS technologies. A security tag makes it possible to determine whether a package has been opened. A smart label enables customers to verify radio frequency identification-coded information easily for use in, for example, brand protection and privacy applications. In addition the smart label is equipped with a temperature and humidity sensor, monitoring the history of a package. And finally a smart envelope providing tracking and personal delivery services at a high security level mimicking registered mail at a lower cost. During the project, the team optimised the technical building blocks, and completed functional prototypes for all three demonstrators. One promising application that project researchers worked on was the fabrication of the organic radical battery (ORB). As technology related to this application is quite novel the team filed a patent application for the ORB electrolyte synthesis methodology. In parallel, R2R and S2S trials enabled commencement of mass production of the demonstrators. Scientists improved the printing processes using flash sintering to cure the conductive ink at high speed on paper and made progress on placement of components. A patent was filed for the smart envelope technology which promises a substantial potential market. The European paper industry requires innovative and cost-effective ways to add value to its products in order to remain competitive. ROPAS delivered a solution with building blocks for the next generation of multi-functional fibre-based products for multi-billion euro market sectors including food, packaging, medicine and logistics.
Smart paper, electronic packaging, printing, organic radical battery, flash sintering, ROPAS