Langmuir, Vol.26, No.2, 1191-1198, 2010
Thermal/Plasma-Driven Reversible Wettability Switching of a Bare Gold Film on a Poly(dimethylsiloxane) Surface by Electroless Plating
We report an approach for fabricating a tunable wettability surface by electroless gold plating on poly(dimethylsiloxane) (PDMS). A two-layer Structured gold film with a tight layer and a loose layer can be obtained oil the surface of a PDMS chip when the PDMS chip is immersed in I gold plating solution at 30 degrees C for 4 h. Its wettability can be rapidly switched between superhydrophilicity and superhydrophobicity by plasma and heat treatments without any self-assembled monolayer, and the superhydrophobicity can be even changed from the gecko-foot-hair-like character to the lotus-leaf-like character. Benefiting from the various wettabilities of the prepared gold/PDMS composites, protein patterning is successfully achieved on a patterned superhydrophobic/superhydrophilic gold/PDMS composite; a superhydrophobic needle for transferring supersmall water droplets (1 mu L) to a superhydrophobic surface is successfully fabricated.