Superhydrophobic surface structures in thermoplastic polymers by interference lithography and thermal imprinting

We present a method to produce superhydrophobic surfaces in thermoplastic polymer substrates. The method involves the creation of a nickel stamp using a customized laser interference lithography technique and electroplating processes. This stamp is used to emboss sub-micrometer periodic structures into the thermoplastic. The modified surface is coated with a hydrophobic plasma-polymerized hexafluoropropene layer. Surfaces with different periodicity and relief depth were created. On the surface with the highest aspect ratio, advancing water contact angles of 167° were measured with a water contact angle hysteresis of below 5°.