Effect of Surface Microstructure on the Long-term Anti-bacterial Performance for Slippery Liquid Infused Porous Surfaces

摘要

In the development of biocompatible materials for biomedical applications and biosensors the foreign body response is an important issue [1]. The adhesion of microorganisms on the biosensor surface affects the performance of the biosensor while causing organism infection. The concept of Slippery Liquid Infused Porous Surfaces (SLIPS) provides a new strategy for anti-bacterial adhesion on the surface of biosensors [2]. However, there are still some shortcomings in practical uses, such as the loss of lubricant significantly restricts the long-term slippery performance [3]. Thus, how to lock the lubricant on the surface is a key bottleneck to be solved, and the effect of surface morphology has played critical roles. In this paper, we microfabricated well-controlled microcavity with different profiles (vertical or inclined wall), to investigate the long-term anti-biofouling effect of SLIPS. We explored the microstructure geometry in two aspects: the aspect ratio and the slope angle which are relevant with the Laplace pressure and the oil contact area thus leading to different oil-locking ability. High aspect and incline slope are demonstrated with better oil-locking ability as well as significantly less bacterial adhesion. Under the flow environment rotating at 1000 rpm, the coverage of bacteria adhered to the SLIPS with 20° inclined microcavities is only about 30% of the SLIPS with vertical microcavities, and 4 times aspect ratio brings about 3 times antibacterial effect. On basis of these findings, we propose SLIPS microstructure features with better oil-locking ability and long-term anti-bacterial performance, which provide a theoretical basis for the practical application of SLIPS, such as, medical implanted devices, food package etc.