Printed Eddy Current Testing Sensors: Toward Structural Health Monitoring Applications

Area of Science:

• Materials Science
• Engineering
• Non-Destructive Testing

Background:

• Reliable structural health monitoring (SHM) requires highly reproducible sensor measurements.
• Current instrumentation methods can be limited by reproducibility and human error, especially in challenging environments.

Purpose of the Study:

• To develop and validate a novel method for in-situ sensor fabrication for SHM.
• To assess the feasibility of printing sensors directly onto structural components using conductive and dielectric inks.

Main Methods:

• Investigated combinations of dielectric and conductive inks for optimal performance, with Dupont inks showing superior results.
• Employed dispenser- and screen-printing techniques to fabricate flat spiral coil sensors on flexible substrates.
• Compared printed sensors to traditional flexible printed circuit boards (PCB-flex) with copper circuits.
• Successfully printed 20-turn spiral coil sensors directly onto 3 mm thick stainless-steel plates.

Main Results:

• Conductive ink-based sensors demonstrated efficiency comparable to PCB-flex sensors.
• Printed sensors on stainless steel exhibited good sensitivity, on par with portable sensors.
• The printing method proved feasible for direct application on solid structural parts.

Conclusions:

• Directly printing sensors onto components is a viable solution for achieving reproducible measurements in SHM.
• This technique minimizes human error and is suitable for confined or hazardous environments.
• The developed method is adaptable to various non-destructive testing techniques beyond eddy current testing.