Simultaneous Manipulation of the Optical and Wettability Properties of Metal Surfaces Using 150 kHz Femtosecond Fiber Laser

• Main Authors: Mazhar Iqbal, Vadim Ialyshev, Vyacheslav Kim, Ganjaboy Boltaev, Dmitry Ivanov, Baerbel Rethfeld, Rashid Ashirovich Ganeev, Ali Sami Alnaser
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Applied Sciences
• Subjects: nano-structuring; surface functionalities; recoloring; optical and wettability properties
• Online Access: https://www.mdpi.com/2076-3417/10/18/6207

We demonstrate the formation of permanent and iridescent colors on aluminum, copper, steel, and brass surfaces using femtosecond laser-induced periodic and non-periodic nanostructuring. We show that both the permanent and iridescent colors of the metal surfaces can be erased and re-colored using a second stage of laser processing. A correlation was found between the spectral reflective properties of the laser-processed surfaces and their wettability properties. Transition from superhydrophilic to superhydrophobic response is observed while tailoring the optical reflectance of the metal surfaces. We employ a high power femtosecond fiber laser at 150 kHz repetition rate, which notably reduces the processing time, making this technique attractive for practical applications.