Reusable mechano-bactericidal surface with echinoid-shaped hierarchical micro/nano-structure.

Area of Science:

• Materials Science
• Biotechnology
• Surface Chemistry

Background:

• Biofilms on surfaces cause significant problems in industries like marine transportation and medicine.
• Mechanobactericidal surfaces, inspired by insect wings, offer a physical method to kill bacteria by deforming their membranes.
• Accumulation of dead bacterial debris on these surfaces reduces their long-term effectiveness.

Purpose of the Study:

• To develop a self-cleaning nanostructured surface that maintains its bactericidal properties over time.
• To investigate the efficacy of thermal cleaning in removing bacterial debris and restoring surface function.

Main Methods:

• Fabrication of a hierarchical micro/nano-structured surface with echinoid-shaped nanotextures on aluminum micro-particles using pressure-less sintering.
• Evaluation of the surface's intrinsic bactericidal efficiency against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).
• Application of thermal cleaning at 500°C to remove accumulated bacterial debris and assessment of the restored bactericidal activity.

Main Results:

• The fabricated surface demonstrated high initial bactericidal efficiency against E. coli (97%) and S. aureus (80%).
• Thermal cleaning effectively removed dead bacterial debris, preserving the aluminum oxide nanostructure.
• Post-cleaning, the surface maintained significant mechano-bactericidal activity (E. coli: 89%, S. aureus: 75%) and this efficacy was sustained over five cycles.

Conclusions:

• Hierarchical nanostructured surfaces can effectively kill bacteria through physical membrane deformation.
• Thermal cleaning is a viable strategy to remove bacterial debris, restoring and sustaining the mechano-bactericidal effect.
• This approach offers a promising solution for long-lasting antimicrobial surfaces in various industrial applications.