Thermal aging of conductive and dielectric inks for flexible printed electronics: Toward reliable strain gauge application

Printed electronics (PEs) offer notable advantages in various sectors such as low-cost production, multifunctionality, and flexibility. Technology enables the creation of complex, scalable, and adaptable structures on lightweight substrates, which is particularly valuable for the development of Internet of Things (IoT) devices. These devices facilitate real-time data monitoring, promoting sustainability and cost efficiency for applications in condition monitoring by tracking machinery health to detect failures early. While previous studies have explored printed sensors for such applications, there remains a significant lack of data on the environmental durability of the inks used—particularly under varying temperature and humidity conditions. This study addresses that gap by systematically evaluating the aging behavior of commercially available conductive and dielectric inks used in screen printing. Inks were deposited as multilayer structures on flexible substrates and subjected to various controlled environmental tests. The results provide new insights into the comparative aging stability of ink types: conductive inks demonstrated consistent electrical performance throughout aging, while dielectric inks showed somehow degradation, impacting sensor functionality. These findings contribute to a deeper understanding of material behavior in realistic operational environments and confirm the selection of robust materials for printed sensor systems. Ultimately, this work supports the development of reliable metal strain gauges for integration into reusable space launch platforms. • Printed electronics offer low-cost production, multifunctionality, and flexibility. • Condition monitoring improves sustainability and reduces maintenance costs. • Harsh environment aging tests are conducted to assess sensor reliability. • Commercial conductive inks show high performance for metal strain gauges.