Study of Biofilm Growth on Slippery Liquid-Infused Porous Surfaces Made from Fluoropor

Avoiding undesired growth of biofilm is a fundamental challenge for all surfaces in long-term contact with aqueous media. Slippery liquid infused porous substrates (SLIPS) are a promising type of surface for preventing biofilm attachment. The effectiveness of SLIPS is based on the liquid/liquid interface between the medium and the surface, which prevents biofilm attachment. However, the long-term stability of these surfaces is problematic: under shear force, the oil layer is removed and the repellent effect is lost. Here, we study correlations between the porosity of the infused substrate and the ability to uphold the SLIPS oil-film under low shear and high shear force conditions. For this purpose, we manufacture substrates with different porosity and surface roughness in porous fluorinated polymer “Fluoropor”, which we have recently introduced. The porous layers were infused with fluorinated oil and their roughness was studied by white light interferometry. We find that SLIPS samples with smaller pores more effectively reduce Pseudomonas aeruginosa biofilm growth in a seven-day microfluidic flow cell experiment. With its easy production, simple adjustment of porosity and the possibility to attach the polymer to various technical substrates during polymerization, Fluoropor is a very promising material for producing stable SLIPS. When produced with small pores, Fluoropor is also transparent and enables the real-time observation of biofilm growth by optical examination. Thus, Fluoropor SLIPS provides an easy approach to reduce bacteria adhesion and bio fouling in many technical applications.