Capacitive Sensor for Production Monitoring

Recent trend of more complex geometry of FRC is causing increasing difficulties in composite manufacturing. A method to optimize the manufacturing process is to ensure and improve the quality of manufactured parts using cure monitoring based on capacitive sensors.

Capacitive sensor


Left: Schematic of a capacitive sensor; Right: the fabricated sensors.

  • Sensor fabricated in-house by PCB technology
  • Sensor monitors the complex permittivity of the GFRP in real time and in situ, which allows to identify different stages of the production process
  • Sensor dimension: 13mm×11mm×68 µm
  • Sensitivity determined by sensor geometry


Deformable microsystem

Because of the irregular 3D geometry of the composites, traditional flat sensor system is becoming unfavorable and non-practical for monitoring purpose. To accommodate the non-flat shape, the proposal is to interconnect non-deformable functional island, which contains the capacitive sensor for production monitoring, with meander-shaped deformable interconnections.

Left: Setup of a vacuum assisted resin infusion process;
Right: Deformable microsystem containing capacitive sensors is embedded.

  • A vacuum assisted resin infusion process
  • A microsystem containing capacitive and temperature sensors were embedded
  • Meander-interconnects enables deformability