Abstract
Biofilm-associated infections caused by an accumulation of micro-organisms and pathogens significantly impact the environment, health risks, and the global economy. Currently, a non-biocide-releasing superhydrophobic surface is a potential solution for antibacterial purposes. This research demonstrated a well-designed robust polydimethylsiloxane (PDMS) micro-structure and a flame treatment process with improved hydrophobicity and bacterial anti-adhesion properties. After the flame treatment at 700 +/- 20 degrees C for 15 s, unique flower-petal re-entrant nano-structures were formed on pillars (PIL-F, width: 1.87 +/- 0.30 mu m, height: 7.76 +/- 0.13 mu m, aspect ratio (A.R.): 4.14) and circular rings with eight stripe supporters (C-RESS-F, width: 0.50 +/- 0.04 mu m, height: 3.55 +/- 0.11 mu m, A.R.: 7.10) PDMS micro-patterns. The water contact angle (WCA) and ethylene glycol contact angle (EGCA) of flame-treated flat-PDMS (FLT-F), PIL-F, and C-RESS-F patterns were (133.9 +/- 3.8 degrees, 128.6 +/- 5.3 degrees), (156.1 +/- 1.5 degrees, 151.5 +/- 2.1 degrees), and (146.3 +/- 3.5 degrees, 150.7 +/- 1.8 degrees), respectively. The Escherichia coli adhesion on the C-RESS-F micro-pattern with hydrophobicity and superoleophobicity was 42.6%, 31.8%, and 2.9% less than FLT-F, PIL-F, and Teflon surfaces. Therefore, the flame-treated C-RESS-F pattern is one of the promising bacterial anti-adhesion micro-structures in practical utilization for various applications.
