Preparation of Ni-C thin films for strain sensor applications in new hybrid laminates with thermoplastic matrix

Hybrid laminates with thermoplastic matrices offer clear advantages over laminates based on thermosetting resins. These include the formability, recyclability as well as the suitability for mass production, to name a few. The inline integration of smart systems like sensors and actuators in the hybrid laminates during the hot-pressing process is one of the long-term objectives of the Federal Cluster of Excellence MERGE. This work aims to deposit Ni-C thin films by dc magnetron sputtering on polyimide substrates for the application as strain sensors in hybrid laminates. During the first step hybrid laminates containing different polyimide foils were prepared by hot-pressing, this was followed by the mechanical testing and selection of the most suitable polyimide substrate for the Ni-C thin film deposition. The second part consisted of depositing Ni-C thin films by means of dc magnetron sputtering and utilising different Ni-C plug targets. The films were characterised regarding their growth rate, composition, structure and temperature coefficient of electrical resistance.