Long-Lasting Hydrophilicity of Al₂O₃ Surfaces via Femtosecond Laser Microprocessing

Area of Science:

• Materials Science
• Surface Engineering
• Nanotechnology

Background:

• Alumina (Al2O3) is a versatile ceramic material with applications in biomedical implants and prostheses.
• Controlling surface wettability is crucial for optimizing the performance and biocompatibility of alumina-based devices.
• Existing methods for surface modification may lack long-term stability or require complex post-processing.

Purpose of the Study:

• To investigate the modulation of alumina wettability using femtosecond laser texturing.
• To demonstrate the creation of stable and durable hydrophilic surfaces on alumina.
• To establish an optimal laser processing regime for tailoring micro-nanostructures and achieving long-term wetting control.

Main Methods:

• Femtosecond laser texturing was employed to create periodic micro-nanostructures with varying groove depths on alumina plates.
• The ablation threshold was determined under the experimental conditions.
• Contact angle measurements were conducted daily for over 40 days to monitor surface wettability, with and without post-process thermal annealing.

Main Results:

• A periodic geometry with triangular patterns was optimized for long-term wetting response.
• Deeper grooves (up to 17.1 µm) significantly enhanced and maintained the hydrophilic character of the alumina surface.
• Superhydrophilicity (contact angle < 5°) persisted for the entire 40-day test duration in samples without post-process thermal annealing.

Conclusions:

• Femtosecond laser texturing offers an effective method for fine-tuning alumina wettability.
• The generated micro-nanostructures provide stable and durable hydrophilic surfaces.
• This technique holds potential for applications requiring long-term control of surface-liquid interactions, such as biomedical implants and prostheses.