Photoacoustic nondestructive evaluation for material characterization: recent advances and future perspectives

Photoacoustic (PA) nondestructive evaluation (NDE) is an emerging material characterization approach that converts optical absorption into acoustic information, enabling simultaneous access to optical absorption, structural features, and depth-dependent properties. Unlike conventional inspection techniques, PA NDE provides unique capabilities for quantitative evaluation of complex materials and structures. This Perspective summarizes recent advances in PA NDE platforms, including PA A-line sensing, PA microscopy, and all-optical PA systems such as PA remote sensing, and highlights their applications in energy storage, semiconductor manufacturing, civil infrastructure, transportation, aerospace, and other industrial fields. Representative examples demonstrate the potential of PA NDE for defect inspection, morphology monitoring, and material property characterization. Future development will require advances in non-contact inspection, wavelength-selective characterization, quantitative signal interpretation, image-based analysis, and measurement standardization. These efforts will be essential for translating PA NDE from laboratory demonstrations into reliable industrial characterization tools.