AFM-based micro/nano-scale lithography of poly(dimethylsiloxane) – stick-slip on a ‘soft’ polymer

Abstract

Silicone rubbers have steadily gained importance in industry since their introduction in the 1960's. Poly(dimethylsiloxane) (PDMS) is a relatively soft and optically clear, two-part elastomer with interesting and, more importantly, useful physical and electrical properties. Some of its common applications include protective coatings (e.g., against moisture, environmental attack, mechanical and thermal shock and vibrations), and encapsulation (e.g., amplifiers, inductive coils, connectors and circuit boards). The polymer has attracted recent interest for applications in soft lithography. The polymer is now routinely used as a patterned micro-stamp for chemical modification of surfaces, in particular Au substrates. Prominent stick-slip effects, surface relaxation and elastic recovery were found to be associated with micro/nano manipulation of the polymer by an AFM-based contact mode methodology. Those effects provide the means to explore in detail the meso-scale tip-to-surface interactions between a tip and a soft surface. The dependence of scan speed, loading force, attack angle and number of scan lines have been investigated.