Production of hybrid macro/micro/nano surface structures on Ti6Al4V surfaces by picosecond laser surface texturing and their antifouling characteristics

Abstract

The development of surfaces which reduce biofouling has attracted much interest in practical applications. Three picosecond laser generated surface topographies (Ti1, Ti2, Ti3) on titanium were produced, treated with fluoroalkylsilane (FAS), then characterised using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Raman Spectroscopy, Fourier Transform Infra-Red (FTIR) spectroscopy, contact angle measurements and white light interference microscopy. The surfaces had a range of different macro/micro/nano topographies. Ti2 had a unique, surface topography with large blunt conical peaks and was predominantly a rutile surface with closely packed, self-assembled FAS; this was the most hydrophobic sample (water contact angle 160°; ΔG was -135.29mJm). Bacterial attachment, adhesion and retention to the surfaces demonstrated that all the laser generated surfaces retained less bacteria than the control surface. This also occurred following the adhesion and retention assays when the bacteria were either not rinsed from the surfaces or were retained in static conditions for one hour. This work demonstrated that picosecond laser generated surfaces may be used to produce antiadhesive surfaces that significantly reduced surface fouling. It was determined that a tri-modally dimensioned surface roughness, with a blunt conical macro-topography, combined with a close-packed fluoroalkyl monolayer was required for an optimised superhydrophobic surface. These surfaces were effective even following surface immersion and static conditions for one hour, and thus may have applications in a number of food or medical industries.

Fabricating Laser-Induced Periodic Surface Structures on Medical Grade Cobalt–Chrome–Molybdenum: Tribological, Wetting and Leaching Properties

“…When anti-bacterial properties of surfaces found in nature are studied, a correlation between hydrophobicity and anti-bacterial behavior is found [2,31,32]. Since LIPSS have been found to be hydrophobic [10][11][12][13][14][15] and also anti-bacterial [15][16][17][18], hydrophobicity is used in this paper as an indication of anti-bacterial behavior.…”

“…Under specific conditions, this can lead to so called laser-induced periodic surface structures (LIPSS). LIPSS are nanometer sized, regular patterned surface textures and can improve tribological performance [9,10], wettability properties [10][11][12][13][14][15], anti-bacterial properties [15][16][17][18] and cell-tissue growth [11].…”

Controlling bacteria retention on polymer via replication of laser micro/nano textured metal mould

“…The first step of bacterial attachment to a surface is goverened by physicochemical factors which are affected by surface chemistry and topography [1]. In the literature, conflicting results about the influence of hydrophobicity on initial bacterial attachment are found [2][3][4][5][6][7][8][9][10][11][12][13]. Another step of bacterial adhesion and retention to a surface is influenced by the substratum roughness and topography [1,[8][9][10][11][12].…”

“…Another step of bacterial adhesion and retention to a surface is influenced by the substratum roughness and topography [1,[8][9][10][11][12]. Many studies have been carried out to investigate the effect of surface topography on bacterial retention [5][6][7][8][9][10][11][12][14][15][16][17][18][19][20].…”

“…The authors in the cited works focused on studying the wettability and transparency characteristics of the generated polymer replicas. Moreover, the effect of laser surfaces structuring of metallic substrates on bacterial behaviour have been reported [5][6][7]13]. However, limited number of work has been reported on studying the adhesion and fouling characteristic of replicated laser textured metallic surfaces on polymer [41].…”