Superhydrophobic porous silicon surfaces

In this paper, we present an inexpensive technique to produce superhydrophobic surfaces from porous silicon. Superhydrophobic surfaces are a key technology for their ability to reduce friction losses in microchannels and their self cleaning properties. The morphology of a p-type silicon wafer is modified by an electrochemical wet etch to produce pores with controlled size and distribution and coated with a silane hydrophobic layer. Surface morphology is characterized by means of scanning electron microscope images. Large contact angles are observed on such surfaces and the results are compared with classical wetting models (Cassie and Wenzel) suggesting a mixed Wenzel-Cassie behavior. The presented technique represents a cost-effective means for friction reduction in microfluidic applications, such as lab-on-a-chip. © 2011 IFSA.