Sensors on a plasticized thermoset substrate for cure monitoring of CFRP production

•Interdigital structure for insitu cure monitoring of resin.•Monitoring of Carbon Fiber Reinforced Polymer manufacturing.•Sensorial material by realizing the sensor from the identical material under test.•Dielectric analysis for monitoring the curing of thermoset resin. Embedding sensors for in-situ monitoring of composite manufacturing guarantees high quality and cost-optimized products. For minimally invasive sensor integration, the ideal sensors should be made of identical material of the final host product. Frequently, thermoset resins are used for high-performance fibre reinforced composite in aerospace and automotive industries. A thin layer of cured thermoset resin is rigid and brittle and it cannot be reshaped. Thus, it cannot afford to be the substrate of a sensor if flexibility is required. By adding a plasticizer to the resin, a flexible substrate is produced. The substrate is tested to produce a sensor by using a hollow mask to screen-print interdigital structures. This sensor is used to measure the curing of resin during production of Carbon Fibre Reinforced Polymers (CFRP), known to be electrically conductive. Mechanical tests show a better adhesion of the developed substrate to the host structure compared with commonly used polyimide.