Full-Field Thickness Measurement of Paint Sensors Using Pulsed Terahertz Waves

This study presents a method for measuring the thickness and adhesion status of paint sensors using pulsed terahertz (THz) waves. Traditional measurement techniques, such as optical, X-ray, ultrasonic (UT), eddy current, and mechanical methods, are prone to accuracy issues and potential sample damage, particularly when evaluating adhesion. The pulsed THz wave approach enables the high-resolution, nondestructive evaluation of both thickness and adhesion status. The analysis of pulsed THz wave reflections from the interfaces of the paint sensor enables accurate measurements of thickness and the detection of adhesion issues. Validation against traditional thickness gauges and UT devices demonstrates the superior performance of the THz-wave-based method, particularly for identifying significant changes in thickness and adhesion defects. Furthermore, a full-field visualization technique is developed to map thickness variations across the entire sensor surface, offering detailed insights into the sensor conditions. The THz-wave-based method represents a significant advancement in nondestructive testing, providing a precise and comprehensive analysis of paint sensors while overcoming the limitations of conventional techniques.