Novel Method for the Rapid Evaluation of the Surface Energies on Film and Window Cover Substrates for Organic Light-Emitting Diode Displays

No existing method can rapidly and quantitatively evaluate the deposition state of antifingerprint nanocoatings over large areas on films and window cover substrates for organic light-emitting diode displays. To address this limitation, we propose a novel method─surface energy mapping and measurement (SEMM)─for ultrafast SE evaluations. The SEMM method integrates vertical and oblique imaging to simultaneously capture and analyze multiple droplets placed over a large area. This method requires considerably less measurement time than conventional side-view methods. Moreover, for regions with high contact angle (CA) values (>90°), SEMM corrects the apparent droplet height using oblique observations, thereby maintaining measurement accuracy. This paper presents a comprehensive overview of SEMM, including its operating principle, hardware setup, image processing techniques, algorithms for calculating CA and SE, and the validation experiments conducted on various surface samples.