Experimental study of fluid slip on drag reducing polymeric surfaces patterned by CO₂ laser system

Lotus leaf bio-inspired drag reducing surfaces have been a topic of interest

for many researchers due to their application in field of anti-icing, self cleaning, drag

reducing surfaces. The aforementioned surfaces achieve their low surface drag by

reducing contact between solid and liquid by using micro-structures that trap air

between the structures and allow fluid to flow over them with reduced shear. So far

the application of these surfaces in various fields are well known along with the drag

reducing mechanism. However, when it comes to fabricating these micro-patterned

surfaces artificially, the techniques used like photolithography, dry reactive ion

etching (DRIE) etc), are quite cumbersome and require many additional resources. This

limits the use of these drag reducing surfaces to just the laboratory environment and

hence, there is a need to find fabrication method that would allow for much simpler and

faster fabrication of drag reducing surfaces. To solve this problem, we use CO₂ laser

system and micro-patterned polymer surfaces. CO₂ laser system fabrication method

is a single step surface patterning method that allows for both easy and large scale

production of these surfaces. Combined with low surface energy of polymeric

surfaces, drag can be reduced dramatically.